Publications by authors named "Robyn P M Saw"

77 Publications

Treatment of in-transit melanoma metastases using intralesional PV-10.

Melanoma Res 2021 Mar 18. Epub 2021 Mar 18.

Melanoma Institute Australia Faculty of Medicine and Health, The University of Sydney, Sydney Department of Melanoma and Surgical Oncology, Royal Prince Alfred Hospital, Camperdown Breast and Melanoma Surgery Unit, Royal North Shore Hospital, St Leonards, New South Wales, Australia.

Melanoma in-transit metastases (ITMs) can sometimes be difficult to manage by surgical excision due to their number, size or location. Treatment by intralesional injection of PV-10, a 10% solution of rose bengal, has been reported to be a simple, safe and effective alternative, but more outcome data are required to confirm its value in the management of ITMs. Two hundred and twenty-six melanoma ITMs in 48 patients were treated with intralesional PV-10 supplied under a special-access scheme. By 8 weeks a complete response in all injected ITMs was achieved in 22 patients (46%) and a partial response in 19 patients (40%). Of 19 patients who had uninjected metastases, 3 (16%) had a response in these. The most common adverse event was transient localised pain in injected tumours. New ITMs developed in 25 patients within 8 weeks, and later in another 8 patients. Repeat injection cycles were given to 21 patients: 13 of these received repeat injection into partially responding or nonresponding tumours, 5 had new ITMs, as well as partially-responding lesions injected, and 3 received injection into new ITMs only. Twenty-two patients received subsequent systemic therapy. At 1 year 37 of the 48 patients were alive, 28 with melanoma, and at 2 years 27 were alive, and 19 with melanoma. Injection of PV-10 was simple and safe and resulted in tumour involution in most patients and sometimes in noninjected tumours. However, many patients developed new lesions; these were treated by further PV-10 injections or with alternative therapies.
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http://dx.doi.org/10.1097/CMR.0000000000000729DOI Listing
March 2021

Neoadjuvant ipilimumab plus nivolumab in synchronous clinical stage III melanoma.

Eur J Cancer 2021 Mar 15;148:51-57. Epub 2021 Mar 15.

Department of Medical Oncology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands; Division of Molecular Oncology and Immunology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands; Department of Internal Medicine, Leiden University Medical Center, Albinusdreef 2, 2333 Leiden, the Netherlands. Electronic address:

Background: Patients with synchronous clinical stage III melanoma can present with primary melanoma lesions, locally recurrent melanoma or in-transit metastases. Neoadjuvant ipilimumab plus nivolumab induces high pathologic response rates and an impressive relapse-free survival in patients with nodal macroscopic stage III melanoma. Whether primary site melanoma and in-transit metastases respond similarly to lymph node metastases with neoadjuvant immunotherapy is largely unknown. Such data would clarify whether surgical excision of these melanoma lesions should be performed before neoadjuvant therapy or whether it could be deferred and performed in conjunction with lymphadenectomy following neoadjuvant immunotherapy.

Patients: Patients with synchronous clinical stage III melanoma were identified from the OpACIN, OpACIN-neo and PRADO neoadjuvant trials, where all patients were treated with ipilimumab plus nivolumab. An additional case treated outside those clinical trials was included.

Results: Seven patients were identified; six patients had a concordant response in primary site melanoma lesions or in-transit metastasis and the lymph node metastases. One patient had concordant progression in both the primary and nodal tumour lesions and developed stage IV disease during neoadjuvant treatment, and thus, no resection was performed.

Conclusion: Pathologic response following neoadjuvant ipilimumab plus nivolumab in primary site melanoma lesions or in-transit metastasis is concordant with a response in the lymph node metastases, indicating that there may be no need to perform upfront surgery to these melanoma lesions prior to neoadjuvant treatment.
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http://dx.doi.org/10.1016/j.ejca.2021.02.012DOI Listing
March 2021

Pathological response and survival with neoadjuvant therapy in melanoma: a pooled analysis from the International Neoadjuvant Melanoma Consortium (INMC).

Nat Med 2021 02 8;27(2):301-309. Epub 2021 Feb 8.

Melanoma Institute Australia, The University of Sydney, Sydney, Australia.

The association among pathological response, recurrence-free survival (RFS) and overall survival (OS) with neoadjuvant therapy in melanoma remains unclear. In this study, we pooled data from six clinical trials of anti-PD-1-based immunotherapy or BRAF/MEK targeted therapy. In total, 192 patients were included; 141 received immunotherapy (104, combination of ipilimumab and nivolumab; 37, anti-PD-1 monotherapy), and 51 received targeted therapy. A pathological complete response (pCR) occurred in 40% of patients: 47% with targeted therapy and 33% with immunotherapy (43% combination and 20% monotherapy). pCR correlated with improved RFS (pCR 2-year 89% versus no pCR 50%, P < 0.001) and OS (pCR 2-year OS 95% versus no pCR 83%, P = 0.027). In patients with pCR, near pCR or partial pathological response with immunotherapy, very few relapses were seen (2-year RFS 96%), and, at this writing, no patient has died from melanoma, whereas, even with pCR from targeted therapy, the 2-year RFS was only 79%, and OS was only 91%. Pathological response should be an early surrogate endpoint for clinical trials and a new benchmark for development and approval in melanoma.
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http://dx.doi.org/10.1038/s41591-020-01188-3DOI Listing
February 2021

Performance of Long-Term CT and PET/CT Surveillance for Detection of Distant Recurrence in Patients with Resected Stage IIIA-D Melanoma.

Ann Surg Oncol 2021 Jan 3. Epub 2021 Jan 3.

NHMRC Clinical Trials Centre, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia.

Background: Follow-up for patients with resected stage IIIA-D melanoma may include computed tomography (CT) or positron emission tomography (PET)/CT imaging to identify distant metastases. The aim of this study was to evaluate the test performance over follow-up time, of structured 6- and 12-monthly follow-up imaging schedules in these patients.

Methods: We conducted a retrospective analysis of consecutive resected stage IIIA-D melanoma patients from Melanoma Institute Australia (2000-2017). Patients were followed until a confirmed diagnosis of distant metastasis, end of follow-up schedule, or death. Test accuracy was evaluated by cross-classifying the results of the test against a composite reference standard of histopathology, cytology, radiologic imaging, and/or clinical follow-up, and then quantified longitudinally using logistic regression models with random effects.

Results: In total, 1373 imaging tests were performed among 332 patients. Distant metastases were detected in 110 (33%) patients during a median follow-up of 61 months (interquartile range 38-86), and first detected by imaging in 86 (78%) patients. 152 (68%) patients had at least one false-positive result. Sensitivity of the schedule over 5 years was 79% [95% confidence interval (CI) 70-86%] and specificity was 88% (95% CI 86-90%). There was no evidence of a significant difference in test performance over follow-up time or by American Joint Committee on Cancer (AJCC) substage. The positive predictive value ranged between 33 and 48% over follow-up time, reflecting a ratio of 1:2 false-positives per true-positive finding.

