Publications by authors named "Chi Young Ok"

61 Publications

EZH2 expression is associated with inferior overall survival in mantle cell lymphoma.

Mod Pathol 2021 Aug 10. Epub 2021 Aug 10.

Department of Hematopathology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA.

Enhancer of zeste homolog 2 (EZH2) is a catalytic component of the polycomb repressive complex 2 (PRC2) which reduces gene expression via trimethylation of a lysine residue of histone 3 (H3K27me3). Expression of EZH2 has not been assessed systematically in mantle cell lymphoma (MCL). Expression of EZH2 was assessed by immunohistochemistry in 166 patients with MCL. We also assessed other PRC2 components and H3K27me3. Fifty-seven (38%) of MCL patients were positive for EZH2 using 40% cutoff. EZH2 expression was associated with aggressive histologic variants (65% vs. 29%, p < 0.001), high Ki-67 proliferation rate (median, 72% vs. 19%, p < 0.001), and p53 overexpression (43% vs. 2%, p < 0.001). EZH2 expression did not correlate with expression of other PRC2 components (EED and SUZ12), H3K27me3, MHC-I, and MHC-II. Patients with EZH2 expression (EZH2+) had a poorer overall survival (OS) compared with patients without EZH2 expression (EZH2-) (median OS: 3.9 years versus 9.4 years, respectively, p < 0.001). EZH2 expression also predicted a poorer prognosis in MCL patients with classic histology (median OS, 4.6 years for EZH2+ and 9.6 years for EZH2-negative, respectively, p < 0.001) as well as aggressive histology (median OS, 3.7 years for EZH2+ and 7.9 years for EZH2-negative, respectively, p = 0.046). However, EZH2 expression did not independently correlate with overall survival in a multivariate analysis. Gene expression analysis and pathway enrichment analysis demonstrated a significant enrichment in cell cycle and mitotic transition pathways in MCL with EZH2 expression. EZH2 expression detected by immunohistochemistry is present in 38% of MCL cases and it is associated with high proliferation rate, p53 overexpression, aggressive histologic variants, and poorer OS. Based on gene expression profiling data, EZH2 expression could potentiate cell cycle machinery in MCL. These data suggest that assessment of EZH2 expression could be useful to stratify MCL patients into low- and high-risk groups.
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http://dx.doi.org/10.1038/s41379-021-00885-9DOI Listing
August 2021

Breast implant-associated anaplastic large cell lymphoma: clinical follow-up and analysis of sequential pathologic specimens of untreated patients shows persistent or progressive disease.

Mod Pathol 2021 Jun 21. Epub 2021 Jun 21.

Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.

Breast implant-associated anaplastic large cell lymphoma (ALCL) is a distinctive type of T-cell lymphoma that arises around textured-surface breast implants. In a subset of patients, this disease can involve surrounding tissues, spread to regional lymph nodes, and rarely metastasize to distant sites. The aim of this study was to assess sequential pathologic specimens from patients with breast implant-associated ALCL to better understand the natural history of early-stage disease. To achieve this goal, we searched our files for patients who had breast implant-associated ALCL and who had undergone earlier surgical intervention with assessment of biopsy or cytologic specimens. We then focused on the patient subset in whom a definitive diagnosis was not established, and patients did not receive current standard-of-care therapy at that time. We identified a study group of ten patients with breast implant-associated ALCL in whom pathologic specimens were collected 0.5 to 4 years before a definitive diagnosis was established. A comparison of these serial biopsy specimens showed persistent disease without change in pathologic stage in three patients, progression in five patients, and persistence versus progression in two patients. Eventually, six patients underwent implant removal with complete capsulectomy and four underwent partial capsulectomy. Seven patients also received chemotherapy because of invasive disease, three of whom also received radiation therapy, two brentuximab vedotin after chemotherapy failure, and one allogeneic stem cell transplant. Eight patients achieved complete remission and two had partial remission after definitive therapy. At time of last follow-up, six patients were alive without disease, one had evidence of disease, one died of disease, and two patients died of unrelated cancers. In summary, this analysis of sequential specimens from patients with breast implant-associated ALCL suggests these neoplasms persist or progress over time if not treated with standard-of-care therapy.
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http://dx.doi.org/10.1038/s41379-021-00842-6DOI Listing
June 2021

Longitudinal single-cell profiling reveals molecular heterogeneity and tumor-immune evolution in refractory mantle cell lymphoma.

Nat Commun 2021 05 17;12(1):2877. Epub 2021 May 17.

Department of Lymphoma and Myeloma, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.

The mechanisms driving therapeutic resistance and poor outcomes of mantle cell lymphoma (MCL) are incompletely understood. We characterize the cellular and molecular heterogeneity within and across patients and delineate the dynamic evolution of tumor and immune cell compartments at single cell resolution in longitudinal specimens from ibrutinib-sensitive patients and non-responders. Temporal activation of multiple cancer hallmark pathways and acquisition of 17q are observed in a refractory MCL. Multi-platform validation is performed at genomic and cellular levels in PDX models and larger patient cohorts. We demonstrate that due to 17q gain, BIRC5/survivin expression is upregulated in resistant MCL tumor cells and targeting BIRC5 results in marked tumor inhibition in preclinical models. In addition, we discover notable differences in the tumor microenvironment including progressive dampening of CD8+ T cells and aberrant cell-to-cell communication networks in refractory MCLs. This study reveals diverse and dynamic tumor and immune programs underlying therapy resistance in MCL.
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http://dx.doi.org/10.1038/s41467-021-22872-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8128874PMC
May 2021

Clinical, immunophenotypic and genomic findings of NK lymphoblastic leukemia: a study from the Bone Marrow Pathology Group.

Mod Pathol 2021 07 1;34(7):1358-1366. Epub 2021 Feb 1.

Department of Pathology, Massachusetts General Hospital, Boston, MA, USA.

