Publications by authors named "Jason Thorpe"

21 Publications

  • Page 1 of 1

The effect of referral for genetic counseling on genetic testing and surgical prevention in women at high risk for ovarian cancer: Results from a randomized controlled trial.

Cancer 2016 Nov 22;122(22):3509-3518. Epub 2016 Jul 22.

Translational Outcomes Research, Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington.

Background: Guidelines recommend genetic counseling and testing for women who have a pedigree suggestive of an inherited susceptibility for ovarian cancer. The authors evaluated the effect of referral to genetic counseling on genetic testing and prophylactic oophorectomy in a randomized controlled trial.

Methods: Data from an electronic mammography reporting system identified 12,919 women with a pedigree that included breast cancer, of whom 625 were identified who had a high risk for inherited susceptibility to ovarian cancer using a risk-assessment questionnaire. Of these, 458 women provided informed consent and were randomized 1:1 to intervention consisting of a genetic counseling referral (n = 228) or standard clinical care (n = 230).

Results: Participants were predominantly aged 45 to 65 years, and 30% and 20% reported a personal history of breast cancer or a family history of ovarian cancer, respectively. Eighty-five percent of women in the intervention group participated in a genetic counseling session. Genetic testing was reported by 74 (33%) and 20 (9%) women in the intervention and control arms (P < .005), respectively. Five women in the intervention arm and 2 in the control arm were identified as germline mutation carriers. Ten women in the intervention arm and 3 in the control arm underwent prophylactic bilateral salpingo-oophorectomy (P < .05).

Conclusions: Routine referral of women at high risk for ovarian cancer to genetic counseling promotes genetic testing and prophylactic surgery. The findings from the current randomized controlled trial demonstrate the value of implementing strategies that target women at high risk for ovarian cancer to ensure they are offered access to recommended care. CA Cancer J Clin 2016. © 2016 American Cancer Society, Inc. Cancer 2016;122:3509-3518. © 2016 American Cancer Society.
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November 2016

Evaluating Serum Markers for Hormone Receptor-Negative Breast Cancer.

PLoS One 2015 13;10(11):e0142911. Epub 2015 Nov 13.

Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Seattle, Washington, United States of America.

Introduction: Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death in females worldwide. Death rates have been declining, largely as a result of early detection through mammography and improved treatment, but mammographic screening is controversial because of over-diagnosis of breast disease that might not require treatment, and under-diagnosis of cancer in women with dense breasts. Breast cancer screening could be improved by pairing mammography with a tumor circulating marker, of which there are currently none. Given genomic similarities between the basal breast cancer subtype and serous ovarian cancer, and given our success in identifying circulating markers for ovarian cancer, we investigated the performance in hormone receptor-negative breast cancer detection of both previously identified ovarian serum markers and circulating markers associated with transcripts that were differentially expressed in breast cancer tissue compared to healthy breast tissue from reduction mammaplasties.

Methods: We evaluated a total of 15 analytes (13 proteins, 1 miRNA, 1 autoantibody) in sera drawn at or before breast cancer surgery from 43 breast cancer cases (28 triple-negative-TN-and 15 hormone receptor-negative-HRN-/ HER2-positive) and 87 matched controls.

Results: In the analysis of our whole cohort of breast cancer cases, autoantibodies to TP53 performed significantly better than the other selected 14 analytes showing 25.6% and 34.9% sensitivity at 95% and 90% specificity respectively with AUC: 0.7 (p<0.001). The subset of 28 TN cancers showed very similar results. We observed no correlation between anti-TP53 and the 14 other markers; however, anti-TP53 expression correlated with Body-Mass-Index. It did not correlate with tumor size, positive lymph nodes, tumor stage, the presence of metastases or recurrence.

Conclusion: None of the 13 serum proteins nor miRNA 135b identified women with HRN or TN breast cancer. TP53 autoantibodies identified women with HRN breast cancer and may have potential for early detection, confirming earlier reports. TP53 autoantibodies are long lasting in serum but may be affected by storage duration. Autoantibodies to TP53 might correlate with Body-Mass-Index.
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June 2016

Identifying post-menopausal women at elevated risk for epithelial ovarian cancer.

Gynecol Oncol 2015 Nov 3;139(2):253-60. Epub 2015 Sep 3.

Fred Hutchinson Cancer Research Center, Seattle, WA, United States.