Conclusions: Regular 6- or 12-monthly surveillance imaging using CT or PET/CT has reasonable and consistent sensitivity and specificity over 5-year follow-up for resected stage IIIA-D melanoma patients. These data are useful when discussing the risks and benefits of long-term follow-up.
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http://dx.doi.org/10.1245/s10434-020-09270-3DOI Listing
January 2021

Whole-genome sequencing of acral melanoma reveals genomic complexity and diversity.

Nat Commun 2020 10 16;11(1):5259. Epub 2020 Oct 16.

QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.

To increase understanding of the genomic landscape of acral melanoma, a rare form of melanoma occurring on palms, soles or nail beds, whole genome sequencing of 87 tumors with matching transcriptome sequencing for 63 tumors was performed. Here we report that mutational signature analysis reveals a subset of tumors, mostly subungual, with an ultraviolet radiation signature. Significantly mutated genes are BRAF, NRAS, NF1, NOTCH2, PTEN and TYRP1. Mutations and amplification of KIT are also common. Structural rearrangement and copy number signatures show that whole genome duplication, aneuploidy and complex rearrangements are common. Complex rearrangements occur recurrently and are associated with amplification of TERT, CDK4, MDM2, CCND1, PAK1 and GAB2, indicating potential therapeutic options.
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http://dx.doi.org/10.1038/s41467-020-18988-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7567804PMC
October 2020

Clinical outcomes following surgical treatment of lentigo maligna of the head and neck.

Eur J Surg Oncol 2020 Sep 23. Epub 2020 Sep 23.

Sydney Medical School, The University of Sydney, Sydney, Australia; Institute of Academic Surgery, Royal Prince Alfred Hospital, Sydney, Australia; Department of Plastic and Reconstructive Surgery, Royal Prince Alfred Hospital, Sydney, Australia; Department of Melanoma and Surgical Oncology, Royal Prince Alfred Hospital, Sydney, Australia. Electronic address:

Introduction: Lentigo maligna (LM), a subtype of melanoma in-situ commonly occurring in the head and neck region, often presents a treatment challenge due to anatomical constraints, particularly on the face of mostly elderly patients. This study sought to assess the clinical outcomes of wide local excision of head and neck LM, identify predictors of recurrence and define optimal excision margins.

Materials And Methods: Patients with LM treated between January 1997 and December 2012 were identified from the large institutional database of a tertiary center and their data were analyzed.

Results: In 379 patients, 382 lesions were eligible for analysis. Median maximal lesion diameter was 10.5 mm. The mean surgical excision and histopathological clearance margins were 6.2 mm and 4.0 mm, respectively. Median follow-up was 32 months. The LM recurrence rate was 9.9%, and subsequent invasive melanoma developed in 2.3% of cases (mean Breslow thickness 0.7 mm). The recurrence rate was 27.2% if the histological margin was <3.0 mm (median time to recurrence 46.5 months) compared with 2.6% if the margin was ≥3.0 mm. The mean surgical margin required to achieve a histological clearance of ≥3.0 mm was 6.5 mm.

Conclusions: Our data suggest that to minimize recurrence, a histological margin of ≥3.0 mm is required. To achieve this, a surgical margin of ≥6.5 mm was required. This is greater than the 5 mm margin recommended in some national guidelines. Careful long-term follow-up is required for all patients because of the risk of recurrence.
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http://dx.doi.org/10.1016/j.ejso.2020.09.028DOI Listing
September 2020

Tumor Mutation Burden and Structural Chromosomal Aberrations Are Not Associated with T-cell Density or Patient Survival in Acral, Mucosal, and Cutaneous Melanomas.

Cancer Immunol Res 2020 11 11;8(11):1346-1353. Epub 2020 Sep 11.

Melanoma Institute Australia, The University of Sydney, North Sydney, New South Wales, Australia.

Tumor mutation burden (TMB) has been proposed as a key determinant of immunogenicity in several cancers, including melanoma. The evidence presented thus far, however, is often contradictory and based mostly on RNA-sequencing data for the quantification of immune cell phenotypes. Few studies have investigated TMB across acral, mucosal, and cutaneous melanoma subtypes, which are known to have different TMB. It is also unknown whether chromosomal structural mutations [structural variant (SV) mutations] contribute to the immunogenicity in acral and mucosal melanomas where such aberrations are common. We stained 151 cutaneous and 35 acral and mucosal melanoma patient samples using quantitative IHC and correlated immune infiltrate phenotypes with TMB and other genomic profiles. TMB and SVs did not correlate with the densities of CD8 lymphocytes, CD103 tumor-resident T cells (Trm), CD45RO cells, and other innate and adaptive immune cell subsets in cutaneous and acral/mucosal melanoma tumors, respectively, including in analyses restricted to the site of disease and in a validation cohort. In 43 patients with stage III treatment-naïve cutaneous melanoma, we found that the density of immune cells, particularly Trm, was significantly associated with patient survival, but not with TMB. Overall, TMB and chromosomal structural aberrations are not associated with protective antitumor immunity in treatment-naïve melanoma.
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http://dx.doi.org/10.1158/2326-6066.CIR-19-0835DOI Listing
November 2020

Design and Testing of a Custom Melanoma Next Generation Sequencing Panel for Analysis of Circulating Tumor DNA.

Cancers (Basel) 2020 Aug 10;12(8). Epub 2020 Aug 10.

Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia.

Detection of melanoma-associated mutations using circulating tumor DNA (ctDNA) from plasma is a potential alternative to using genomic DNA from invasive tissue biopsies. In this study, we developed a custom melanoma next-generation sequencing (NGS) panel which includes 123 amplicons in 30 genes covering driver and targetable mutations and alterations associated with treatment resistance. Analysis of a cohort of 74 stage III and IV treatment-naïve melanoma patients revealed that sensitivity of ctDNA detection was influenced by the amount of circulating-free DNA (cfDNA) input and stage of melanoma. At the recommended cfDNA input quantity of 20 ng (available in 28/74 patients), at least one cancer-associated mutation was detected in the ctDNA of 84% of stage IV patients and 47% of stage III patients with a limit of detection for mutant allele frequency (MAF) of 0.2%. This custom melanoma panel showed significant correlation with droplet digital PCR (ddPCR) and provided a more comprehensive melanoma mutation profile. Our custom panel could be further optimized by replacing amplicons spanning the promoter, which did not perform well due to the high GC content. To increase the detection rate to 90% of stage IV melanoma and decrease the sensitivity to 0.1% MAF, we recommend increasing the volume of plasma to 8 mL to achieve minimal recommended cfDNA input and the refinement of poorly performing amplicons. Our panel can also be expanded to include new targetable and treatment resistance mutations to improve the tracking of treatment response and resistance in melanoma patients treated with systemic drug therapies.
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http://dx.doi.org/10.3390/cancers12082228DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7465941PMC
August 2020

Reappraisal of the prognostic significance of mitotic rate supports its reincorporation into the melanoma staging system.

Cancer 2020 Nov 11;126(21):4717-4725. Epub 2020 Aug 11.

Melanoma Institute Australia, The University of Sydney, Sydney, New South Wales, Australia.

Background: Mitotic rate is a strong, independent prognostic factor in patients with melanoma. However, incorporating it into the melanoma staging system has proved challenging.

