Peter F. Rambau

An Immunohistochemical Algorithm for Ovarian Carcinoma Typing.

There are 5 major histotypes of ovarian carcinomas. Diagnostic typing criteria have evolved over time, and past cohorts may be misclassified by current standards. Our objective was to reclassify the recently assembled Canadian Ovarian Experimental Unified Resource and the Alberta Ovarian Tumor Type cohorts using immunohistochemical (IHC) biomarkers and to develop an IHC algorithm for ovarian carcinoma histotyping. A total of 1626 ovarian carcinoma samples from the Canadian Ovarian Experimental Unified Resource and the Alberta Ovarian Tumor Type were subjected to a reclassification by comparing the original with the predicted histotype. Histotype prediction was derived from a nominal logistic regression modeling using a previously reclassified cohort (N=784) with the binary input of 8 IHC markers. Cases with discordant original or predicted histotypes were subjected to arbitration. After reclassification, 1762 cases from all cohorts were subjected to prediction models (&khgr;2 Automatic Interaction Detection, recursive partitioning, and nominal logistic regression) with a variable IHC marker input. The histologic type was confirmed in 1521/1626 (93.5%) cases of the Canadian Ovarian Experimental Unified Resource and the Alberta Ovarian Tumor Type cohorts. The highest misclassification occurred in the endometrioid type, where most of the changes involved reclassification from endometrioid to high-grade serous carcinoma, which was additionally supported by mutational data and outcome. Using the reclassified histotype as the endpoint, a 4-marker prediction model correctly classified 88%, a 6-marker 91%, and an 8-marker 93% of the 1762 cases. This study provides statistically validated, inexpensive IHC algorithms, which have versatile applications in research, clinical practice, and clinical trials.

Dose-Response Association of CD8+ Tumor-Infiltrating Lymphocytes and Survival Time in High-Grade Serous Ovarian Cancer.

Importance Cytotoxic CD8+ tumor-infiltrating lymphocytes (TILs) participate in immune control of epithelial ovarian cancer; however, little is known about prognostic patterns of CD8+ TILs by histotype and in relation to other clinical factors. Objective To define the prognostic role of CD8+ TILs in epithelial ovarian cancer. Design, Setting, and Participants This was a multicenter observational, prospective survival cohort study of the Ovarian Tumor Tissue Analysis Consortium. More than 5500 patients, including 3196 with high-grade serous ovarian carcinomas (HGSOCs), were followed prospectively for over 24 650 person-years. Exposures Following immunohistochemical analysis, CD8+ TILs were identified within the epithelial components of tumor islets. Patients were grouped based on the estimated number of CD8+ TILs per high-powered field: negative (none), low (1-2), moderate (3-19), and high (≥20). CD8+ TILs in a subset of patients were also assessed in a quantitative, uncategorized manner, and the functional form of associations with survival was assessed using penalized B-splines. Main Outcomes and Measures Overall survival time. Results The final sample included 5577 women; mean age at diagnosis was 58.4 years (median, 58.2 years). Among the 5 major invasive histotypes, HGSOCs showed the most infiltration. CD8+ TILs in HGSOCs were significantly associated with longer overall survival; median survival was 2.8 years for patients with no CD8+ TILs and 3.0 years, 3.8 years, and 5.1 years for patients with low, moderate, or high levels of CD8+ TILs, respectively (P value for trendu2009=u20094.2u2009×u200910−16). A survival benefit was also observed among women with endometrioid and mucinous carcinomas, but not for those with the other histotypes. Among HGSOCs, CD8+ TILs were favorable regardless of extent of residual disease following cytoreduction, known standard treatment, and germline BRCA1 pathogenic mutation, but were not prognostic for BRCA2 mutation carriers. Evaluation of uncategorized CD8+ TIL counts showed a near-log-linear functional form. Conclusions and Relevance This study demonstrates the histotype-specific nature of immune infiltration and provides definitive evidence for a dose-response relationship between CD8+ TILs and HGSOC survival. That the extent of infiltration is prognostic, not merely its presence or absence, suggests that understanding factors that drive infiltration will be the key to unraveling outcome heterogeneity in this cancer.