Objective: We developed and validated a hybrid risk classifier combining serum markers and epidemiologic risk factors to identify post-menopausal women at elevated risk for invasive fallopian tube, primary peritoneal, and ovarian epithelial carcinoma.

Methods: To select epidemiologic risk factors for use in the classifier, Cox proportional hazards analyses were conducted using 74,786 Women's Health Initiative (WHI) Observational Study (OS) participants. To construct a combination classifier, 210 WHI OS cases and 536 matched controls with serum marker measurements were analyzed; validation employed 143 cases and 725 matched controls from the WHI Clinical Trial (CT) with similar data.

Results: Analyses identified a combination risk classifier composed of two elevated-risk groups: 1) women with CA125 or HE4 exceeding a 98% specificity threshold; and 2) women with intact fallopian tubes, prior use of menopausal hormone therapy for at least two years, and either a first degree relative with breast or ovarian cancer or a personal history of breast cancer. In the WHI OS population, it classified 13% of women as elevated risk, identifying 30% of ovarian cancers diagnosed up to 7.8years post-enrollment (Hazard Ratio [HR]=2.6, p<0.001). In the WHI CT validation population, it classified 8% of women as elevated risk, identifying 31% of cancers diagnosed within 7years of enrollment (HR=4.6, p<0.001).

Conclusion: CA125 and HE4 contributed significantly to a risk prediction classifier combining serum markers with epidemiologic risk factors. The hybrid risk classifier may be useful to identify post-menopausal women who would benefit from timely surgical intervention to prevent epithelial ovarian cancer.
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November 2015

Validation of LRG1 as a potential biomarker for detection of epithelial ovarian cancer by a blinded study.

PLoS One 2015 23;10(3):e0121112. Epub 2015 Mar 23.

University of Michigan, Department of Surgery, Ann Arbor, MI, United States of America.

Background: Leucine-rich alpha-2-glycoprotein (LRG1) was found to be differentially expressed in sera from patients with Epithelial Ovarian Cancer (EOC). The aim of this study is to investigate the performance of LRG1 for detection of EOC, including early stage EOC, and to evaluate if LRG1 can complement CA125 in order to improve EOC detection using two independent blinded sample sets.

Methods And Results: Serum LRG1 and CA125 were measured by immunoassays. All assays were performed blinded to clinical data. Using the two independent sample sets (156 participants for sample set 1, and 233 for sample set 2), LRG1 was differentially expressed in EOC cases as compared to healthy, surgical, and benign controls, and its performance was not affected by the conditions of blood collection. The areas under the ROC curve (AUC) for LRG1 in differentiating EOC cases from non-cases were 0.797 and 0.786 for sample set 1 and 2. For differentiating EOC cases from healthy controls, the AUC values for LRG1 were 0.792 and 0.794. At a fixed specificity of 95%, LRG1 detects 52%, and 53.5% of EOC cases from healthy controls for sample set 1 and 2. When combining LRG1 and CA125, the AUC value increased to 0.927, which was improved compared to CA125 (AUC=0.916) (p=0.008) alone in distinguishing EOC cases from non-cases. More importantly, LRG1 also showed potential performance in differentiating early stage EOC from non-cases with an AUC of 0.715 for sample set 1, and 0.690 for sample set 2. The combination of LRG1 and CA125 resulted in an AUC of 0.838, which outperforms CA125 (AUC=0.785) (p=0.018) in detecting early stage EOC cases from non-cases using the larger sample set.

Conclusions: LRG1 could be a useful biomarker alone or in combination with CA125 for the diagnosis of ovarian cancer.
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February 2016

Cancer Risk Awareness and Concern among Women with a Family History of Breast or Ovarian Cancer.

Behav Med 2016 3;42(1):18-28. Epub 2014 Nov 3.

a Fred Hutchinson Cancer Research Center and University of Washington.

Women with a documented deleterious mutation in BRCA1 or BRCA2 are at substantially elevated risk for ovarian cancer. To understand what percentage of women with high-risk family histories know their risk is elevated we surveyed 1,885 women with a high- or moderate-risk family history and no personal history of breast or ovarian cancer, and asked about their perceived risk of breast and ovarian cancer. Among high-risk women, fewer than 20% reported use of genetic counseling, and knowledge of elevated risk of ovarian cancer was low. Prior genetic counseling was associated with greater perceived risk for ovarian cancer. Results suggest that most high-risk women (>75%) do not know their risk for ovarian cancer. Identification of potentially high-risk women for referral to genetic counseling may improve informed ovarian cancer risk management.
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October 2016

Use of CA125 and HE4 serum markers to predict ovarian cancer in elevated-risk women.