Methods: The prognostic impact of mitotic rate was assessed in a melanoma cohort comprising 5050 patients from 2 geographically distinct populations. Computer-generated cut points for mitotic rate were constructed to determine its impact on melanoma-associated survival using Kaplan-Meier and multivariate regression analyses. The impact of mitotic rate also was assessed in randomly split training and validation sets.

Results: Mitotic rate had a nonlinear impact on survival, as evidenced by unequally spaced cut points. An index incorporating these cut points that was constructed from one population produced significantly more accurate predictions of survival in the other population than using the entire scale of mitotic rate. An index constructed from the combined cohort was found to be independently predictive of survival, with an impact comparable to that of ulceration. Optimal high-versus-low cut points for mitotic rate were generated separately for each T category (<2 mitoses/mm vs ≥2 mitoses/mm for T1 melanoma, <4 mitoses/mm vs ≥4 mitoses/mm for T2 melanoma, <6 mitoses/mm vs ≥6/mitoses/mm for T3 melanoma, and <7 mitoses/mm vs ≥7 mitoses/mm for T4 melanoma). Using Kaplan-Meier analysis, elevated mitotic rate was found to have an impact on survival comparable to that of ulceration within each T category. Application of the index for mitotic rate that was constructed from the training data set demonstrated an independent impact in the validation data set, with a significance similar to that of ulceration.

Conclusions: The results of the current study demonstrated the comparable prognostic impact of mitotic rate and ulceration, providing support for its reincorporation into the T category.
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http://dx.doi.org/10.1002/cncr.33088DOI Listing
November 2020

Multiplex melanoma families are enriched for polygenic risk.

Hum Mol Genet 2020 Oct;29(17):2976-2985

Statistical Genetics, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia.

Cancers, including cutaneous melanoma, can cluster in families. In addition to environmental etiological factors such as ultraviolet radiation, cutaneous melanoma has a strong genetic component. Genetic risks for cutaneous melanoma range from rare, high-penetrance mutations to common, low-penetrance variants. Known high-penetrance mutations account for only about half of all densely affected cutaneous melanoma families, and the causes of familial clustering in the remainder are unknown. We hypothesize that some clustering is due to the cumulative effect of a large number of variants of individually small effect. Common, low-penetrance genetic risk variants can be combined into polygenic risk scores. We used a polygenic risk score for cutaneous melanoma to compare families without known high-penetrance mutations with unrelated melanoma cases and melanoma-free controls. Family members had significantly higher mean polygenic load for cutaneous melanoma than unrelated cases or melanoma-free healthy controls (Bonferroni-corrected t-test P = 1.5 × 10-5 and 6.3 × 10-45, respectively). Whole genome sequencing of germline DNA from 51 members of 21 families with low polygenic risk for melanoma identified a CDKN2A p.G101W mutation in a single family but no other candidate high-penetrance melanoma susceptibility genes. This work provides further evidence that melanoma, like many other common complex disorders, can arise from the joint action of multiple predisposing factors, including rare high-penetrance mutations, as well as via a combination of large numbers of alleles of small effect.
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http://dx.doi.org/10.1093/hmg/ddaa156DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7566496PMC
October 2020

Staging 18F-FDG PET/CT influences the treatment plan in melanoma patients with satellite or in-transit metastases.

Melanoma Res 2020 08;30(4):358-363

Melanoma Institute Australia, Sydney, Australia.

Whole-body positron emission tomography/computed tomography (PET/CT) and brain magnetic resonance imaging (MRI) are commonly used to stage patients with palpable lymph node metastases from melanoma, but their role in patients with satellite and/or in-transit metastasis (S&ITM) is unclear. The aim of this study was to establish the diagnostic value of PET/CT and brain MRI in these patients, and to assess their influence on subsequent management decisions. In this prospective study, 25 melanoma patients with a first presentation of S&ITM who had no clinical evidence of palpable nodal or distant metastasis underwent whole-body F-FDG PET/CT and brain MRI after a tentative pre-scan treatment plan had been made. Sensitivity and specificity of imaging were determined by pathological confirmation, clinical outcome and repeat PET/CT and MRI at 6 months. PET/CT led to a modification of the initial treatment plan in four patients (16%). All four were upstaged (AJCC stage eighth edition). PET/CT was false-positive in one patient, who had a Schwannoma in his trapezius muscle. A thyroid carcinoma was an incidental finding in another patient. The sensitivity of PET/CT was 58% and specificity 83%. In 6 months following the baseline PET/CT, further sites of in-transit or systemic disease were identified in 10 patients (40%). Brain MRI did not alter the treatment plan or change the disease stage in any patient. Whole-body PET/CT improved staging in melanoma patients with S&ITM and changed the originally-contemplated treatment plan in 16%. MRI of the brain appeared not to be useful.
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http://dx.doi.org/10.1097/CMR.0000000000000666DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7331822PMC
August 2020

Improved Risk Prediction Calculator for Sentinel Node Positivity in Patients With Melanoma: The Melanoma Institute Australia Nomogram.

J Clin Oncol 2020 08 12;38(24):2719-2727. Epub 2020 Jun 12.

Melanoma Institute Australia, The University of Sydney, North Sydney, New South Wales, Australia.

Purpose: For patients with primary cutaneous melanoma, the risk of sentinel node (SN) metastasis varies according to several clinicopathologic parameters. Patient selection for SN biopsy can be assisted by National Comprehensive Cancer Network (NCCN) and ASCO/Society of Surgical Oncology (SSO) guidelines and the Memorial Sloan Kettering Cancer Center (MSKCC) online nomogram. We sought to develop an improved online risk calculator using alternative clinicopathologic parameters to more accurately predict SN positivity.

Patients And Methods: Data from 3,477 patients with melanoma who underwent SN biopsy at Melanoma Institute Australia (MIA) were analyzed. A new nomogram was developed by replacing body site and Clark level from the MSKCC model with mitotic rate, melanoma subtype, and lymphovascular invasion. The predictive performance of the new nomogram was externally validated using data from The University of Texas MD Anderson Cancer Center (n = 3,496).

Results: The MSKCC model receiver operating characteristic curve had a predictive accuracy of 67.7% (95% CI, 65.3% to 70.0%). The MIA model had a predictive accuracy of 73.9% (95% CI, 71.9% to 75.9%), a 9.2% increase in accuracy over the MSKCC model ( < .001). Among the 2,748 SN-negative patients, SN biopsy would not have been offered to 22.1%, 13.4%, and 12.4% based on the MIA model, the MSKCC model, and NCCN or ASCO/SSO criteria, respectively. External validation generated a C-statistic of 75.0% (95% CI, 73.2% to 76.7%).

Conclusion: A robust nomogram was developed that more accurately estimates the risk of SN positivity in patients with melanoma than currently available methods. The model only requires the input of 6 widely available clinicopathologic parameters. Importantly, the number of patients undergoing unnecessary SN biopsy would be significantly reduced compared with use of the MSKCC nomogram or the NCCN or ASCO/SSO guidelines, without losing sensitivity. An online calculator is available at www.melanomarisk.org.au.
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http://dx.doi.org/10.1200/JCO.19.02362DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7430218PMC
August 2020

Transcriptional downregulation of MHC class I and melanoma de- differentiation in resistance to PD-1 inhibition.

Nat Commun 2020 04 20;11(1):1897. Epub 2020 Apr 20.