Natural killer (NK) cells are lymphocytes of the native immune system that play a pivotal role in host defense and immune surveillance. While the conceptual view of NK-neoplasms is evolving, little is known about the rare NK lymphoblastic leukemia (NK-LL), which remains as a provisional entity in the 2016 WHO Classification. The goal of this study is to characterize NK-LL cases and compare with other CD56 co-expressing acute leukemias. We identified 105 cases, diagnosed as NK-LL (6), CD56+ acute undifferentiated leukemia (AUL) (6), CD56+ T-lymphoblastic leukemia (T-LL) (51), and CD56+ acute myeloid leukemia (AML) (42). Compared to AUL patients, NK-LL patients were significantly younger (p = 0.021) and presented with higher white blood cell (WBC) (p = 0.037) and platelet counts (p = 0.041). Flow cytometry showed more frequent expression of cytoplasmic CD3 (cCD3, p = 0.064) and CD33, (p = 0.065), while HLA-DR was significantly absent from NK-LL (p = 0.035) compared to AUL. Compared to T-ALL, NK-LL cases showed less frequent cCD3 (p = 0.002), CD4 (p = 0.051), and CD10 expression (p = 0.06). The frequency of abnormal karyotypes was similar between NK-LL, AUL, and T-ALL. The mutational profile differed in four leukemia groups, with a significance enrichment of NOTCH1 (p = 0.002), ETV6 (p = 0.002) and JAK3 (p = 0.02) mutations in NK-LL as compared to AML. As compared to T-ALL, NK-LL cases showed a higher number of total mutations (p = 0.04) and significantly more frequent ETV6 mutations (p = 0.004). Clinical outcome data showed differences in overall survival between all four groups (p = 0.0175), but no difference in event free survival (p = 0.246). In this largest study to date, we find that that NK-LL shows clinical presentation, immunophenotypic and molecular characteristics distinct from AUL, T-ALL, and AML. Our findings suggest NK-LL is a distinct acute leukemia entity and should be considered in the clinical diagnosis of acute leukemias of ambiguous lineage.
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http://dx.doi.org/10.1038/s41379-021-00739-4DOI Listing
July 2021

The impact of cell-of-origin, MYC/Bcl-2 dual expression and rearrangement on disease relapse among early stage diffuse large B-cell lymphoma patients treated with combined modality therapy.

Leuk Lymphoma 2021 06 22;62(6):1361-1369. Epub 2021 Jan 22.

Departments of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.

We addressed the prognostic impact of cell-of-origin (COO), MYC and Bcl-2 overexpression as well as isolated rearrangement among 111 patients with limited stage diffuse large B-cell lymphoma (DLBCL) treated with consolidative radiation therapy (RT) after a metabolic complete response to immunochemotherapy. With a median follow-up of 31.1 months (95% CI 27.4 - 34.8), 4 relapses occurred. The 3-year progression free survival (PFS), overall survival (OS), and loco-regional relapse free survival (LRFS) for the cohort were 95%, 96%, and 100%, respectively. There were no differences in OS, PFS, or LRFS based on COO or MYC/Bcl-2 dual expression (DE). Similarly, patients with translocations without or rearrangements did not have worse outcomes. Consolidative RT produced excellent local control, regardless of DLBCL biology, with one late in-field failure.
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http://dx.doi.org/10.1080/10428194.2020.1869965DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8262455PMC
June 2021

Chronic myeloid neoplasms harboring concomitant mutations in myeloproliferative neoplasm driver genes (JAK2/MPL/CALR) and SF3B1.

Mod Pathol 2021 01 21;34(1):20-31. Epub 2020 Jul 21.

Department of Hematopathology, University of Texas MD Anderson Cancer Center, Houston, TX, USA.

JAK2, CALR, and MPL are myeloproliferative neoplasm (MPN)-driver mutations, whereas SF3B1 is strongly associated with ring sideroblasts (RS) in myelodysplastic syndrome (MDS). Concomitant mutations of SF3B1 and MPN-driver mutations out of the context of MDS/MPN with RS and thrombocytosis (MDS/MPN-RS-T) are not well-studied. From the cases (<5% blasts) tested by NGS panels interrogating at least 42 myeloid neoplasm-related genes, we identified 18 MDS/MPN-RS-T, 42 MPN, 10 MDS, and 6 MDS/MPN-U cases with an SF3B1 and an MPN-driver mutation. Using a 10% VAF difference to define "SF3B1-dominant," "MPN-mutation dominant," and "no dominance," the majority of MDS/MPN-RS-T clustered in "SF3B1-dominant" and "no dominance" regions. Aside from parameters as thrombocytosis and ≥15% RS required for RS-T, MDS also differed in frequent neutropenia, multilineage dysplasia, and notably more cases with <10% VAF of MPN-driver mutations (60%, p = 0.0346); MPN differed in more frequent splenomegaly, myelofibrosis, and higher VAF of "MPN-driver mutations." "Gray zone" cases with features overlapping MDS/MPN-RS-T were observed in over one-thirds of non-RS-T cases. This study shows that concomitant SF3B1 and MPN-driver mutations can be observed in MDS, MPN, and MDS/MPN-U, each showing overlapping but also distinctively different clinicopathological features. Clonal hierarchy, cytogenetic abnormalities, and additional somatic mutations may in part contribute to different disease phenotypes, which may help in the classification of "gray zone" cases.
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http://dx.doi.org/10.1038/s41379-020-0624-yDOI Listing
January 2021

Efficacy of venetoclax in high risk relapsed mantle cell lymphoma (MCL) - outcomes and mutation profile from venetoclax resistant MCL patients.

Am J Hematol 2020 06 17;95(6):623-629. Epub 2020 Apr 17.

Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.

Venetoclax is effective in relapsed patients with mantle cell lymphoma (MCL). Mechanisms of resistance to venetoclax in MCL are poorly understood. We describe the clinical outcomes and genomic characteristics of 24 multiply relapsed patients (median of five prior lines of therapy) who received venetoclax-based therapies; 67% had progressed on BTK inhibitors (BTKi) and 54% had blastoid or pleomorphic histology. Median follow up after venetoclax treatment was 17 months. The overall response rate was 50% and complete response (CR) rate was 21%, 16 patients had progressed and 15 died. The median progression free, overall and post venetoclax survival were 8, 13.5 and 7.3 months respectively. Whole-exome sequencing (WES) was performed on samples collected from seven patients (including five pairs; before starting venetoclax and after progression on venetoclax). The SMARCA4 and BCL2 alterations were noted only after progression, while TP53, CDKN2A, KMT2D, CELSR3, CCND1, NOTCH2 and ATM were altered 2-4-fold more frequently after progression. In two patients with serial samples, we demonstrated clonal evolution of novel SMARCA4 and KMT2C/D mutations at progression. Mutation dynamics in venetoclax resistant MCL is demonstrated. Our data indicates that venetoclax resistance in MCL is predominantly associated with non-BCL2 gene mutations. Further studies are ongoing in MCL patients to evaluate the efficacy of venetoclax in combination with other agents and understand the biology of venetoclax resistance in MCL.
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http://dx.doi.org/10.1002/ajh.25796DOI Listing
June 2020

Genomic profiles and clinical outcomes of de novo blastoid/pleomorphic MCL are distinct from those of transformed MCL.