Significant frequency of MSH2/MSH6 abnormality in ovarian endometrioid carcinoma supports histotype-specific Lynch syndrome screening in ovarian carcinomas

Lynch syndrome screening in ovarian carcinoma is controversial. The aim of this study was to assess the frequency of deficient mismatch repair (dMMR) protein in a retrospective cohort enriched for non‐high‐grade serous carcinomas and its association with outcome within histological types.

Progesterone receptor expression is associated with longer overall survival within high-grade histotypes of endometrial carcinoma: A Canadian high risk endometrial cancer consortium (CHREC) study

OBJECTIVEnTo assess the association of hormone receptor expression with outcome in high-grade endometrial carcinomas.nnnMETHODSnThis study included three sites participating in the Canadian High Risk Endometrial Cancer (CHREC) consortium. Sections from tissue microarrays containing cases with a diagnosis of endometrioid grade 3 (EC3) and endometrial serous carcinoma (ESC) were assessed for estrogen (ER) and progesterone receptor (PR) expression by immunohistochemistry. Expression was considered present if >1% of tumor cell nuclei were labeled. Associations with overall survival were assessed.nnnRESULTSnER expression was present in 168/216 (78%) of EC3 and 124/192 (65%) of ESC. PR expression was present in 148/212 (70%) of EC3 and 83/196 (42%) of ESC. PR expression was significantly associated with favorable overall survival in EC3 and ESC (log rank, p=0.018 and p=0.0024) but ER expression was not. PR expression was significantly associated with favorable overall survival in EC3 independent of age, stage, center and lymph-vascular invasion (hazard ratio=0.457, 95% CI 0.257-0.811, p=0.0075) as well as in stage I and II ESC (hazard ratio=0.266, 95% CI 0.094-0.750, p=0.0123).nnnCONCLUSIONnOur data provide support for the assessment of the PR expression status in EC3 and ESC. Future work will be required to determine how PR expression may be incorporated into management of patients with EC3 and ESC.

Morphologic Reproducibility, Genotyping, and Immunohistochemical Profiling Do Not Support a Category of Seromucinous Carcinoma of the Ovary

The 2014 World Health Organization Classification of Tumors of Female Reproductive Organs endorsed the new category of seromucinous carcinoma, a neoplasm that exhibits morphologic and immunophenotypic overlap with other histotypes of ovarian carcinoma. The goal of this study was to determine whether seromucinous carcinoma was a distinct histotype by assessing its diagnostic reproducibility and comparing its molecular composition to the 5 major histotypes of ovarian carcinoma. Thirty-two tumors diagnosed as seromucinous carcinomas from 2 centers were studied. Eighteen cases were randomly selected for a review set comprising a total of 50 ovarian carcinomas of various histotypes. Morphologic histotype was independently assessed by 4 pathologists. For the 32 seromucinous carcinomas, a histotype-specific immunophenotype was assigned using a diagnostic immunohistochemical panel. Histotype-specific genotype was assigned using a combination of immunohistochemistry and targeted next-generation sequencing for somatic mutations, including genes recurrently mutated in ovarian carcinomas. There was low to modest agreement between pathologists with the reference diagnosis of seromucinous carcinoma, ranging from 39% to 56% for the 4 observers. The immunophenotype was not unique but overlapped predominantly with endometrioid and to a lesser extent with mucinous and low-grade serous carcinoma. Genomic and immunohistochemical alterations were detected in a number of target genes, including KRAS (70%), PIK3CA (37%), PTEN (19%), and ARID1A (16%); no CTNNB1 mutations were identified. Nine cases (30%) harbored concurrent KRAS/PIK3CA mutations. An endometrioid genotype was assigned to 19 cases, a low-grade serous genotype to 9, and a mucinous genotype to 1 and 3 cases were uninformative. Integrating morphology, immunophenotype, and genotyping resulted in reclassifying the seromucinous carcinomas to endometrioid 23/32 (72%), low-grade serous 8/32 (25%), and mucinous 1/32 (3%). The morphologic diagnosis of seromucinous carcinomas is not very reliable and it does not exhibit a distinct immunophenotype or genotype. The molecular features overlap mostly with endometrioid and low-grade serous carcinomas. Our data suggest the category of seromucinous carcinoma be discontinued as ancillary molecular tests can assign cases to one of the major histotypes.