Macquarie University, Sydney, NSW, Australia.

Transcriptomic signatures designed to predict melanoma patient responses to PD-1 blockade have been reported but rarely validated. We now show that intra-patient heterogeneity of tumor responses to PD-1 inhibition limit the predictive performance of these signatures. We reasoned that resistance mechanisms will reflect the tumor microenvironment, and thus we examined PD-1 inhibitor resistance relative to T-cell activity in 94 melanoma tumors collected at baseline and at time of PD-1 inhibitor progression. Tumors were analyzed using RNA sequencing and flow cytometry, and validated functionally. These analyses confirm that major histocompatibility complex (MHC) class I downregulation is a hallmark of resistance to PD-1 inhibitors and is associated with the MITF/AXL de-differentiated phenotype and cancer-associated fibroblast signatures. We demonstrate that TGFß drives the treatment resistant phenotype (MITF/AXL) and contributes to MHC class I downregulation in melanoma. Combinations of anti-PD-1 with drugs that target the TGFß signaling pathway and/or which reverse melanoma de-differentiation may be effective future therapeutic strategies.
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http://dx.doi.org/10.1038/s41467-020-15726-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7171183PMC
April 2020

Close proximity of immune and tumor cells underlies response to anti-PD-1 based therapies in metastatic melanoma patients.

Oncoimmunology 2020 16;9(1):1659093. Epub 2019 Oct 16.

Melanoma Institute Australia, The University of Sydney, Sydney, Australia.

Immune checkpoint blockade has greatly improved the clinical outcomes of many patients with metastatic melanoma, however, almost half do not respond. Whether the interspatial distribution of immune and tumor cells predicts response to anti-PD-1-based therapies and patient outcomes in any cancer, including melanoma, is currently unknown. Here, we examined the spatial distribution of immune and tumor cells via multiplex immunofluorescence. Pre-treatment melanoma specimens from 27 patients ( = 18 responders; = 9 non-responders) treated with anti-PD-1 monotherapy and 34 patients ( = 22 responders; = 12 non-responders) treated with combined ipilimumab and anti-PD-1 immunotherapy were studied. Responders displayed significantly higher densities of CD8 tumor-infiltrating lymphocytes within a 20 µM distance from a melanoma cell compared to non-responders in both anti-PD-1 alone ( = .0024) and combination-treated patients ( = .0096), that were associated with improved progression-free survival for both therapies (anti-PD-1 = .0158; combination therapy = .0088). In multivariate analysis, the best model for 12-month progression-free survival for anti-PD-1 monotherapy included PD-L1 cells within proximity to tumor cells and intratumoral CD8 density (AUC = 0.80), and for combination therapy included CD8 cells in proximity to tumor cells, intratumoral PD-L1 density and LDH (AUC = 0.85). Assessment of the spatial distribution of immune cells in relation to tumor cells provides insight into their role in modulating immune response and highlights their potential role as predictors of response to anti-PD-1 based therapies.
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http://dx.doi.org/10.1080/2162402X.2019.1659093DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6959449PMC
October 2019

Cumulative Incidence and Predictors of CNS Metastasis for Patients With American Joint Committee on Cancer 8th Edition Stage III Melanoma.

J Clin Oncol 2020 05 28;38(13):1429-1441. Epub 2020 Jan 28.

Department of Melanoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX.

Purpose: Improved understanding of the incidence, risk factors, and timing of CNS metastasis is needed to inform surveillance strategies for patients with melanoma.

Patients And Methods: Clinical data were extracted from the databases of 2 major melanoma centers in the United States and Australia for 1,918 patients with American Joint Committee on Cancer (AJCC) 8th edition stage III melanoma, diagnosed from 1998-2014, who had (negative) baseline CNS imaging within 4 months of diagnosis. The cumulative incidence of CNS metastasis was calculated in the presence of the competing risk of death, from stage III presentation and at benchmark time points 1, 2, and 5 years postdiagnosis.

Results: At a median follow-up of 70.2 months, distant recurrence occurred in 711 patients (37.1%). The first site of distant metastasis was CNS only for 3.9% of patients, CNS and extracranial (EC) for 1.8%, and EC only for 31.4%. Overall, 16.7% of patients were diagnosed with CNS metastasis during follow-up. The cumulative incidence of CNS metastasis was 3.6% (95% CI, 2.9% to 4.6%) at 1 year, 9.6% (95% CI, 8.3% to 11.0%) at 2 years, and 15.8% (95% CI, 14.1% to 17.6%) at 5 years. The risk of CNS metastasis was significantly influenced by patient sex, age, AJCC stage, primary tumor site, and primary tumor mitotic rate in multivariable and conditional analyses. High primary tumor mitotic rate was significantly associated with increased risk of CNS metastasis at diagnosis and all subsequent time points examined.

Conclusion: Similar rates of CNS metastasis were observed in 2 large, geographically distinct cohorts of patients with stage III melanoma. The results highlight the importance of primary tumor mitotic rate. Furthermore, they provide a framework for developing evidence-based surveillance strategies and evaluating the impact of contemporary adjuvant therapies on the risk of CNS metastasis development.
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http://dx.doi.org/10.1200/JCO.19.01508DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7193747PMC
May 2020

Analysis of the Whole-Exome Sequencing of Tumor and Circulating Tumor DNA in Metastatic Melanoma.

Cancers (Basel) 2019 Nov 29;11(12). Epub 2019 Nov 29.

Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW 2109, Australia.

The use of circulating tumor DNA (ctDNA) to monitor cancer progression and response to therapy has significant potential but there is only limited data on whether this technique can detect the presence of low frequency subclones that may ultimately confer therapy resistance. In this study, we sought to evaluate whether whole-exome sequencing (WES) of ctDNA could accurately profile the mutation landscape of metastatic melanoma. We used WES to identify variants in matched, tumor-derived genomic DNA (gDNA) and plasma-derived ctDNA isolated from a cohort of 10 metastatic cutaneous melanoma patients. WES parameters such as sequencing coverage and total sequencing reads were comparable between gDNA and ctDNA. The mutant allele frequency of common single nucleotide variants was lower in ctDNA, reflecting the lower read depth and minor fraction of ctDNA within the total circulating free DNA pool. There was also variable concordance between gDNA and ctDNA based on the total number and identity of detected variants and this was independent of the tumor biopsy site. Nevertheless, established melanoma driver mutations and several other melanoma-associated mutations were concordant between matched gDNA and ctDNA. This study highlights that WES of ctDNA could capture clinically relevant mutations present in melanoma metastases and that enhanced sequencing sensitivity will be required to identify low frequency mutations.
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http://dx.doi.org/10.3390/cancers11121905DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6966626PMC
November 2019

Current management of patients with melanoma who are found to be sentinel node-positive.

ANZ J Surg 2020 04 30;90(4):491-496. Epub 2019 Oct 30.

Melanoma Institute Australia, The University of Sydney, Sydney, New South Wales, Australia.

Background: The results of the DeCOG-SLT and MSLT-II studies, published in 2016 and mid-2017, indicated no survival benefit from completion lymph node dissection (CLND) in melanoma patients with positive sentinel nodes (SNs). Subsequently, several studies have been published reporting a benefit of adjuvant systemic therapy in patients with stage III melanoma. The current study assessed how these findings influenced management of SN-positive patients in a dedicated melanoma treatment centre.