Blood Adv 2020 03;4(6):1038-1050

Department of Imaging Physics, and.

Blastoid and pleomorphic mantle cell lymphomas (MCLs) are variants of aggressive histology MCL (AH-MCL). AH-MCL can arise de novo (AH-DN) or transform from prior classic variant MCL (AH-t). This study is the first integrated analysis of clinical and genomic characteristics of AH-MCL. Patient characteristics were collected from diagnosis (AH-DN) and at transformation (AH-t). Survival after initial diagnosis (AH-DN) and after transformation (AH-t) was calculated. Regression tree analysis was performed to evaluate prognostic variables and in univariate and multivariate analyses for survival. Whole-exome sequencing was performed in evaluable biopsy specimens. We identified 183 patients with AH-MCL (108 were AH-DN, and 75 were AH-t; 152 were blastoid, and 31 were pleomorphic). Median survival was 33 months (48 and 14 months for AH-DN and AH-t, respectively; P = .001). Factors associated with inferior survival were age (≥72 years), AH-t category, Ki-67 ≥50% and poor performance status. AH-t had a significantly higher degree of aneuploidy compared with AH-DN. Transformed MCL patients exhibited KMT2B mutations. AH-MCL patients with Ki-67 ≥50% had exclusive mutations in CCND1, NOTCH1, TP53, SPEN, SMARCA4, RANBP2, KMT2C, NOTCH2, NOTCH3, and NSD2 compared with low Ki-67 (<50%). AH-t patients have poor outcomes and distinct genomic profile. This is the first study to report that AH-MCL patients with high Ki-67 (≥50%) exhibit a distinct mutation profile and very poor survival.
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http://dx.doi.org/10.1182/bloodadvances.2019001396DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7094021PMC
March 2020

RAS and TP53 can predict survival in adults with T-cell lymphoblastic leukemia treated with hyper-CVAD.

Cancer Med 2020 02 5;9(3):849-858. Epub 2019 Dec 5.

Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.

Adult T-cell acute lymphoblastic leukemia (T-ALL) is a heterogeneous group of acute leukemias that account for about one third of all cases of Philadelphia chromosome (Ph)-negative ALL. Recently, a molecular classifier using the mutational status of NOTCH1, FBXW7, RAS, and PTEN (NFRP) has been shown to distinguish low- vs high-risk groups in adult T-ALL patients treated using the Berlin-Frankfurt-Münster ALL protocol. However, it is unknown if this molecular classifier can stratify adult T-ALL patients treated with hyper-CVAD ± nelarabine. We identified a relatively small cohort of 27 adults with T-ALL who were uniformly treated with hyper-CVAD ± nelarabine with available mutational analysis at time of diagnosis. The most commonly mutated genes in this group were NOTCH1 (52%), NRAS (22%), DNMT3A (19%), KRAS (15%), and TP53 (7%). The NFRP molecular classifier failed to stratify overall survival (OS; P = .84) and relapse-free survival (RFS; P = .18) in this cohort. We developed a new stratification model combining K/NRAS and TP53 mutations as high-risk factors and showed that mutations in these genes predicted poorer OS (P = .03) and RFS (P = .04). While the current study is limited by cohort size, these data suggest that the NFRP molecular classifier might not be applicable to adult T-ALL patients treated with hyper-CVAD ± nelarabine. RAS/TP53 mutation status, however, was useful in risk stratification in adults with T-ALL.
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http://dx.doi.org/10.1002/cam4.2757DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6997098PMC
February 2020

High-grade B-cell lymphoma: a term re-purposed in the revised WHO classification.

Pathology 2020 Jan 15;52(1):68-77. Epub 2019 Nov 15.

Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.

The designation high-grade B-cell lymphoma traditionally has been used as a general term for B-cell lymphomas that are morphologically aggressive with many mitotic figures, often a starry-sky pattern, and a high proliferation rate as shown by Ki-67 expression. These morphological features correlate with aggressive clinical behaviour. In the 2017 revision of the World Health Organization (WHO) classification of lymphomas, the term high-grade B-cell lymphoma has been re-purposed. Most cases in this category include so-called double and triple-hit lymphomas in the subgroup designated high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements. A smaller subset of cases are designated as high-grade B-cell lymphoma, not otherwise specified (NOS). This group is stated to be heterogeneous and includes neoplasms without double/triple-hit genetics as well as neoplasms that do not readily fit within the categories of diffuse large B-cell lymphoma NOS or Burkitt lymphoma. In most cases, accurate diagnosis can be achieved by integration of morphological, immunophenotypic and conventional cytogenetic and/or fluorescence in situ hybridisation (FISH) results. However, a few cases of high-grade B-cell lymphoma show overlapping features with different entities and can cause diagnostic difficulties. The WHO scheme is generally based on a 'snapshot' of current knowledge and, in our opinion, does not entirely capture the current state of knowledge of high-grade B-cell lymphomas. In this article, we review the topic of high-grade B-cell lymphoma as is currently described in the WHO classification, address recent developments, discuss difficulties one can encounter when applying the WHO scheme in daily practice, and we present some suggestions for the diagnostic workup of high-grade B-cell lymphomas.
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http://dx.doi.org/10.1016/j.pathol.2019.09.008DOI Listing
January 2020

Comparison of therapy-related myelodysplastic syndrome with ring sideroblasts and de novo myelodysplastic syndrome with ring sideroblasts.

Leuk Res 2019 11 17;86:106227. Epub 2019 Sep 17.

Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA. Electronic address:

Presence of RS is closely associated with SF3B1 mutation in de novo MDS. RS is also present in a subset of therapy-related MDS (t-MDS), but data is not available in t-MDS with RS (t-MDS-RS). Using NGS gene panel, we assessed t-MDS-RS (n = 38) and compared the result with d-MDS-RS (n = 174). Commonly mutated genes were TP53 (56.5%), TET2 (39.1%), SF3B1 (35.7%), ASXL1 (30.4%), DNMT3A (17.4%), RUNX1 (17.4%) and SRSF2 (14.3%). Compared with d-MDS-RS, TP53 mutation was more common but SF3B1 mutation was less common in t-MDS-RS (p < 0.05). In t-MDS-RS, Mutations in 4 genes (SF3B1, U2AF1, SRSF2 and ZRSR2) involving the RNA splicing were found in about 50% of patients compared to ˜90% in d-MDS-RS. Overall survival was by far worse in t-MDS-RS compared to d-MDS-RS (median overall survival: 10.9 months and 111.9 months in t-MDS-RS and d-MDS-RS, respectively, p < 0.05). Progression to acute myeloid leukemia was more common in t-MDS-RS (18.4% vs. 7.4% in t-MDS-RS and d-MDS-RS, respectively, p < 0.05). Unlike de novo MDS, t-MDS-RS did not have different outcome compared to t-MDS without RS (median OS: 10.9 months vs. 14.3 months, respectively, p = 0.2341). Our data demonstrate that presence of RS is not associated with superior outcome in t-MDS. Mutation profiles suggest RS in t-MDS might be a secondary event in at least 50% of the cases or not related to mutations in RNA splicing machinery unlike d-MDS where mutations in RNA splicing machinery occur early and as associated with ineffective erythropoiesis.
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http://dx.doi.org/10.1016/j.leukres.2019.106227DOI Listing
November 2019

Homogeneously staining region (hsr) on chromosome 11 is highly specific for KMT2A amplification in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS).

Cancer Genet 2019 10 5;238:18-22. Epub 2019 Jul 5.

Department of Hematopathology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030-4009, United States.

AML and MDS are most common myeloid neoplasms that affect mainly older patients. Overexpression of certain proto-oncogenes plays an indispensable role in tumorigenesis and overexpression can be a consequence of gene rearrangement, amplification and/or mutation. Rearrangement and amplification of KMT2A located at chromosome band 11q23 is a well-characterized genetic driver in a subset of AML/MDS cases and is associated with a poor prognosis. The presence of homogeneously staining regions (hsr) also has been correlated with amplification of specific proto-oncogenes. In this study, we correlated hsr(11)(q23) with KMT2A in a large cohort of AML/MDS (n = 54) patients. We identified 37 patients with hsr(11)(q23) in the setting of AML (n = 27) and MDS (n = 10). All patients showed a complex karyotype including 12 cases with monosomy 17. KMT2A FISH analysis was available for 35 patients which showed KMT2A amplification in all patients. Among control cases with hsr involving chromosomes other than 11q [non-11q hsr, n = 17], FISH analysis for KMT2A was available in 10 cases and none of these cases showed KMT2A amplification (p = 0.0001, Fisher's exact test, two-tailed). Mutational analysis was performed in 32 patients with hsr(11)(q23). The most common mutated gene was TP53 (n = 29), followed by DNMT3A (n = 4), NF1 (n = 4), and TET2 (n = 3). Thirty (83%) patients died over a median follow-up of 7.6 months (range, 0.4-33.4). In summary, hsr(11)(q23) in AML/MDS cases is associated with a complex karyotype, monosomy 17, KMT2A amplification, and TP53 mutation.
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http://dx.doi.org/10.1016/j.cancergen.2019.07.001DOI Listing
October 2019

Somatic molecular analysis augments cytologic evaluation of pancreatic cyst fluids as a diagnostic tool.

Oncotarget 2019 Jun 18;10(40):4026-4037. Epub 2019 Jun 18.

University of Massachusetts Medical School, Department of Pathology, Worcester, MA, USA.

Better tools are needed for early diagnosis and classification of pancreatic cystic lesions (PCL) to trigger intervention before neoplastic precursor lesions progress to adenocarcinoma. We evaluated the capacity of molecular analysis to improve the accuracy of cytologic diagnosis for PCL with an emphasis on non-diagnostic/negative specimens. In a span of 7 years, at a tertiary care hospital, 318 PCL endoscopic ultrasound-guided fine needle aspirations (EUS-FNA) were evaluated by cytologic examination and molecular analysis. Mucinous PCL were identified based on a clinical algorithm and 46 surgical resections were used to verify this approach. The mutation allele frequency (MAF) of commonly altered genes (, , , , , , , , and ) was evaluated for their ability to identify and grade mucinous PCL. Cytology showed a diagnostic sensitivity of 43.5% for mucinous PCL due in part to the impact of non-diagnostic (28.8%) and negative (50.5%) specimens. Incorporating an algorithmic approach or molecular analysis markedly increased the accuracy of cytologic evaluation. Detection of mucinous PCL by molecular analysis was 93.3% based on the detection of and/or gene mutations ( = 0.0001). Additional genes provided a marginal improvement in sensitivity but were associated with cyst type (e.g. ) and grade (e.g. ). In the surgical cohort, molecular analysis and the proposed algorithm showed comparable sensitivity (88.9% vs. 100%). Incorporating somatic molecular analysis in the cytologic evaluation of EUS-FNA increases diagnostic accuracy for detection, classification and grading of PCL. This approach has the potential to improve patient management.
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http://dx.doi.org/10.18632/oncotarget.26999DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6592293PMC
June 2019

Mantle Cell Lymphoma Involving Skin: A Clinicopathologic Study of 37 Cases.

Am J Surg Pathol 2019 10;43(10):1421-1428

Departments of Hematopathology.

