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

High-grade Endometrioid Carcinoma of the Ovary: A Clinicopathologic Study of 30 Cases

Although infrequently encountered, the diagnosis of ovarian high-grade endometrioid carcinoma remains a diagnostic challenge with potential consequences for targeted therapies and genetic counselling. We studied the clinical, morphologic, and immunohistochemical features of ovarian high-grade endometrioid carcinomas and their diagnostic reproducibility compared with tuboovarian high-grade serous carcinomas. Thirty cases confirmed as International Federation of Gynecology and Obstetrics grade 3 endometrioid carcinomas were identified from 182 ovarian endometrioid carcinomas diagnosed in Alberta, Canada, between 1978 and 2010, from the population-based Alberta Ovarian Tumor Types cohort. Cases of lower grade endometrioid and high-grade serous carcinoma served for comparison. Ten immunohistochemical markers were assessed on tissue microarrays. Clinical data were abstracted and survival analyses performed using Cox regression. Interobserver reproducibility for histologic type was assessed using 1 representative hematoxylin and eosin-stained slide from 25 randomly selected grade 3 endometrioid carcinomas and 25 high-grade serous carcinomas. Histotype was independently assigned by 5 pathologists initially blinded to immunohistochemical WT1/p53 status, with subsequent reassessment unblinded to WT1/p53 status. Patients diagnosed with grade 3 endometrioid carcinoma had a significantly longer survival compared with high-grade serous carcinoma in univariate analysis (hazard ratio [HR]=0.34, 95% confidence interval [CI]=0.16-0.67, P=0.0012) but not after adjusting for age, stage, treatment center, and residual tumor (HR=1.01, 95% CI=0.43-2.16, P=0.98). Grade 3 endometrioid carcinoma cases (N=30) were identical to grade 2 endometrioid carcinoma cases (N=23) with respect to survival in univariate analysis (HR=1.07, 95% CI=0.39-3.21, P=0.89) and immunohistochemical profile. Using histomorphology alone, interobserver agreement for the diagnosis of grade 3 endometrioid or high-grade serous carcinoma was 69%, which significantly increased (P<0.0001) to 96% agreement with the knowledge of WT1/p53 status. Our data support the diagnostic value of WT1/p53 status in differentiating between grade 3 endometrioid carcinoma and high-grade serous carcinoma. However, grade 3 and grade 2 endometrioid carcinomas showed no differences in immunophenotype or clinical parameters, suggesting that they could be combined into a single group.

A case of ovarian endometrioid adenocarcinoma with yolk sac differentiation and Lynch syndrome

Ovarian endometrioid adenocarcinoma with yolk sac component has been reported in fewer than twenty cases in the literature. A majority of the diagnoses are described in postmenopausal women without specific reference to germline genetic testing. We describe, to our knowledge, the first case in the English literature of a premenopausal woman that presented with an ovarian endometrioid adenocarcinoma with focal yolk sac component and was subsequently found to have a germline MSH2 mutation confirming a diagnosis of Lynch syndrome. Concurrent diagnosis of ovarian endometrioid adenocarcinoma with yolk sac tumor and Lynch syndrome is an extremely rare finding in a young patient and requires careful follow-up. Genetics evaluation and testing may be reasonable for individuals with this rare or mixed tumor pathology at young age of onset and can have clinical utility in guiding future cancer treatment or surveillance.

The Epigenetic Landscape in the Treatment of Gynecologic Malignancies

The care of patients with advanced-stage or recurrent endometrial, ovarian, and cervical cancer remains clinically challenging. Despite the identification of novel therapeutics and advancements in supportive care, survival outcomes have been relatively unchanged over the past decade. In addition to established genomic alterations and the contributions of the tumor microenvironment to cancer progression, epigenetic mechanisms have emerged as important contributors to gynecologic cancer progression. DNA methylation, histone modification, and noncoding RNA expression may be important contributors to disease initiation and progression and may represent novel therapeutic targets. This article reviews the epigenetic landscape of endometrial, ovarian, and cervical cancer, describing the state of the science and discussing potential clinical applications. To date, the role of epigenetic drugs in the treatment of gynecologic cancers remains unclear, although continued progress may inform future treatment modalities.

Mismatch repair deficiency is associated with MSI phenotype, increased tumor-infiltrating lymphocytes and PD-L1 expression in immune cells in ovarian cancer

OBJECTIVE

The role of mismatch repair (MMR) deficiency in ovarian cancer (OC) pathogenesis and its association with other clinicopathologic features, such as microsatellite instability (MSI) and expression of checkpoint proteins, remain largely elusive.

METHODS

We performed Immunohistochemistry (IHC) for MLH1, MSH2, MSH6 and PMS2 on full-section slides from 419 OCs to assess the MMR status. The clinical relevance of MMR deficiency was analyzed in combination with clinical data. The MSI status (by MSI assay) and expression of CD3, CD8, PD-1 and PD-L1 (by IHC) were compared in OCs with different MMR status.

RESULTS

We found that 2.6% OCs were MMR-negative, 4.3% OCs were MMR-low, and 63.6% of MMR-negative OCs were of endometrioid subtype. A significantly higher proportion of MMR-negative OCs were diagnosed at stage I or II compared to MMR-proficient OCs (p=0.0041). MSI was observed in all tested MMR-negative OCs, 14.3% of tested MMR-low OCs and 3.2% of tested MMR-proficient OCs. In addition, MMR-negative OCs had better progression free survival compared to MMR-proficient and MMR-low OCs (p=0.0046). Furthermore, the majority of OCs were PD-1-positive in intratumoral lymphocytes regardless of MMR status; while MMR-negative OCs exhibited significantly increased CD3+ and CD8+ tumor-infiltrating lymphocytes, and PD-L1+ intratumoral immune cells compared to MMR-proficient OCs.