Methods: SN-positive patients treated at Melanoma Institute Australia between July 2017 and December 2018 were prospectively identified. Surgeons completed a questionnaire documenting the management of each patient. Information on patients, primary tumours, SNs, further treatment and follow-up was collected from patient files, the institutional research database and pathology reports.

Results: During the 18-month study period, 483 patients underwent SN biopsy. A positive SN was found in 61 (13%). Two patients (3%) requested CLND because of anxiety about observation in view of unfavourable primary tumour and SN characteristics. The other 59 patients (97%) were followed with a four-monthly ultrasound examination of the relevant lymph node field(s). Two of them (3%) developed an isolated nodal recurrence after 4 and 11 months of follow-up. Fifty-seven patients (93%) were seen following the publication of the first two adjuvant systemic therapy studies in November 2017; 46 (81%) were referred to a medical oncologist to discuss adjuvant systemic therapy, which 32 (70%) chose to receive.

Conclusion: At Melanoma Institute Australia most patients with an involved SN are now managed without CLND. The majority are referred to a medical oncologist and receive adjuvant systemic therapy.
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http://dx.doi.org/10.1111/ans.15491DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7216885PMC
April 2020

Whole-genome landscape of mucosal melanoma reveals diverse drivers and therapeutic targets.

Nat Commun 2019 07 18;10(1):3163. Epub 2019 Jul 18.

Melanoma Institute Australia, The University of Sydney, Sydney, NSW, 2065, Australia.

Knowledge of key drivers and therapeutic targets in mucosal melanoma is limited due to the paucity of comprehensive mutation data on this rare tumor type. To better understand the genomic landscape of mucosal melanoma, here we describe whole genome sequencing analysis of 67 tumors and validation of driver gene mutations by exome sequencing of 45 tumors. Tumors have a low point mutation burden and high numbers of structural variants, including recurrent structural rearrangements targeting TERT, CDK4 and MDM2. Significantly mutated genes are NRAS, BRAF, NF1, KIT, SF3B1, TP53, SPRED1, ATRX, HLA-A and CHD8. SF3B1 mutations occur more commonly in female genital and anorectal melanomas and CTNNB1 mutations implicate a role for WNT signaling defects in the genesis of some mucosal melanomas. TERT aberrations and ATRX mutations are associated with alterations in telomere length. Mutation profiles of the majority of mucosal melanomas suggest potential susceptibility to CDK4/6 and/or MEK inhibitors.
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http://dx.doi.org/10.1038/s41467-019-11107-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6639323PMC
July 2019

Neoadjuvant systemic therapy in melanoma: recommendations of the International Neoadjuvant Melanoma Consortium.

Lancet Oncol 2019 07;20(7):e378-e389

Melanoma Institute of Australia, The University of Sydney, Sydney, NSW, Australia; Department of Medical Oncology, Royal North Shore Hospital, Sydney, NSW, Australia; Department of Medical Oncology, Mater Hospital Sydney, Sydney, NSW, Australia. Electronic address:

Advances in the treatment of metastatic melanoma have improved responses and survival. However, many patients continue to experience resistance or toxicity to treatment, highlighting a crucial need to identify biomarkers and understand mechanisms of response and toxicity. Neoadjuvant therapy for regional metastases might improve operability and clinical outcomes over upfront surgery and adjuvant therapy, and has become an established role for drug development and biomarker discovery in other cancers (including locally advanced breast cancer, head and neck squamous cell carcinomas, gastroesophageal cancer, and anal cancer). Patients with clinically detectable stage III melanoma are ideal candidates for neoadjuvant therapy, because they represent a high-risk patient population with poor outcomes when treated with upfront surgery alone. Neoadjuvant therapy is now an active area of research for melanoma with numerous completed and ongoing trials (since 2014) with disparate designs, endpoints, and analyses under investigation. We have, therefore, established the International Neoadjuvant Melanoma Consortium with experts in medical oncology, surgical oncology, pathology, radiation oncology, radiology, and translational research to develop recommendations for investigating neoadjuvant therapy in melanoma to align future trial designs and correlative analyses. Alignment and consistency of neoadjuvant trials will facilitate optimal data organisation for future regulatory review and strengthen translational research across the melanoma disease continuum.
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http://dx.doi.org/10.1016/S1470-2045(19)30332-8DOI Listing
July 2019

Neoadjuvant dabrafenib combined with trametinib for resectable, stage IIIB-C, BRAF mutation-positive melanoma (NeoCombi): a single-arm, open-label, single-centre, phase 2 trial.

Lancet Oncol 2019 07 3;20(7):961-971. Epub 2019 Jun 3.

Melanoma Institute Australia, The University of Sydney, Sydney, NSW, Australia; Royal North Shore Hospital, St Leonards, Sydney, NSW, Australia.

Background: Adjuvant dabrafenib plus trametinib therapy improves relapse-free survival in patients with resected stage III melanoma. We aimed to ascertain the proportion of patients who would have a pathological response and a response according to Response Evaluation Criteria in Solid Tumors (RECIST) after neoadjuvant dabrafenib plus trametinib therapy for resectable clinical stage III melanoma.

Methods: NeoCombi was a single-arm, open-label, single-centre, phase 2 study done at Melanoma Institute Australia (Sydney, NSW, Australia). Eligible patients were adults (aged ≥18 years) with histologically confirmed, resectable, RECIST-measurable, clinical stage IIIB-C (American Joint Committee on Cancer [AJCC] 7th edition), BRAF-mutant melanoma, and had an Eastern Cooperative Oncology Group performance status of 1 or lower. Patients received 150 mg dabrafenib orally, twice daily, plus 2 mg trametinib orally, once daily, for 52 weeks (12 weeks of neoadjuvant therapy before complete resection of the pre-therapy tumour bed, and 40 weeks of adjuvant therapy thereafter). CT and PET scans were done at baseline and before resection. The primary outcomes were the proportion of patients achieving a complete pathological response and the proportion of patients achieving a response according to RECIST at week 12, analysed as per protocol. This trial is registered with ClinicalTrials.gov, NCT01972347, and follow-up of patients is ongoing.

Findings: Between Aug 20, 2014, and April 19, 2017, 40 patients were screened, of whom 35 eligible patients were enrolled, received neoadjuvant dabrafenib plus trametinib, and underwent resection. At the data cutoff (Sept 24, 2018), median follow-up was 27 months (IQR 21-36). At resection, 30 (86%) patients achieved a RECIST response; 16 (46%; 95% CI 29-63) had a complete response and 14 (40%; 24-58) had a partial response. Five patients (14%; 95% CI 5-30) had stable disease, and no patients progressed. After resection and pathological evaluation, all 35 patients achieved a pathological response, of whom 17 (49%; 95% CI 31-66) patients had a complete pathological response and 18 (51%; 95% CI 34-69) had a non-complete pathological response. Treatment-related serious adverse events occurred in six (17%) of 35 patients and grade 3-4 adverse events occurred in ten (29%) patients. No treatment-related deaths were reported.