Cancer Epidemiol Biomarkers Prev 2014 Jul 1;23(7):1383-93. Epub 2014 May 1.

Fred Hutchinson Cancer Research Center;

Background: Serum markers are used before pelvic imaging to improve specificity and positive predictive value (PPV) of ovarian cancer multimodal screening strategies.

Methods: We conducted a randomized controlled pilot trial to estimate surgical PPV of a "2 of 3 tests positive" screening rule, and to compare use of HE4 as a first-line (Arm 1) versus a second-line (Arm 2) screen, in women at high and elevated risk for epithelial ovarian cancer (EOC) at five study sites. Semiannual screening was offered to 208 women ages 25 to 80 years with deleterious BRCA germline mutations and to 834 women ages 35 to 80 years with pedigrees suggesting inherited susceptibility. Annual screening was offered to 130 women ages 45 to 80 years (Risk Group 3) with epidemiologic and serum marker risk factors. Rising marker levels were identified using the parametric empirical Bayes algorithm.

Results: Both strategies yielded surgical PPV above 25%. Protocol-indicated surgery was performed in 6 women, identifying two ovarian malignancies and yielding a surgical PPV in both arms combined of 33% (95% confidence interval: 4%-78%), 25% in Arm 1 and 50% in Arm 2. Surgical consultation was recommended for 37 women (26 in Arm 1 and 11 in Arm 2). On the basis of 12 women with at least 2 of 3 tests positive (CA125, HE4, or imaging), an intent-to-treat analysis yielded PPV of 14% in Arm 1 and 20% in Arm 2.

Conclusions: Positive screens were more frequent when HE4 was included in the primary screen.

Impact: HE4 may be useful as a confirmatory screen when rising CA125 is used alone as a primary screen.
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July 2014

JAK2 expression is associated with tumor-infiltrating lymphocytes and improved breast cancer outcomes: implications for evaluating JAK2 inhibitors.

Cancer Immunol Res 2014 Apr 15;2(4):301-6. Epub 2014 Jan 15.

Authors' Affiliations: Center for Computational Biology and Bioinformatics, Department of Electrical Engineering, Columbia University, New York, New York.

Janus kinase-2 (JAK2) supports breast cancer growth, and clinical trials testing JAK2 inhibitors are under way. In addition to the tumor epithelium, JAK2 is also expressed in other tissues including immune cells; whether the JAK2 mRNA levels in breast tumors correlate with outcomes has not been evaluated. Using a case-control design, JAK2 mRNA was measured in 223 archived breast tumors and associations with distant recurrence were evaluated by logistic regression. The frequency of correct pairwise comparisons of patient rankings based on JAK2 levels versus survival outcomes, the concordance index (CI), was evaluated using data from 2,460 patients in three cohorts. In the case-control study, increased JAK2 was associated with a decreasing risk of recurrence (multivariate P = 0.003, n = 223). Similarly, JAK2 was associated with a protective CI (<0.5) in the public cohorts: NETHERLANDS CI = 0.376, n = 295; METABRIC CI = 0.462, n = 1,981; OSLOVAL CI = 0.452, n = 184. Furthermore, JAK2 was strongly correlated with the favorable prognosis LYM metagene signature for infiltrating T cells (r = 0.5; P < 2 × 10(-16); n = 1,981) and with severe lymphocyte infiltration (P = 0.00003, n = 156). Moreover, the JAK1/2 inhibitor ruxolitinib potently inhibited the anti-CD3-dependent production of IFN-γ, a marker of the differentiation of Th cells along the tumor-inhibitory Th1 pathway. The potential for JAK2 inhibitors to interfere with the antitumor capacities of T cells should be evaluated.
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April 2014

Longitudinal screening algorithm that incorporates change over time in CA125 levels identifies ovarian cancer earlier than a single-threshold rule.

J Clin Oncol 2013 Jan 17;31(3):387-92. Epub 2012 Dec 17.

Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, M2-B230, Seattle, WA 98104, USA.