Mantle cell lymphoma (MCL) rarely involves the skin and the histologic and immunohistochemical features of this neoplasm at this site are under described. In this study, we report 37 skin specimens involved by MCL, representing 1.4% of total MCL biopsy specimens in our institution. The median age at time of skin involvement was 66 years (range, 36 to 85 y) and there was a male predilection of 2.7 to 1. The most frequently involved site was the skin of extremities, in 59.3% of patients, and 30 (81.1%) patients had advanced stage (III/IV) disease. Eleven (29.7%) patients presented with skin lesions as the first manifestation of MCL and 26 (70.3%) patients presented as relapse or progression of previously documented MCL and despite therapy for systemic MCL. Multiple skin lesions were more common (81.8%) in the former group whereas a solitary skin lesion was more frequent (65.4%) in the relapse/progression group (P=0.01). Thirty (81.1%) patients had skin nodules. Microscopically, the epidermis was spared with a grenz zone in all cases. A diffuse pattern of involvement was the most common architectural pattern (66.7%). In 27 (72.9%) patients, the MCL was either blastoid or pleomorphic variant, in 9 (24.3%) patients classic variant, and the disease was not further classified in 1 (2.7%) patient. The Ki-67 proliferation rate was higher in aggressive variants as compared with classic variant MCL (median 90% vs. 20%, P <0.01). In patients who presented skin lesions as a manifestation of disease relapse or progression, 16 patients initially had classic variant MCL and in 10 of the patients the MCL evolved over time (median interval: 4.1 y) to an aggressive variant at progression or relapse. The overall survival of patients with aggressive variant MCH was inferior to that of patients with classic variant MCL (median: 59 vs. 155.8 mo, P<0.05). In summary, MCL rarely involves the skin and correlates with relapse or progression of disease, aggressive morphologic features, and a poorer prognosis.
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http://dx.doi.org/10.1097/PAS.0000000000001312DOI Listing
October 2019

Low-Grade Myelodysplastic Syndromes with Preserved CD34+ B-Cell Precursors (CD34+ Hematogones).

Cytometry B Clin Cytom 2020 01 18;98(1):36-42. Epub 2019 Jun 18.

Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas.

B-cell progenitors (hematogones) are markedly decreased or completely absent in the bone marrows of myelodysplastic syndromes (MDS), and the finding is considered as an important feature in MDS flow cytometry immunophenotyping. We studied CD34+ hematogones as a proportion of total CD34+ cells in 160 treatment naïve low grade primary MDS patients, consecutively collected over a two-year period. While confirming that the median CD34 + hematogones was significantly decreased (1.08%, 0%, to 67.86%), we observed variably preserved CD34 + hematogones in some MDS patients. Using a 5% cutoff, a total of 46 (29%) MDS patients had ≥5% CD34 + hematogones, significantly overrepresented by MDS with ring sideroblasts (RS) (MDS-RS) (18/40, 45%, vs. 28/120, 23%, P = 0.015). While we did not observe unique features among MDS-RS, mutations were noticeably absent in a significant number of MDS without RS (37% vs. 14%, P = 0.013), including TP53 mutations (0% vs.16.5%, P = 0.021) if ≥5% CD34 + hematogones were present. Although the follow up was short (18.5 months, 0 to 151.0), a better overall survival was observed in MDS with ≥5% CD34 + hematogones, either as a group (P = 0.008) or among patients with no RS (P = 0.028). In multivariate analysis, reduced hematogones remained to be significant hazard (P = 0.015). In summary, preserved CD34 + hematogones (≥5%) are seen in over a quarter of primary low-grade MDS and these cases are overrepresented by MDS with RS or MDS with no detectable mutations. The finding is new, and this phenomenon may in part attribute to preservation of B-cell differentiation of CD34+ progenitors, and it is associated with a better prognosis in low grade MDS patients. © 2019 International Clinical Cytometry Society.
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http://dx.doi.org/10.1002/cyto.b.21830DOI Listing
January 2020

TP53 mutations are common in mantle cell lymphoma, including the indolent leukemic non-nodal variant.

Ann Diagn Pathol 2019 Aug 16;41:38-42. Epub 2019 May 16.

Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America. Electronic address:

Introduction: Mantle cell lymphoma (MCL) is an aggressive B-cell neoplasm, but clinically indolent subtypes are also recognized. Data on the utility of mutation profiling in the context of routine workup and its role in risk-stratification of MCL patients are limited. In this study, we describe the mutational landscape and clinicopathologic correlates of a series of MCL cases at a single-institution setting.

Methods: Samples from 26 patients with MCL were evaluated by NGS using DNA extracted from peripheral blood (PB) or bone marrow (BM). Evaluation of extent of PB or BM involvement was performed using flow cytometry immunophenotyping.

Results: The study group included 17 (65%) men and 9 (35%) women with a median age of 65 years (range, 50-94). Twenty-one (81%) patients had nodal MCL (N-MCL) and 5 (19%) had the "leukemic variant" (L-MCL). Mutated genesincluded TP53 (35%), ATM (27%), CARD11 (10%); and FBXW7, NOTCH1, SPEN, BIRC3 (~5% each). Most mutations were clonal in nature. Ten unique TP53 mutations were identified in 9 samples, including 3 L-MCL cases. There was no difference in the frequency of TP53 mutations between L-MCL and N-MCL groups (p = 0.3), but TP53 mutations were subclonal in 2/3 L-MCL cases. Identification of clonal TP53 alterations in L-MCL patients prompted initiation of therapy despite low tumor burden.

Conclusions: TP53 is commonly mutated in MCL. TP53 mutations may be clonal or subclonal. Seemingly indolent L-MCL may harbor subclonal TP53 mutations which may serve as a useful biomarker for prognostication, therapeutic planning, follow-up monitoring, and early detection of clonal expansion.
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http://dx.doi.org/10.1016/j.anndiagpath.2019.05.004DOI Listing
August 2019

Clinical, immunophenotypic, and genomic findings of acute undifferentiated leukemia and comparison to acute myeloid leukemia with minimal differentiation: a study from the bone marrow pathology group.

Mod Pathol 2019 09 18;32(9):1373-1385. Epub 2019 Apr 18.

Department of Pathology and Laboratory Medicine, University of Chicago, Chicago, IL, USA.