Interpretation: Neoadjuvant dabrafenib plus trametinib therapy could be considered in the management of RECIST-measurable resectable stage III melanoma as it led to a high proportion of patients achieving a complete response according to RECIST and a high proportion of patients achieving a complete pathological response, with no progression during neoadjuvant therapy.

Funding: GlaxoSmithKline; Novartis; National Health and Medical Research Council, Australia; and Melanoma Institute Australia.
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http://dx.doi.org/10.1016/S1470-2045(19)30331-6DOI Listing
July 2019

Identification of the optimal combination dosing schedule of neoadjuvant ipilimumab plus nivolumab in macroscopic stage III melanoma (OpACIN-neo): a multicentre, phase 2, randomised, controlled trial.

Lancet Oncol 2019 07 31;20(7):948-960. Epub 2019 May 31.

The Netherlands Cancer Institute, Amsterdam, Netherlands. Electronic address:

Background: The outcome of patients with macroscopic stage III melanoma is poor. Neoadjuvant treatment with ipilimumab plus nivolumab at the standard dosing schedule induced pathological responses in a high proportion of patients in two small independent early-phase trials, and no patients with a pathological response have relapsed after a median follow up of 32 months. However, toxicity of the standard ipilimumab plus nivolumab dosing schedule was high, preventing its broader clinical use. The aim of the OpACIN-neo trial was to identify a dosing schedule of ipilimumab plus nivolumab that is less toxic but equally effective.

Methods: OpACIN-neo is a multicentre, open-label, phase 2, randomised, controlled trial. Eligible patients were aged at least 18 years, had a WHO performance status of 0-1, had resectable stage III melanoma involving lymph nodes only, and measurable disease according to the Response Evaluation Criteria in Solid Tumors version 1.1. Patients were enrolled from three medical centres in Australia, Sweden, and the Netherlands, and were randomly assigned (1:1:1), stratified by site, to one of three neoadjuvant dosing schedules: group A, two cycles of ipilimumab 3 mg/kg plus nivolumab 1 mg/kg once every 3 weeks intravenously; group B, two cycles of ipilimumab 1 mg/kg plus nivolumab 3 mg/kg once every 3 weeks intravenously; or group C, two cycles of ipilimumab 3 mg/kg once every 3 weeks directly followed by two cycles of nivolumab 3 mg/kg once every 2 weeks intravenously. The investigators, site staff, and patients were aware of the treatment assignment during the study participation. Pathologists were masked to treatment allocation and all other data. The primary endpoints were the proportion of patients with grade 3-4 immune-related toxicity within the first 12 weeks and the proportion of patients achieving a radiological objective response and pathological response at 6 weeks. Analyses were done in all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, number NCT02977052, and is ongoing with an additional extension cohort and to complete survival analysis.

Findings: Between Nov 24, 2016 and June 28, 2018, 105 patients were screened for eligibility, of whom 89 (85%) eligible patients were enrolled and randomly assigned to one of the three groups. Three patients were excluded after randomisation because they were found to be ineligible, and 86 received at least one dose of study drug; 30 patients in group A, 30 in group B, and 26 in group C (accrual to this group was closed early upon advice of the Data Safety Monitoring Board on June 4, 2018 because of severe adverse events). Within the first 12 weeks, grade 3-4 immune-related adverse events were observed in 12 (40%) of 30 patients in group A, six (20%) of 30 in group B, and 13 (50%) of 26 in group C. The difference in grade 3-4 toxicity between group B and A was -20% (95% CI -46 to 6; p=0·158) and between group C and group A was 10% (-20 to 40; p=0·591). The most common grade 3-4 adverse events were elevated liver enzymes in group A (six [20%)]) and colitis in group C (five [19%]); in group B, none of the grade 3-4 adverse events were seen in more than one patient. One patient (in group A) died 9·5 months after the start of treatment due to the consequences of late-onset immune-related encephalitis, which was possibly treatment-related. 19 (63% [95% CI 44-80]) of 30 patients in group A, 17 (57% [37-75]) of 30 in group B, and nine (35% [17-56]) of 26 in group C achieved a radiological objective response, while pathological responses occurred in 24 (80% [61-92]) patients in group A, 23 (77% [58-90]) in group B, and 17 (65% [44-83]) in group C.

Interpretation: OpACIN-neo identified a tolerable neoadjuvant dosing schedule (group B: two cycles of ipilimumab 1 mg/kg plus nivolumab 3 mg/kg) that induces a pathological response in a high proportion of patients and might be suitable for broader clinical use. When more mature data confirm these early observations, this schedule should be tested in randomised phase 3 studies versus adjuvant therapies, which are the current standard-of-care systemic therapy for patients with stage III melanoma.

Funding: Bristol-Myers Squibb.
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http://dx.doi.org/10.1016/S1470-2045(19)30151-2DOI Listing
July 2019

False-Positive Results and Incidental Findings with Annual CT or PET/CT Surveillance in Asymptomatic Patients with Resected Stage III Melanoma.

Ann Surg Oncol 2019 Jun 25;26(6):1860-1868. Epub 2019 Mar 25.

Melanoma Institute Australia, The University of Sydney, Sydney, NSW, Australia.

Objective: The aim of this study was to quantify false-positive and incidental findings from annual surveillance imaging in asymptomatic, American Joint Committee on Cancer stage III melanoma patients.

Methods: This was a cohort study of patients treated at Melanoma Institute Australia (2000-2015) with baseline computed tomography (CT) or positron emission tomography (PET)/CT imaging and at least two annual surveillance scans. False-positives were defined as findings suspicious for melanoma recurrence that were not melanoma, confirmed by histopathology, subsequent imaging, or clinical follow-up, while incidental findings were defined as non-melanoma-related findings requiring further action. Outcomes of incidental findings were classified as 'benign' if they resolved spontaneously or were not seriously harmful; 'malignant' if a second malignancy was identified; or 'other' if potentially harmful.

Results: Among 154 patients, 1022 scans were performed (154 baseline staging, 868 surveillance) during a median follow-up of 85 months (interquartile range 56-112); 57 patients (37%) developed a recurrence. For baseline and surveillance imaging, 124 false-positive results and incidental findings were identified in 81 patients (53%). The frequency of these findings was 5-14% per year, and an additional 181 tests, procedures, and referrals were initiated to investigate these findings. The diagnosis was benign in 109 findings of 124 findings (88%). Fifteen patients with a benign finding underwent an unnecessary invasive procedure. Surveillance imaging identified distant metastases in 20 patients (13%).

Conclusion: False-positive results and incidental findings occur in at least half of all patients undergoing annual surveillance imaging, and the additional healthcare use is substantial. These findings persist over time. Clinicians need to be aware of these risks and discuss them with patients, alongside the expected benefits of surveillance imaging.
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http://dx.doi.org/10.1245/s10434-019-07311-0DOI Listing
June 2019

Recurrent hotspot SF3B1 mutations at codon 625 in vulvovaginal mucosal melanoma identified in a study of 27 Australian mucosal melanomas.

Oncotarget 2019 Jan 29;10(9):930-941. Epub 2019 Jan 29.

Melanoma Institute Australia, The University of Sydney, Sydney, Australia.

Introduction: Clinical outcomes for mucosal melanomas are often poor due to a lack of effective systemic drug therapies. Identifying driver genes in mucosal melanoma may enhance the understanding of disease pathogenesis and provide novel opportunities to develop effective therapies.