Purpose: Longitudinal algorithms incorporate change over time in biomarker levels to individualize screening decision rules. Compared with a single-threshold (ST) rule, smaller deviations from baseline biomarker levels are required to signal disease. We demonstrated improvement in ovarian cancer early detection by using a longitudinal algorithm to monitor annual CA125 levels.

Patients And Methods: We retrospectively evaluated serial preclinical serum CA125 values measured annually in 44 incident ovarian cancer cases identified from participants in the PLCO (Prostate Lung Colorectal and Ovarian) Cancer Screening Trial to determine how frequently and to what extent the parametric empirical Bayes (PEB) longitudinal screening algorithm identifies ovarian cancer earlier than an ST rule.

Results: The PEB algorithm detected ovarian cancer earlier than an ST rule in a substantial proportion of cases. At 99% specificity, which corresponded to the ST-rule CA125 cutoff ≥ 35 U/mL that was used in the PLCO trial, 20% of cases were identified earlier by using the PEB algorithm. Among these cases, the PEB signaled abnormal CA125 values, on average, 10 months earlier and at a CA125 concentration 42% lower (20 U/mL) than the ST-rule cutoff. The proportion of cases detected earlier by the PEB algorithm and the earliness of detection increased as the specificity of the screening rule was reduced.

Conclusion: The PEB longitudinal algorithm identifies ovarian cancer earlier and at lower biomarker concentrations than an ST screening algorithm adjusted to the same specificity. Longitudinal biomarker assessment by using the PEB algorithm may have application for screening other solid tumors in which biomarkers are available.
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January 2013

Interpretation of single and serial measures of HE4 and CA125 in asymptomatic women at high risk for ovarian cancer.

Cancer Epidemiol Biomarkers Prev 2012 Nov 7;21(11):2087-94. Epub 2012 Sep 7.

Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, M2-B230, P.O. Box 19024, Seattle, WA 98109, USA.

Background: Human epididymis protein 4 (HE4) is approved for clinical use with CA125 to predict epithelial ovarian cancer in women with a pelvic mass or in remission after chemotherapy. Previously reported reference ranges for HE4 are inconsistent.

Methods: We report positivity thresholds yielding 90%, 95%, 98%, and 99% specificity for age-defined populations of healthy women for HE4, CA125, and Risk of Ovarian Malignancy Algorithm (ROMA), a weighted average of HE4 and CA125. HE4 and CA125 were measured in 1,780 samples from 778 healthy women aged >25 years with a documented deleterious mutation, or aged >35 years with a significant family history. Effects on marker levels of a woman's age, ethnicity, and epidemiologic characteristics were estimated, as were the population-specific means, variances, and within- and between-woman variances used to generate longitudinal screening algorithms for these markers.

Results: CA125 levels were lower with Black ethnicity (P = 0.008). Smoking was associated with higher HE4 (P = 0.007) and ROMA (P < 0.019). Continuous oral contraceptive use decreased levels of CA125 (P = 0.041), and ROMA (P = 0.12). CA125 was lower in women age ≥55, and HE4 increased with age (P < 0.01), particularly among women age ≥55.

Conclusions: Because of the strong effect of age on HE4, thresholds for HE4 are best defined for women of specific ages. Age-specific population thresholds for HE4 for 95% specificity ranged from 41.4 pmol/L for women age 30 to 82.1 pmol/L for women age 80.

Impact: Incorporation of serial marker values from screening history reduces personalized thresholds for CA125 and HE4 but is inappropriate for ROMA.
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November 2012

Impact of screening test performance and cost on mortality reduction and cost-effectiveness of multimodal ovarian cancer screening.

Cancer Prev Res (Phila) 2012 Aug 2;5(8):1015-24. Epub 2012 Jul 2.

Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98104, USA.