Acute undifferentiated leukemia is a rare type of acute leukemia that shows no evidence of differentiation along any lineage. Clinical, immunophenotypic and genetic data is limited and it is uncertain if acute undifferentiated leukemia is biologically distinct from acute myeloid leukemia with minimal differentiation, which also shows limited myeloid marker expression and has been reported to have a poor prognosis. We identified 92 cases initially diagnosed as acute undifferentiated leukemia or acute myeloid leukemia with minimal differentiation from pathology databases of nine academic institutions with available diagnostic flow cytometric data, cytogenetic findings, mutational and clinical data. Outcome analysis was performed using Kaplan Meier test for the 53 patients who received induction chemotherapy. Based on cytogenetic abnormalities (N = 30) or history of myelodysplastic syndrome (N = 2), 32 cases were re-classified as acute myeloid leukemia with myelodysplasia related changes. The remaining 24 acute undifferentiated leukemia patients presented with similar age, blood counts, bone marrow cellularity, and blast percentage as the remaining 30 acute myeloid leukemia with minimal differentiation patients. Compared to acute myeloid leukemia with minimal differentiation, acute undifferentiated leukemia cases were characterized by more frequent mutations in PHF6 (5/15 vs 0/19, p = 0.016) and more frequent expression of TdT on blasts (p = 0.003) while acute myeloid leukemia with minimal differentiation cases had more frequent CD123 expression (p = 0.042). Outcome data showed no difference in overall survival, relapse free survival, or rates of complete remission between acute undifferentiated leukemia and acute myeloid leukemia with minimal differentiation groups (p > 0.05). Acute myeloid leukemia with myelodysplasia-related changes patients showed shorter survival when censoring for bone marrow transplant as compared to acute undifferentiated leukemia (p = 0.03) and acute myeloid leukemia with minimal differentiation (p = 0.002). In this largest series to date, the acute undifferentiated leukemia group shows distinct characteristics from acute myeloid leukemia with minimal differentiation, including more frequent PHF6 mutations and expression of TdT.
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http://dx.doi.org/10.1038/s41379-019-0263-3DOI Listing
September 2019

American Registry of Pathology Expert Opinions: Immunohistochemical evaluation of classic Hodgkin lymphoma.

Ann Diagn Pathol 2019 Apr 6;39:105-110. Epub 2019 Feb 6.

Mayo Clinic, Rochester, MN, United States of America.

The diagnosis of classic Hodgkin lymphoma requires immunohistochemical confirmation in most cases and one can argue for these studies as standard-of-care in the diagnostic workup. The authors propose a panel of studies for primary identification of CHL to include: CD3, CD20, CD15, CD30 and PAX5. When pattern discordances are identified, additional assessment is recommended. In the case of overexpression of B lineage markers by Hodgkin/Reed-Sternberg cells, or a differential diagnosis that includes large B-cell lymphoma or variants, additional markers recommended are: CD45, OCT2, BOB1, CD79a and MUM1/IRF4. If primary mediastinal large B cell lymphoma is considered in the differential diagnosis, suggested additional markers include: P63, CD23, CD45 and CD79a. When considering a differential diagnosis that includes anaplastic large cell lymphoma we suggest: ALK, CD45, pan T cell antigens (such as CD2, CD5, CD7, and CD43), and cytotoxic markers (granzyme, perforin, and TIA1). If peripheral T cell lymphoma or T cell lymphomas of follicular helper origin are considered in the differential diagnosis, the following panel is recommended: pan T cell antigens, CD4, CD8, one or more follicular dendritic cell markers, and assessment for Epstein-Barr virus (EBV) infection, preferably EBV encoded RNA (EBER) as assessed by in situ hybridization When the differential diagnosis includes nodular lymphocyte predominant Hodgkin lymphoma, recommended additional studies include OCT2, CD21 and/or CD23, PD1, and assessment for EBV infection. The authors recognize that these panels may not be adequate to completely characterize other lymphomas, but these panels will usually be sufficient to distinguish classic Hodgkin lymphoma from other lymphoma types.
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http://dx.doi.org/10.1016/j.anndiagpath.2019.02.001DOI Listing
April 2019

Ultra-Rapid Reporting of GENomic Targets (URGENTseq): Clinical Next-Generation Sequencing Results within 48 Hours of Sample Collection.

J Mol Diagn 2019 01;21(1):89-98

Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas.

Next-generation sequencing (NGS)-based mutation panels profile multiple genes simultaneously, allowing the reporting of numerous genes while saving labor and resources. However, one drawback of using NGS is that the turnaround time is often longer than conventional single gene tests. This delay can be problematic if molecular results are required to guide therapy in patients with clinically aggressive diseases, such as acute myeloid leukemia. To overcome this limitation, we developed a novel custom platform designated as Ultra-rapid Reporting of GENomic Targets (URGENTseq), an integrated solution that includes workflow optimization and an innovative custom bioinformatics pipeline to provide targeted NGS results on fresh peripheral blood and bone marrow samples within an actionable time period. URGENTseq was validated for clinical use by determining mutant allelic frequency and minimum coverage in silico to achieve 100% concordance for all positive and negative calls between the URGENTseq and conventional sequencing approach. URGENTseq enables the reporting of selected genes useful for immediate diagnosis (CALR, CSF3R, JAK2, KRAS, MPL, NPM1, NRAS, SF3B1) and treatment decisions (IDH1, IDH2) in hematologic malignancies within 48 hours of specimen collection. In addition, we summarize the molecular findings of the first 272 clinical test results performed using the URGENTseq platform.
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http://dx.doi.org/10.1016/j.jmoldx.2018.08.002DOI Listing
January 2019

High-grade B-cell lymphomas with TdT expression: a diagnostic and classification dilemma.

Mod Pathol 2019 01 4;32(1):48-58. Epub 2018 Sep 4.

Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.

Mature B-cell neoplasms and immature or precursor B-cell neoplasms need to be distinguished because these patients usually require different therapeutic approaches. B-cell neoplasms that express TdT without unequivocal other features of immaturity may therefore present a diagnostic challenge. We describe 13 patients with TdT-positive aggressive B-cell lymphoma. The clinicopathologic features of these patients were highly heterogeneous, but for the purpose of this study we grouped these cases as follows: (1) de novo high-grade B-cell lymphoma with MYC, BCL2, and/or BCL6 rearrangements (double-hit or triple-hit lymphoma) with TdT expression. In this group we included two cases of de novo composite lymphoma in which there were components of diffuse large B-cell lymphoma and TdT-positive blastic B-cell lymphoma; (2) TdT-positive aggressive B-cell lymphoma arising in patients who previously had follicular lymphoma; (3) initial relapse of TdT-negative aggressive B-cell lymphoma in patients who previously had follicular lymphoma, followed by relapses in which the neoplasm acquired TdT expression; and (4) mature B-cell lymphomas that acquired TdT expression at relapse. This group included one case of EBV-positive diffuse large B-cell lymphoma and one case of pleomorphic variant mantle cell lymphoma. All patients in this study had an aggressive clinical course and a dismal outcome despite appropriate therapy. Rather than "squeezing" these cases into current World Health Organization classification categories, we suggest the use of a descriptive term such as high-grade B-cell lymphoma with TdT expression. In these tumors, the cytogenetic findings and poor prognosis of this patient subgroup suggest that these neoplasms need to be distinguished from B-lymphoblastic leukemia/lymphoma. Segregation of these neoplasms also may foster additional research on these neoplasms.
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http://dx.doi.org/10.1038/s41379-018-0112-9DOI Listing
January 2019

Long-term outcomes and mutation profiling of patients with mantle cell lymphoma (MCL) who discontinued ibrutinib.