Results: Somatic variant analysis identified (6 of 27: 22%) as the most commonly mutated gene, followed by (3 of 27: 11%). Other less frequently mutated genes (4% otherwise stated) included (7%), (7%), , , , , , , and . Recurrent SF3B1 p.R625 hotspot mutations were exclusively detected in vulvovaginal (5 of 19: 26%) and anorectal melanomas (3 of 5:60%). The only other SF3B1 mutation was a p.C1123Y mutation that occurred in a conjunctival mucosal melanoma.-mutated patients were associated with shorter overall survival (OS; 34.9 months) and progression-free survival (PFS; 16.9 months) compared to non--mutated patients (OS: 79.7 months, log-rank = 0.1172; PFS: 35.7 months, log-rank = 0.0963).

Conclusion: Molecular subgroups of mucosal melanoma with mutations occurred predominantly in the vulvovaginal region. mutations may have a negative prognostic impact.

Methods: Formalin-fixed biopsies were collected from 27 pathologically-confirmed mucosal melanomas. Genomic DNA was isolated from the tumor tissue and sequenced using a novel dual-strand amplicon sequencing technique to determine the frequency and types of mutations across 45 target genes.
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http://dx.doi.org/10.18632/oncotarget.26584DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6398173PMC
January 2019

Prevalence and Cellular Distribution of Novel Immune Checkpoint Targets Across Longitudinal Specimens in Treatment-naïve Melanoma Patients: Implications for Clinical Trials.

Clin Cancer Res 2019 06 18;25(11):3247-3258. Epub 2019 Feb 18.

Melanoma Institute Australia, The University of Sydney, North Sydney, New South Wales, Australia.

Purpose: Immunotherapies targeting costimulating and coinhibitory checkpoint receptors beyond PD-1 and CTLA-4 have entered clinical trials. Little is known about the relative abundance, coexpression, and immune cells enriched for each specific drug target, limiting understanding of the biological basis of potential treatment outcomes and development of predictive biomarkers for personalized immunotherapy. We sought to assess the abundance of checkpoint receptors during melanoma disease progression and identify immune cells enriched for them. Multiplex immunofluorescence staining for immune checkpoint receptors (ICOS, GITR, OX40, PD-1, TIM-3, VISTA) was performed on 96 melanoma biopsies from 41 treatment-naïve patients, including patient-matched primary tumors, nodal metastases, and distant metastases. Mass cytometry was conducted on tumor dissociates from 18 treatment-naïve melanoma metastases to explore immune subsets enriched for checkpoint receptors.

Results: A small subset of tumor-infiltrating leukocytes expressed checkpoint receptors at any stage of melanoma disease. GITR and OX40 were the least abundant checkpoint receptors, with <1% of intratumoral T cells expressing either marker. ICOS, PD-1, TIM-3, and VISTA were most abundant, with TIM-3 and VISTA mostly expressed on non-T cells, and TIM-3 enriched on dendritic cells. Tumor-resident T cells (CD69/CD103/CD8) were enriched for TIGIT (>70%) and other coinhibitory but not costimulatory receptors. The proportion of GITR T cells decreased from primary melanoma (>5%) to lymph node (<1%, = 0.04) and distant metastases (<1%, = 0.0005).

Conclusions: This study provides the first comprehensive assessment of immune checkpoint receptor expression in any cancer and provides important data for rational selection of targets for trials and predictive biomarker development.
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http://dx.doi.org/10.1158/1078-0432.CCR-18-4011DOI Listing
June 2019

Molecular Genomic Profiling of Melanocytic Nevi.

J Invest Dermatol 2019 08 14;139(8):1762-1768. Epub 2019 Feb 14.

Melanoma Institute Australia, The University of Sydney, New South Wales, Australia; Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia.

The benign melanocytic nevus is the most common tumor in humans and rarely transforms into cutaneous melanoma. Elucidation of the nevus genome is required to better understand the molecular steps of progression to melanoma. We performed whole genome sequencing on a series of 14 benign melanocytic nevi consisting of both congenital and acquired types. All nevi had driver mutations in the MAPK signaling pathway, either BRAF V600E or NRAS Q61R/L. No additional definite driver mutations were identified. Somatic mutations in nevi with higher mutation loads showed a predominance of mutational signatures 7a and 7b, consistent with UVR exposure, whereas nevi with lower mutation loads (including all three congenital nevi) had a predominance of the ubiquitous signatures 1 and 5. Two nevi had mutations in promoter regions predicted to bind E26 transformation-specific family transcription factors, as well as subclonal mutations in the TERT promoter. This paper presents whole genome data from melanocytic nevi. We confirm that UVR is involved in the etiology of a subset of nevi. This study also establishes that TERT promoter mutations are present in morphologically benign skin nevi in subclonal populations, which has implications regarding the interpretation of this emerging biomarker in sensitive assays.
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http://dx.doi.org/10.1016/j.jid.2018.12.033DOI Listing
August 2019

Distinct Immune Cell Populations Define Response to Anti-PD-1 Monotherapy and Anti-PD-1/Anti-CTLA-4 Combined Therapy.

Cancer Cell 2019 02;35(2):238-255.e6

Melanoma Institute Australia, The University of Sydney, Sydney, NSW 2065, Australia; Sydney Medical School, The University of Sydney, Sydney, NSW 2006, Australia. Electronic address:

Cancer immunotherapies provide survival benefits in responding patients, but many patients fail to respond. Identifying the biology of treatment response and resistance are a priority to optimize drug selection and improve patient outcomes. We performed transcriptomic and immune profiling on 158 tumor biopsies from melanoma patients treated with anti-PD-1 monotherapy (n = 63) or combined anti-PD-1 and anti-CTLA-4 (n = 57). These data identified activated T cell signatures and T cell populations in responders to both treatments. Further mass cytometry analysis identified an EOMESCD69CD45RO effector memory T cell phenotype that was significantly more abundant in responders to combined immunotherapy compared with non-responders (n = 18). The gene expression profile of this population was associated with longer progression-free survival in patients treated with single agent and greater tumor shrinkage in both treatments.
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http://dx.doi.org/10.1016/j.ccell.2019.01.003DOI Listing
February 2019

Integrated molecular and immunophenotypic analysis of NK cells in anti-PD-1 treated metastatic melanoma patients.

Oncoimmunology 2019;8(2):e1537581. Epub 2018 Oct 31.

Melanoma Institute Australia, The University of Sydney, Sydney, NSW, Australia.