Ongoing ovarian cancer screening trials are investigating the efficacy of a two-step screening strategy using currently available blood and imaging tests [CA125 and transvaginal sonography (TVS)]. Concurrently, efforts to develop new biomarkers and imaging tests seek to improve screening performance beyond its current limits. This study estimates the mortality reduction, years of life saved, and cost-effectiveness achievable by annual multimodal screening using increasing CA125 to select women for TVS, and predicts improvements achievable by replacing currently available screening tests with hypothetical counterparts with better performance characteristics. An existing stochastic microsimulation model is refined and used to screen a virtual cohort of 1 million women from ages 45 to 85 years. Each woman is assigned a detailed disease course and screening results timeline. The preclinical behavior of CA125 and TVS is simulated using empirical data derived from clinical trials. Simulations in which the disease incidence and performance characteristics of the screening tests are independently varied are conducted to evaluate the impact of these factors on overall screening performance and costs. Our results show that when applied to women at average risk, annual screening using increasing CA125 to select women for TVS achieves modest mortality reduction (~13%) and meets currently accepted cost-effectiveness guidelines. Screening outcomes are relatively insensitive to second-line test performance and costs. Identification of a first-line test that does substantially better than CA125 and has similar costs is required for screening to reduce ovarian mortality by at least 25% and be reasonably cost-effective.
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August 2012

Evaluation of ovarian cancer remission markers HE4, MMP7 and Mesothelin by comparison to the established marker CA125.

Gynecol Oncol 2012 Apr 7;125(1):65-9. Epub 2011 Dec 7.

Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.

Objective: Evaluate and compare the effectiveness of CA125, HE4, Mesothelin and MMP7 marker levels to monitor ovarian cancer patients after surgery and chemotherapy. Evaluate the lead time of a rise of marker levels before recurrence.

Methods: The study consists of 23 patients with advanced stage ovarian/fallopian tube cancer. Blood was drawn after front line surgery and chemotherapy treatment and at 3 month intervals thereafter. One patient had chemoresistant disease, two patients remained in remission and 20 patients had recurring disease and were used for marker evaluation.

Results: In five patients HE4 was the only marker to elevate before recurrence with a lead time of up to 4½ months including one patient who did not have a CA125 response at all. In a further two patients, HE4 increased before CA125 did. In four of these seven patients, HE4 levels were consistently at or above threshold during remission when both CA125 and imaging results were negative. MMP7 elevated before recurrence in one patient who was negative for the other markers. Mesothelin elevated in two patients who were also positive for CA125 and HE4.

Conclusions: HE4 can predict ovarian cancer recurrence earlier than CA125 and it can be elevated in patients that do not express CA125 at sufficient levels to make a clinical decision. MMP7 and Mesothelin have lower potential as markers for ovarian cancer recurrence to complement CA125. A failure of HE4 levels to normalize at completion of standard therapy may indicate a poor prognosis.
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April 2012

Potential role of HE4 in multimodal screening for epithelial ovarian cancer.

J Natl Cancer Inst 2011 Nov 14;103(21):1630-4. Epub 2011 Sep 14.

Molecular Diagnostics Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA.

In screening for epithelial ovarian cancer, unnecessary surgery can be reduced by limiting use of transvaginal ultrasound (TVU) to women with increasing CA125 serum levels. Replacing or augmenting TVU with measurement of a serum marker specific for malignancy might further improve screening performance. Serum samples from 112 invasive ovarian cancer patients and 706 matched control subjects from the Prostate, Lung, Colorectal, and Ovarian trial were used to evaluate human epididymis protein 4 (HE4), mesothelin, matrix metalloproteinase 7 (MMP7), SLPI, Spondin2, and insulin-like growth factor binding protein 2 (IGFBP2) for their potential use in screening. TVU results were available for a subset of 84 patients and 516 control subjects used to compare the best marker with TVU. HE4 was found to perform better than TVU as a second-line screen, confirming 27 of 39 cancers with increasing CA125 serum levels compared with 17 cancers confirmed by TVU (P = .03). Serum HE4 levels were found to increase with age and smoking status, suggesting that a longitudinal algorithm might improve its performance.
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November 2011

Irradiation effect after mastectomy on breast cancer recurrence in patients presenting with locally advanced disease.

Am J Surg 2011 May;201(5):605-10

Department of Surgery, Swedish Cancer Institute, Swedish Medical Center, Seattle, WA 98104, USA.

Background: Current guidelines recommend postmastectomy irradiation (PMI) for patients with tumors >5 cm and/or ≥4 positive lymph nodes. This study evaluates the effect of PMI on recurrence and survival within tumor size and node status groups.

Methods: Locoregional and distant recurrences and survival for different tumor and treatment characteristics were analyzed in 2,797 patients with invasive breast cancer treated with mastectomy.