Homologous Recombination DNA Repair Pathway Disruption and Retinoblastoma Protein Loss Are Associated with Exceptional Survival in High-Grade Serous Ovarian Cancer.

Purpose: Women with epithelial ovarian cancer generally have a poor prognosis; however, a subset of patients has an unexpected dramatic and durable response to treatment. We sought to identify clinical, pathological, and molecular determinants of exceptional survival in women with high-grade serous cancer (HGSC), a disease associated with the majority of ovarian cancer deaths. Experimental Design: We evaluated the histories of 2,283 ovarian cancer patients and, after applying stringent clinical and pathological selection criteria, identified 96 with HGSC that represented significant outliers in terms of treatment response and overall survival. Patient samples were characterized immunohistochemically and by genome sequencing. Results: Different patterns of clinical response were seen: long progression-free survival (Long-PFS), multiple objective responses to chemotherapy (Multiple Responder), and/or greater than 10-year overall survival (Long-Term Survivors). Pathogenic germline and somatic mutations in genes involved in homologous recombination (HR) repair were enriched in all three groups relative to a population-based series. However, 29% of 10-year survivors lacked an identifiable HR pathway alteration, and tumors from these patients had increased Ki-67 staining. CD8+ tumor-infiltrating lymphocytes were more commonly present in Long-Term Survivors. RB1 loss was associated with long progression-free and overall survival. HR deficiency and RB1 loss were correlated, and co-occurrence was significantly associated with prolonged survival. Conclusions: There was diversity in the clinical trajectory of exceptional survivors associated with multiple molecular determinants of exceptional outcome in HGSC patients. Concurrent HR deficiency and RB1 loss were associated with favorable outcomes, suggesting that co-occurrence of specific mutations might mediate durable responses in such patients. Clin Cancer Res; 24(3); 569–80. ©2017 AACR. See related commentary by Peng and Mills, p. 508

Molecular alterations in indolent, aggressive and recurrent ovarian low-grade serous carcinoma.

The clinical courses of patients with low‐grade serous carcinoma (LGSC) can be substantially different. The purpose of this study was to explore whether molecular or pathological features could identify patients who follow a more aggressive course.

Synchronous endometrial and ovarian carcinomas: predictors of risk and associations with survival and tumor expression profiles

PurposeSynchronous endometrial and ovarian tumors (SEOs) are diagnosed in 10% of ovarian cancer patients. We examined predictors of SEOs, evaluated associations of SEOs with survival and characterized ovarian tumor profiles using immunohistochemistry.MethodsWe included patients with endometrioid (nu2009=u2009180) and clear cell (nu2009=u2009165) ovarian carcinoma identified from the Alberta Cancer Registry between 1979 and 2010 for whom we abstracted medical records and constructed tumor tissue microarrays (TMAs). A concurrent diagnosis of endometrial cancer was obtained from the medical chart. We used unconditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) and Cox proportional hazards models to estimate hazard ratios (HRs) and 95% CIs. Protein expression in ovarian tumors of patients with and without SEOs was evaluated using Fisher’s exact test.ResultsComparing 52 patients with SEO tumors to 293 patients with endometrioid or clear cell ovarian carcinomas, endometriosis at the ovary (ORu2009=u20090.45, 95% CIu2009=u20090.23–0.87, pu2009=u20090.02) was the strongest predictor of decreased risk in multivariable models. Premenopausal status (ORu2009=u20092.17, 95% CIu2009=u20090.92–5.13, pu2009=u20090.08) and lower pre-treatment CA125 levels (ORu2009=u20090.17, 95% CIu2009=u20090.02–1.32, pu2009=u20090.09) showed weaker associations. There were no significant differences in survival between patients with or without SEO tumors. More patients with SEO tumors compared to endometrioid ovarian carcinoma were deficient in MLH1, PMS2 and PTEN (pu2009≤u20090.03).ConclusionsEndometriosis may not be the mechanism by which SEO cancers arise. Altered tumor oncoprotein expression between women with and without SEOs indicates important biological differences although this did not translate into prognostic differences.