: Anti-PD-1 therapy has revolutionized the treatment and improved the survival of stage IV melanoma patients. However, almost half of the patients fail to respond due to immune evasive mechanism. A known mechanism is the downregulation of major histocompatibility complex (MHC) class I expression, which prevents T cell recognition of the tumor. This study determined the relationship between natural killer (NK) cell numbers and clinical response to anti-PD-1 therapy in metastatic melanoma. : Twenty-five anti-PD-1 treated metastatic melanoma patients were categorized into responders (complete response (CR)/partial response (PR)/stable disease (SD) ≥ 6 mo, n = 13) and non-responders (SD < 6 days/progressive disease (PD), n = 12) based on RECIST response. Whole transcriptome sequencing and multiplex immunofluorescent staining were performed on pre-treatment and on a subset of early during treatment tumor samples. Spatial distribution analysis was performed on multiplex immunofluorescent images to determine the proximity of NK cells to tumor cells. Flow cytometry was used to confirm NK phenotypes in lymph node metastases of treatment naïve melanoma patients (n = 5). Cytotoxic assay was performed using NK cells treated with anti-PD-1 or with isotype control and co-cultured with 3 different melanoma cell lines and with K562 cells (leukemia cell line). : Differential expression analysis identified nine upregulated NK cell specific genes (adjusted p < 0.05) in responding (n = 11) versus non-responding patients (n = 10). Immunofluorescent staining of biopsies confirmed a significantly higher density of intra- and peri-tumoral CD16+ and granzyme B + NK cells in responding patients (< 0.05). Interestingly, NK cells were in closer proximity to tumor cells in responding PD-1 treated patients compared to non-responding patients. Patients who responded to anti-PD-1 therapy, despite MHC class I loss had higher NK cell densities than patients with low MHC class I expression. Lastly, functional assays demonstrated PD-1 blockade induces an increase in NK cells' cytotoxicity. : A higher density of tumoral NK cells is associated with response to anti-PD-1 therapy. NK cells may play an important role in mediating response to anti-PD-1 therapy, including in a subset of tumors downregulating MHC class I expression.
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http://dx.doi.org/10.1080/2162402X.2018.1537581DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6343795PMC
October 2018

Inter- and intrapatient heterogeneity of indoleamine 2,3-dioxygenase expression in primary and metastatic melanoma cells and the tumour microenvironment.

Histopathology 2019 May;74(6):817-828

Melanoma Institute Australia, The University of Sydney, Sydney, Australia.

Aims: Indoleamine 2,3-dioxygenase (IDO), an immunomodulatory enzyme, facilitates immune escape by tumours and promotes tumour progression. IDO inhibitors with and without additional anti-PD-1 therapy have been evaluated in recent and ongoing melanoma clinical trials, but IDO expression in melanoma tumours, and therefore its potential role as a predictive biomarker remains unknown. This study sought to evaluate IDO expression in immunotherapy-naive metastatic melanoma patients in order to determine patterns of expression in corresponding primary melanomas, locoregional metastases and distant metastases.

Methods And Results: Here, we evaluated IDO expression using immunohistochemistry in 99 melanoma tumour samples from 43 immunotherapy-naive patients with metastatic melanoma to determine patterns of expression in primary melanomas (n = 29), locoregional metastases (n = 36) and distant metastases (n = 34). Thirty-seven per cent of patients demonstrated tumour IDO expression in at least one specimen. Twelve of 35 patients (34%) with longitudinal specimens (i.e. two or more separate specimens from different disease stages in the same patient) displayed heterogeneous IDO staining between samples. Tumour IDO expression positively correlated with tumour-infiltrating lymphocyte (TIL) score as well as the number of IDO-expressing mononuclear cells in the primary melanoma (P < 0.0001 and P = 0.0011, respectively) and nodal metastases (P = 0.049 and P = 0.037, respectively), but not in distant metastases. Furthermore, tumour IDO expression correlated positively with PD-L1 expression by melanoma cells among all specimens (P = 0.0073).

Conclusions: Therefore, while assessment of tumour IDO expression warrants evaluation in melanoma patient cohorts treated with IDO inhibitors dosed at levels proven to inhibit the target by pharmacodynamic assessment, its utility as a biomarker may be limited by intertumoral heterogeneity.
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http://dx.doi.org/10.1111/his.13814DOI Listing
May 2019

Subungual Melanoma of the Hand.

Ann Surg Oncol 2019 Apr 18;26(4):1035-1043. Epub 2018 Dec 18.

Melanoma Institute Australia, Sydney, NSW, Australia.

Background: The diagnosis of subungual melanoma (SUM) can be challenging and SUMs generally have a worse prognosis than melanomas arising elsewhere. Due to their rarity, the evidence to guide management is limited. This study sought to identify clinicopathological features predictive of outcome and to provide guidelines for management.

Methods: From a large, single-institution database, 103 patients with in situ (n = 9) or invasive (n = 94) SUMs of the hand treated between 1953 and 2014 were identified and their features analyzed.

Results: The most common site of hand SUMs was the thumb (53%). Median tumor thickness was 3.1 mm, and SUMs were commonly of the acral subtype (57%), ulcerated (58%), amelanotic (32%), and had mitoses (73%). Twenty-one patients reported prior trauma to the tumor site. Twenty-two patients were stage III at diagnosis; 7 underwent therapeutic lymph node dissection and 22 underwent elective lymph node dissection (5 positive), while 36 had sentinel node biopsy (SNB), 28% of which were positive. Forty percent of SNB-positive patients had involved non-sentinel nodes (SNs) in their completion lymph node dissection. Five-year melanoma-specific survival (MSS) and disease-free survival (DFS) rates were 70% and 52%, respectively. On multivariate analysis, regional node metastasis and right-hand tumor location were significant predictors of shorter DFS and MSS, whereas mitoses negatively impacted DFS only and increasing Breslow thickness impacted MSS only.

Conclusions: This study confirms that SUMs on the hand usually present at an advanced stage. Distal amputation appears safe for invasive SUMs, and SNB should be considered as these patients have a high risk of both SN and non-SN metastasis.
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http://dx.doi.org/10.1245/s10434-018-07094-wDOI Listing
April 2019

Correlation Between Surgical and Histologic Margins in Melanoma Wide Excision Specimens.

Ann Surg Oncol 2019 Jan 16;26(1):25-32. Epub 2018 Oct 16.

Melanoma Institute Australia, The University of Sydney, North Sydney, NSW, Australia.

Introduction: Wide surgical excision is the standard treatment for localized primary cutaneous melanomas, with a narrow histologic margin associated with an increased risk of local recurrence. The correlation between surgical and histologic margins is poorly documented in the literature.

Methods: An audit was performed to (1) document the shrinkage of formalin-fixed specimens, and (2) use a precisely measured surgical margin in vivo to predict the histologic margin. For patients presenting for wide excision of melanomas and other malignant skin tumors, measured surgical margin, in vivo and ex vivo specimen width, and histologic margins after formalin fixation were recorded. The effects of clinicopathologic characteristics, including age, sex, body mass index (BMI), tumor type, anatomic site, and presence of visible tumor in predicting specimen shrinkage and histologic margin were assessed.

Results: In total, 252 specimens were evaluated. When compared with measured width in vivo, the formalin-fixed specimens showed a mean shrinkage of 14% (R = 0.98), regardless of patient age, sex, BMI, or site of the lesion. The measured surgical margin was not a strong predictor of the histologic margin, with a high degree of variability (R = 0.55) not explained by patient factors, tumor subtype, or presence of visible tumor at the time of excision (p > 0.05).

Conclusions: A consistent 14% shrinkage rate of wide excision specimens was found across all patients and excision sites, and we propose a clinically useful 15% correction factor that will account for fixation and shrinkage of cutaneous excision specimens. Excision margins measured by the surgeon were a poor predictor of the histologic margins.
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http://dx.doi.org/10.1245/s10434-018-6858-yDOI Listing
January 2019