Results: Tumor size, positive nodes, extranodal extension, lymphatic/vascular invasion, estrogen receptor/progesterone negative, HER-2 positive, and high grade were associated with significantly increased recurrence. In patients with ≥4 positive nodes and patients with tumors >5 cm and positive nodes, PMI decreased local and distant recurrence (overall 53% vs 24%, P < .001) and increased disease-free survival (P < .001) but not overall survival. In patients with less disease, a benefit from PMI irradiation could not be identified.

Conclusions: PMI is indicated for patients with ≥4 positive nodes or patients with tumors >5 cm and positive nodes.
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May 2011

Assessing lead time of selected ovarian cancer biomarkers: a nested case-control study.

J Natl Cancer Inst 2010 Jan 30;102(1):26-38. Epub 2009 Dec 30.

Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, PO Box 19024, M3-A410, Seattle, WA 98109-1024, USA.

Background: CA125, human epididymis protein 4 (HE4), mesothelin, B7-H4, decoy receptor 3 (DcR3), and spondin-2 have been identified as potential ovarian cancer biomarkers. Except for CA125, their behavior in the prediagnostic period has not been evaluated.

Methods: Immunoassays were used to determine concentrations of CA125, HE4, mesothelin, B7-H4, DcR3, and spondin-2 proteins in prediagnostic serum specimens (1-11 samples per participant) that were contributed 0-18 years before ovarian cancer diagnosis from 34 patients with ovarian cancer (15 with advanced-stage serous carcinoma) and during a comparable time interval before the reference date from 70 matched control subjects who were participating in the Carotene and Retinol Efficacy Trial. Lowess curves were fit to biomarker levels in cancer patients and control subjects separately to summarize mean levels over time. Receiver operating characteristic curves were plotted, and area-under-the curve (AUC) statistics were computed to summarize the discrimination ability of these biomarkers by time before diagnosis.

Results: Smoothed mean concentrations of CA125, HE4, and mesothelin (but not of B7-H4, DcR3, and spondin-2) began to increase (visually) in cancer patients relative to control subjects approximately 3 years before diagnosis but reached detectable elevations only within the final year before diagnosis. In descriptive receiver operating characteristic analyses, the discriminatory power of these biomarkers was limited (AUC statistics range = 0.56-0.75) but showed increasing accuracy with time approaching diagnosis (eg, AUC statistics for CA125 were 0.57, 0.68, and 0.74 for > or = 4, 2-4, and <2 years before diagnosis, respectively).

Conclusion: Serum concentrations of CA125, HE4, and mesothelin may provide evidence of ovarian cancer 3 years before clinical diagnosis, but the likely lead time associated with these markers appears to be less than 1 year.
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January 2010

Integrated proteomic analysis of human cancer cells and plasma from tumor bearing mice for ovarian cancer biomarker discovery.

PLoS One 2009 Nov 19;4(11):e7916. Epub 2009 Nov 19.

Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America.

Background: The complexity of the human plasma proteome represents a substantial challenge for biomarker discovery. Proteomic analysis of genetically engineered mouse models of cancer and isolated cancer cells and cell lines provide alternative methods for identification of potential cancer markers that would be detectable in human blood using sensitive assays. The goal of this work is to evaluate the utility of an integrative strategy using these two approaches for biomarker discovery.

Methodology/principal Findings: We investigated a strategy that combined quantitative plasma proteomics of an ovarian cancer mouse model with analysis of proteins secreted or shed by human ovarian cancer cells. Of 106 plasma proteins identified with increased levels in tumor bearing mice, 58 were also secreted or shed from ovarian cancer cells. The remainder consisted primarily of host-response proteins. Of 25 proteins identified in the study that were assayed, 8 mostly secreted proteins common to mouse plasma and human cancer cells were significantly upregulated in a set of plasmas from ovarian cancer patients. Five of the eight proteins were confirmed to be upregulated in a second independent set of ovarian cancer plasmas, including in early stage disease.

Conclusions/significance: Integrated proteomic analysis of cancer mouse models and human cancer cell populations provides an effective approach to identify potential circulating protein biomarkers.
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November 2009

Influence of ovarian cancer risk status on the diagnostic performance of the serum biomarkers mesothelin, HE4, and CA125.

Cancer Epidemiol Biomarkers Prev 2009 May;18(5):1365-72

University of Washington, Seattle, WA 98195, USA.

Objective: To evaluate the effect of ovarian cancer risk on the performance of the serum biomarkers mesothelin, human epididymis protein 4 (HE4), and CA125.