Br J Haematol 2018 11 2;183(4):578-587. Epub 2018 Sep 2.

Department of Lymphoma and Myeloma, the University of Texas MD Anderson Cancer Center, Houston, TX, USA.

Long term outcomes and mutations in patients with mantle cell lymphoma (MCL) who discontinued ibrutinib have not been described. Using deep targeted next generation sequencing, we performed somatic mutation profiling from 15 MCL patients (including 5 patients with paired samples; before and after progression on ibrutinib). We identified 80 patients with MCL who discontinued ibrutinib therapy for various reasons. Median follow-up after ibrutinib discontinuation was 38 months. The median duration on ibrutinib was 7·6 months. Forty-one (51%) patients discontinued ibrutinib due to disease progression/transformation, 20 (25%) for intolerance, 7 (9%) due to patient choice, 5 (6%) for stem cell transplant, 4 (5%) due to second cancers and 3 (4%) other causes. The median survival after ibrutinib was 10 and 6 months for disease progression and transformation, respectively, and 25 months for patients with ibrutinib intolerance. Overall, BTK mutations were observed in 17% patients after progression on ibrutinib. Notably, TP53 alterations were observed after progression in 75% patients. Among the 4 patients with blastoid transformation, 3 (75%) had NSD2 mutations (co-existing with TP53). Ibrutinib-refractory MCL patients had a short survival. Demonstration of TP53 and NSD2 mutations in patients who developed blastoid transformation and ATM and TP53 mutations in patients who progressed, opens the door for future investigations in ibrutinib-refractory MCL.
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http://dx.doi.org/10.1111/bjh.15567DOI Listing
November 2018

Persistent mutations in remission can predict relapse in patients with acute myeloid leukemia.

Haematologica 2019 02 31;104(2):305-311. Epub 2018 Aug 31.

Department of Hematopathology

Persistence of or mutations in remission bone marrow specimens of patients with acute myeloid leukemia has been observed, but the clinical impact of these mutations is not well known. In this study, we evaluated 80 acute myeloid leukemia patients with known R132 or R140/R172 mutations and assessed their bone marrow at the time of remission to determine the potential impact of persistent mutations. Approximately 40% of acute myeloid leukemia patients given standard treatment in this cohort had persistent mutations in Patients with an mutation had an increased risk of relapse after 1 year of follow-up compared to patients without a detectable mutation (59% 24%; <0.01). However, a persistent mutation was not associated with a shorter time to relapse. High mutation burden (mutant allelic frequency ≥10%) did not correlate with relapse rate (77% 86% for patients with a low burden, i.e., mutant allelic frequency <10%; =0.66). Persistent mutations were also observed in , and during remission, but mutations remained significant in predicting relapse by multivariate analysis. Flow cytometry was comparable and complementary to next-generation sequencing-based assay for predicting relapse. Monitoring for persistent mutations in patients with acute myeloid leukemia in remission can provide information that could be used to justify early interventions, with the hope of facilitating longer remissions and better outcomes in these patients.
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http://dx.doi.org/10.3324/haematol.2018.191148DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6355476PMC
February 2019

Genomic and clinical characterization of B/T mixed phenotype acute leukemia reveals recurrent features and T-ALL like mutations.

Am J Hematol 2018 11 26;93(11):1358-1367. Epub 2018 Sep 26.

Department of Pathology, Boston Children's Hospital, Boston, Massachusetts.

The B/T subtype of mixed phenotype acute leukemia (B/T MPAL) is defined by co-expression of antigens of both B- and T-cell lineages on leukemic blasts. Although it has been suggested that multilineage antigen expression portends poor response to chemotherapy, the clinical characteristics and driver mutations that underlie the pathogenesis of this rare subtype of acute leukemia are scarcely known. We identified nine cases of B/T MPAL from multiple institutions and correlated clinical and immunophenotypic findings with next-generation sequencing data. We report that B/T MPAL commonly presents with lymphadenopathy in adolescence and young adulthood. While the tumors have diverse cytogenetic and genomic perturbations, recurrent acquired aberrations include mutations in the putative transcriptional regulator PHF6 and the JAK-STAT and Ras signaling pathways. Alterations were also identified in genes encoding hematopoietic transcription factors, cell cycle regulators/tumor suppressors, and chromatin modifying enzymes. The genomic landscape of B/T MPAL strongly resembles that of T-ALL subgroups associated with early developmental arrest, while genetic alterations that are common in B-ALL were rarely seen. Two-thirds of the patients responded to ALL-based chemotherapy with or without stem cell transplantation. Our observations lay the groundwork for further study of the unique biology and clinical trajectory of B/T MPAL.
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http://dx.doi.org/10.1002/ajh.25256DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8193761PMC
November 2018

Chronic lymphocytic leukemia with proliferation centers in bone marrow is associated with younger age at initial presentation, complex karyotype, and TP53 disruption.

Hum Pathol 2018 12 4;82:215-231. Epub 2018 Aug 4.

Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. Electronic address:

The presence of expanded proliferation centers (PCs) in lymph nodes involved by chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma has been associated with adverse clinical outcomes, but the frequency and significance of PCs in bone marrow (BM) remain unclear. The study group included 36 patients with BM involvement by CLL in which PCs were present. We compared this group with 110 randomly selected BM samples involved by CLL without morphologically discernable PCs. Patients with PCs in BM were younger (median age, 53 years [range,18-71 years] versus 58 years [range, 31-82 years]; P = .007), more frequently experienced B symptoms (27.8% versus 8.2%, P = .0076), more often had Rai stage IV disease (30.6% versus 17.3%, P = .02) and higher serum lactate dehydrogenase (P = .0037) and β-microglobulin (P = .0001) levels, and lower hemoglobin (P = .026) and platelet counts (P = .0422). TP53 alterations were more common in patients with PCs in BM (45.4% versus 18.7%; P = .0049), as was a complex karyotype (26.4% versus 9%; P = .019). There were no significant differences in the frequency of ZAP70 or CD38 positivity or IGHV mutation status. The median time to first treatment was shorter in patients with PCs in BM (7 months versus 19 months, P = .047), and the frequency of Richter syndrome was higher (14% versus 4%, P = .041). Patients with PCs in BM had significantly shorter overall survival compared with the control group (median, 249.3 months versus undefined; P = .0241). These data suggest that identification of PCs in BM samples involved by CLL is associated with adverse prognostic features.
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http://dx.doi.org/10.1016/j.humpath.2018.07.030DOI Listing
December 2018

Mixed phenotype acute leukemia contains heterogeneous genetic mutations by next-generation sequencing.

Oncotarget 2018 Feb 3;9(9):8441-8449. Epub 2018 Jan 3.

Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.

Mixed phenotype acute leukemia (MPAL) is an uncommon manifestation of acute leukemia. The aim of this study is to further characterize the genetic landscape of cases of MPAL that fulfill the 2016 World Health Organization (WHO) classification criteria for this entity. We identified 14 cases examined by next generation sequencing (NGS) using 28 ( 10), 53 ( 3) or 81 ( 1) gene panels: 7 cases with a B-cell/myeloid (B/My) immunophenotype, 6 T-cell/myeloid (T/My) immunophenotype, and 1 B-cell/T-cell (B/T) immunophenotype. A total of 25 distinct mutations were identified in 15 different genes in 9/14 (64%) patients. -ITD was the only recurrent mutation in 2 patients. B/My MPAL cases less commonly harbored mutations compared with T/My MPAL cases (43% vs. 100%, = 0.07). In contrast, B/My MPALs more commonly showed a complex karyotype compared to T/My MPALs (71% vs. 17%, = 0.1). With NGS and karyotype combined, most (93%) MPAL cases had mutations or cytogenetic abnormalities. With a median follow-up of 12.5 months, there were no significant differences in median overall survival (OS) between patients with B/My or T/My MPAL (17.8 and 6.5 months, respectively, = 0.81) or between patients with MPAL with versus without gene mutations (6.5 and 13.3 months, respectively, = 0.86). Our data suggest that the distinguishing cases of MPAL according to immunophenotype has value because the underlying mechanisms of leukemogenesis might differ between B/My and T/My MPAL.
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http://dx.doi.org/10.18632/oncotarget.23878DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5823573PMC
February 2018

Myelodysplastic Syndrome, Unclassifiable (MDS-U) With 1% Blasts Is a Distinct Subgroup of MDS-U With a Poor Prognosis.

Am J Clin Pathol 2017 Jul;148(1):49-57

Department of Pathology and Laboratory Medicine, Weill Cornell Medical College/New York Presbyterian Hospital, New York, NY.

Objectives: Three situations qualify as myelodysplastic syndrome, unclassifiable (MDS-U): (1) refractory cytopenia with dysplasia and 1% blasts in peripheral blood (BL), (2) pancytopenia with unilineage dysplasia (Pan), and (3) persistent cytopenia, less than 5% bone marrow blasts, and less than 10% dysplastic cells and presence of MDS-defining cytogenetic abnormalities (CG). We compared the clinicopathologic features and mutational profiles for these three groups.

Methods: MDS-U cases were reviewed at four major academic institutions. Targeted next-generation sequencing for genes implicated in myeloid neoplasms was performed in a subset of cases.

Results: Twenty-seven patients were identified (six MDS-U BL, 13 MDS-U Pan, and eight MDS-U CG). Clonal cytogenetic abnormalities were found in six of six, seven of 13, and eight of eight cases in MDS-U BL, Pan, and CG, respectively (P > .05). Overall, four of six patients with MDS-U BL progressed to acute myeloid leukemia; no MDS-U Pan or CG patients did. The rates of progression-free survival and mortality (overall survival) were significantly higher in MDS-U BL compared with Pan and CG (P < .001 for both).

Conclusions: We find that MDS-U BL is a distinct subset of MDS-U with a poor prognosis, while MDS-U Pan and CG are relatively indolent. Evaluation of peripheral blood smears in patients with MDS is essential for accurate classification and prognosis.
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http://dx.doi.org/10.1093/ajcp/aqx043DOI Listing
July 2017

Characterization of TP53 mutations in low-grade myelodysplastic syndromes and myelodysplastic syndromes with a non-complex karyotype.

Eur J Haematol 2017 Dec 20;99(6):536-543. Epub 2017 Oct 20.

Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.

Objectives: Although commonly associated with high-grade myelodysplastic syndrome (MDS) and MDS with a complex karyotype, TP53 mutations also occur in low-grade MDS and MDS with a non-complex karyotype. In latter cases, their clinicopathological features and the characteristics of TP53 mutations remain poorly characterized.

Methods: 176 MDS cases with TP53 mutations were stratified and characterized based on their karyotype and histologic subtype.

Results: Among 176 cases, 17% had a non-complex karyotype and 24% were low-grade MDS. TP53 mutations often occurred in DNA-binding domains and the majority of cases had only one mutation, irrespective of their karyotype and MDS subtype. The variant allele frequency (VAF), however, was associated with karyotype complexity and the types of MDS with a lower VAF found in cases with a non-complex karyotype and low-grade MDS. A low (<20%) VAF was associated with a better survival, as well as low-grade subtype.

Conclusions: In low-grade MDS and MDS with a non-complex karyotype, TP53 mutations showed a lower VAF. Patients with a lower VAF had a better survival. TP53 mutations are not the only prognostic factor in MDS patients with TP53 mutations as the VAF, blast counts and history of prior therapy also play important roles in prognosis.
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http://dx.doi.org/10.1111/ejh.12971DOI Listing
December 2017
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