Immunohistochemical Profiling of Endometrial Serous Carcinoma.

Endometrial serous carcinoma (ESC) is an aggressive neoplasm mainly seen in older women. The objective of this study was to refine immunohistochemical (IHC) panels for the differential diagnoses against endometrial endometrioid grade 3 (EC3), endometrial clear cell, and ovarian high-grade serous carcinoma as well as exploring the prognostic role of selected IHC markers. Fifty-two ESC from a single institution were assessed for 20 IHC markers, including ARID1A, CCNE1, CDKN2A, ERBB2, ESR1, HNF1B, FBXW7, IGF2BP3, MLH1, MSH2, MSH6, NAPSA, PAX8, PGR, PMS2, PTEN, TFF3, TP53, VIM, and WT1. ERBB2 chromogenic in situ hybridization was evaluated on tissue microarrays. Statistical analysis was performed. All ESC showed aberrant TP53, normal mismatch repair protein, and retained ARID1A and PTEN expression. ESR1 expression was present in 80% of ESC. A combination of TP53, PTEN, and CDKN2A had a sensitivity of 93.6% [95% confidence interval (CI), 84%–98%] and specificity of 87.8% (95% CI, 75%–95%) for ESC versus EC3. A combination of NAPSA and ESR1 had a sensitivity of 97.9% (95% CI, 89%–99%) and specificity of 72.2% (95% CI, 46%–90%) for ESC versus clear cell carcinoma. Absence of WT1 alone had a sensitivity of 66.0% (95% CI, 51%–79%) and specificity of 98.0% (95% CI, 94%–99%) for ESC versus ovarian high-grade serous carcinoma. Among all 52 ESCs, ERBB2 amplification was present in 23%, FBXW7 expression was absent in 10%, and CCNE1 was overexpressed in 59%, however, none were associated with prognosis. Our data support the value of IHC marker panels for histotyping of high-grade endometrial carcinomas.

Association of Hormone Receptor Expression with Survival in Ovarian Endometrioid Carcinoma: Biological Validation and Clinical Implications

This paper aims to validate whether hormone receptor expression is associated with longer survival among women diagnosed with ovarian endometrioid carcinoma (EC), and whether it identifies patients with stage IC/II tumors with excellent outcome that could be spared from toxic chemotherapy. Expression of estrogen receptor (ER) and progesterone receptor (PR) was assessed on 182 EC samples represented on tissue microarrays using the Alberta Ovarian Tumor Type (AOVT) cohort. Statistical analyses were performed to test for associations with ovarian cancer specific survival. ER or PR expression was present in 87.3% and 86.7% of cases, respectively, with co-expression present in 83.0%. Expression of each of the hormonal receptors was significantly higher in low-grade tumors and tumors with squamous differentiation. Expression of ER (Hazard Ratio (HR) = 0.18, 95% confidence interval 0.08–0.42, p = 0.0002) and of PR (HR = 0.22, 95% confidence interval 0.10–0.53, p = 0.0011) were significantly associated with longer ovarian cancer specific survival adjusted for age, grade, treatment center, stage, and residual disease. However, the five-year ovarian cancer specific survival among women with ER positive stage IC/II EC was 89.0% (standard error 3.3%) and for PR positive tumors 89.9% (standard error 3.2%), robustly below the 95% threshold where adjuvant therapy could be avoided. We validated the association of hormone receptor expression with ovarian cancer specific survival independent of standard predictors in an independent sample set of EC. The high ER/PR co-expression frequency and the survival difference support further testing of the efficacy of hormonal therapy in hormone receptor-positive ovarian EC. The clinical utility to identify a group of women diagnosed with EC at stage IC/II that could be spared from adjuvant therapy is limited.