Methods: We measured mesothelin, HE4, and CA125 levels from women with invasive ovarian cancer (n = 143), benign gynecologic conditions (n = 124), and controls (n = 344). Demographic, epidemiologic, reproductive, medical, and family history data were collected using a standardized questionnaire. Pedigree and BRCA 1/2 test results were used to stratify women into average and high-risk groups. The diagnostic accuracy of each biomarker was characterized using receiver operating characteristic curve methods.

Results: Baseline characteristics did not vary by risk or case status. The distribution of stage and histology was similar in average and high-risk women. All three markers discriminated ovarian cancer cases from risk-matched healthy and benign controls. Marker performance did not vary by risk status. The sensitivity at 95% specificity for discriminating cases from risk-matched healthy control women in the average and high-risk groups, respectively, was 53.9% and 39.0% for mesothelin, 80.4% and 87.8% for HE4, and 79.4% and 82.9% for CA125. The performance of the markers was not as robust when cases were compared with benign controls. Area under the curve values for cases versus healthy and benign controls did not vary by risk status.

Conclusions: The ability of serum mesothelin, HE4, and CA 125 levels to discriminate ovarian cancer cases from healthy and benign controls is not influenced by risk status. Our findings support the pursuit of additional studies evaluating the early detection potential of these markers in high-risk populations.
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May 2009

Effects of personal characteristics on serum CA125, mesothelin, and HE4 levels in healthy postmenopausal women at high-risk for ovarian cancer.

Cancer Epidemiol Biomarkers Prev 2008 Sep;17(9):2480-7

Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA.

Objective: To evaluate if serum levels of candidate ovarian cancer biomarkers vary with individual characteristics of healthy women who are likely candidates for an ovarian cancer screening program.

Methods: We analyzed serum CA125, mesothelin, and HE4 levels in a sample of 155 healthy postmenopausal women at increased risk for developing ovarian cancer based on personal and family cancer history. Information on reproductive, family and medical histories, lifestyle factors, and anthropometry was collected by self-report. Twenty-two factors were examined using univariate and multiple linear regression models for the three biomarker levels.

Results: In the multivariate models, CA125 levels were significantly higher in women who had used talcum powder (P = 0.02) and were lower in women who were parous (P = 0.05). Mesothelin levels were significantly higher in older women (P = 0.01) and lower in heavier women (P = 0.03). HE4 levels were higher in older women (P = 0.001) and in women who began menstruating at an older age (P = 0.03).

Conclusions: CA125, mesothelin, and HE4 levels in healthy, postmenopausal women at increased risk for ovarian cancer are significantly associated with a few ovarian cancer risk factors. Since the effects of these personal characteristics on these serum markers are not large, their incorporation in screening algorithms may be unnecessary. This is true especially if a longitudinal algorithm is used because the marker level at the previous screen reflects personal characteristics such as age, body mass index, and age of menarche. Understanding the influence of personal factors on levels of novel early detection markers in healthy, unaffected women may have clinical utility in interpreting biomarker levels.
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September 2008

Systematic evaluation of candidate blood markers for detecting ovarian cancer.

PLoS One 2008 Jul 9;3(7):e2633. Epub 2008 Jul 9.

Canary Foundation, Scientific Programs, San Jose, California, United States of America.

Background: Epithelial ovarian cancer is a significant cause of mortality both in the United States and worldwide, due largely to the high proportion of cases that present at a late stage, when survival is extremely poor. Early detection of epithelial ovarian cancer, and of the serous subtype in particular, is a promising strategy for saving lives. The low prevalence of ovarian cancer makes the development of an adequately sensitive and specific test based on blood markers very challenging. We evaluated the performance of a set of candidate blood markers and combinations of these markers in detecting serous ovarian cancer.

Methods And Findings: We selected 14 candidate blood markers of serous ovarian cancer for which assays were available to measure their levels in serum or plasma, based on our analysis of global gene expression data and on literature searches. We evaluated the performance of these candidate markers individually and in combination by measuring them in overlapping sets of serum (or plasma) samples from women with clinically detectable ovarian cancer and women without ovarian cancer. Based on sensitivity at high specificity, we determined that 4 of the 14 candidate markers--MUC16, WFDC2, MSLN and MMP7--warrant further evaluation in precious serum specimens collected months to years prior to clinical diagnosis to assess their utility in early detection. We also reported differences in the performance of these candidate blood markers across histological types of epithelial ovarian cancer.

Conclusions: By systematically analyzing the performance of candidate blood markers of ovarian cancer in distinguishing women with clinically apparent ovarian cancer from women without ovarian cancer, we identified a set of serum markers with adequate performance to warrant testing for their ability to identify ovarian cancer months to years prior to clinical diagnosis. We argued for the importance of sensitivity at high specificity and of magnitude of difference in marker levels between cases and controls as performance metrics and demonstrated the importance of stratifying analyses by histological type of ovarian cancer. Also, we discussed the limitations of studies (like this one) that use samples obtained from symptomatic women to assess potential utility in detection of disease months to years prior to clinical detection.
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July 2008

Use of yeast-secreted in vivo biotinylated recombinant antibodies (Biobodies) in bead-based ELISA.

Clin Cancer Res 2008 May;14(9):2647-55

School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 96104-6069, USA.

Purpose: To measure circulating antigens, sandwich ELISA assays require two complementary affinity reagents. Mouse monoclonal antibodies (mAb) and polyclonal antibodies (pAb) are commonly used, but because their production is lengthy and costly, recombinant antibodies are emerging as an attractive alternative.

Experimental Design: We developed a new class of recombinant antibodies called biobodies (Bb) and compared them to mAb for use in serodiagnosis. Bbs were secreted biotinylated in vivo by diploid yeast and used as affinity reagents after Ni purification. Bead-based assays for HE4 and mesothelin were developed using Bbs in combination with pAbs (Bb/pAb assays). To assess precision, reproducibility studies were done using four runs of 16 replicates at six analyte levels for each marker. Pearson correlations and receiver-operator characteristic analyses were done in 214 patient serum samples to directly compare the Bb/pAb assays to mAb assays. Diagnostic performance of the Bb/pAb assay was further assessed in an expanded set of 336 ovarian cancer cases and controls.

Results: On average across analyte levels, Bb/pAb assays yielded within-run and between-run coefficients of variations of 11.7 and 23.8, respectively, for HE4 and 14.0 and 14.5, respectively, for mesothelin. In the subset (n = 214), Pearson correlations of 0.95 for HE4 and 0.92 for mesothelin were observed between mAb and Bb/pAb assays. The area under the curves for the mAb and Bb/pAb assays were not significantly different for HE4 (0.88 and 0.84, respectively; P = 0.20) or mesothelin (0.74 and 0.72, respectively; P = 0.38).

Conclusion: Yeast-secreted Bbs can be used reliably in cost-effective yet highly sensitive bead-based assays for use in large validation studies.
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May 2008

Effects of blood collection conditions on ovarian cancer serum markers.

PLoS One 2007 Dec 5;2(12):e1281. Epub 2007 Dec 5.

Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America.

Background: Evaluating diagnostic and early detection biomarkers requires comparing serum protein concentrations among biosamples ascertained from subjects with and without cancer. Efforts are generally made to standardize blood processing and storage conditions for cases and controls, but blood sample collection conditions cannot be completely controlled. For example, blood samples from cases are often obtained from persons aware of their diagnoses, and collected after fasting or in surgery, whereas blood samples from some controls may be obtained in different conditions, such as a clinic visit. By measuring the effects of differences in collection conditions on three different markers, we investigated the potential of these effects to bias validation studies.

Methodology And Principle Findings: We analyzed serum concentrations of three previously studied putative ovarian cancer serum biomarkers-CA 125, Prolactin and MIF-in healthy women, women with ovarian cancer undergoing gynecologic surgery, women undergoing surgery for benign ovary pathology, and women undergoing surgery with pathologically normal ovaries. For women undergoing surgery, a blood sample was collected either in the clinic 1 to 39 days prior to surgery, or on the day of surgery after anesthesia was administered but prior to the surgical procedure, or both. We found that one marker, prolactin, was dramatically affected by collection conditions, while CA 125 and MIF were unaffected. Prolactin levels were not different between case and control groups after accounting for the conditions of sample collection, suggesting that sample ascertainment could explain some or all of the previously reported results about its potential as a biomarker for ovarian cancer.

Conclusions: Biomarker validation studies should use standardized collection conditions, use multiple control groups, and/or collect samples from cases prior to influence of diagnosis whenever feasible to detect and correct for potential biases associated with sample collection.
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December 2007