CONCLUSION

Our data suggests that MMR deficient OC is a unique molecular subgroup, characterized by early stage of diagnosis, MSI phenotype, and increased tumor-infiltrating lymphocytes. These patients may be good candidates for anti-PD-1/PD-L1 therapy.

Screening for Lynch syndrome using risk assessment criteria in patients with ovarian cancer

Objective

Lynch syndrome is a cancer predisposition syndrome caused by germline mutation of DNA mismatch repair (MMR) genes. Lynch syndrome only causes about 0.4% of cases of ovarian cancer, which suggests that universal screening may not be cost-efficient. However, the frequency of Lynch syndrome in ovarian cancer is unclear in the Asian population. The goal of the study was to investigate a screening strategy using family history.

Methods

The subjects were 129 patients with ovarian cancer. Clinical and family history were collected using a self-administered questionnaire, and Society of Gynecologic Oncology (SGO) criteria 2007 and PREMM₅ were used for risk assessment. Microsatellite instability, immunohistochemistry, and methylation of MMR genes were analyzed.

Results

Of the 129 cases, 25 (19.4%) met the SGO criteria, and 4 of these 25 had MSI-high and MMR deficiency. Two cases had loss of MSH2 and MSH6, indicating MSH2 mutation, and the other two had loss of MLH1 and PMS2, including one without MLH1 methylation indicating MLH1 mutation. These results show that screening using family history can detect Lynch syndrome in 12.0% (3/25) of ovarian cancer cases. The 3 cases were positive for PREMM₅, but negative for Amsterdam II criteria and revised Bethesda guidelines. Genetic testing in one case with MSH2 and MSH6 deficiency confirmed the diagnosis of Lynch syndrome with MSH2 mutation.

Conclusion

This is the first study of screening for Lynch syndrome in ovarian cancer using clinical and family history in an Asian population. This approach may be effective for diagnosis in these patients.

Comprehensive Clinicopathologic and Updated Immunohistochemical Characterization of Primary Ovarian Mucinous Carcinoma

The distinction of primary mucinous ovarian carcinoma (PMOC) from other primaries or secondaries is essential for selecting therapeutic options and prognostication. We aimed to characterize the immunohistochemical profile of 36 PMOCs using an extended immunohistochemical panel, with clinicopathologic features and outcome. PAX8 was negative in 30 (83.3%), and SATB2 was negative in 32/35. HNF1B, AMACR, and napsin-A were detected in 33 (91.7%), 35 (97.2%), and 0 (0%), respectively. MMR proteins and ARID1A were retained in 100%; PTEN was lost in 4 (11.1%). P53 was aberrant in 10 (27.8%); none overexpressed p16. HER2 was positive in 6/35 (17.1%). Most PMOCs had a favorable outcome. However, recurrence is usually fatal. The typical tumor profile was CK7+, CK20+/-, CDX2+/-, PAX8-, ER-, PgR-, and SATB2-. HER2 positivity suggests a possible target for therapy in advanced disease.

Gynaecological neoplasms in common familial syndromes (Lynch and HBOC)

Recognising hereditary predisposition in a cancer patient has implications both for the patient and the patient's kindred. For the latter, cascade germline testing can reassure those not-at-risk family members while carriers can be enrolled in cancer screening and prevention programs that are medically effective and economically sustainable for health care systems. Furthermore, in many of these syndromes, ramifications of molecular phenotypes are increasing, and it is now emerging that, in addition, they convey prognostic and predictive information. Although cancer predisposition syndromes are rare, these molecular phenotypes also occur as somatic events in sporadic cancer settings. The information obtained from these molecular phenotypes, regardless of germline or somatic origin, is being incorporated into clinical management in view of their manifold significance. Thus, increasingly, bespoke management of cancer patients involves testing for both germline and somatic mutations in tumours. Lynch syndrome and BRCA-1 and BRCA-2-associated hereditary breast and ovarian cancer are hereditary cancer syndromes frequently involving the gynaecological tract but tumours associated with similar molecular alterations may also occur sporadically. Thus, the molecular phenotype of mismatch repair deficiency, microsatellite instability or hypermutator phenotype may be attributable to germline or somatic events. Similarly, homologous recombination deficiency or 'BRCAness' in ovarian cancers may be syndromic or sporadic. While hereditary syndromes are well recognised, the prognostic and predictive implications of these molecular phenotypes have only recently been elucidated and these aspects will finally ensure that molecular screening may become standard of care. Thus, nowadays pathologists are asked to designate the molecular phenotype of these cancers and then determine whether it is due to hereditary or sporadic causes.

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 trend = 4.2 × 10−16). 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.

Molecular-based classification algorithm for endometrial carcinoma categorizes ovarian endometrioid carcinoma into prognostically significant groups

The Cancer Genome Atlas classification divides endometrial carcinoma in biologically distinct groups, and testing for p53, mismatch repair proteins (MMR), and polymerase ɛ (POLE) exonuclease domain mutations has been shown to predict the molecular subgroup and clinical outcome. While abnormalities in these markers have been described in ovarian endometrioid carcinoma, their role in predicting its molecular profile and prognosis is still not fully explored. Patients with ovarian endometrioid carcinomas treated surgically in a 14-year period were selected. Only tumors with confirmation of endometrioid histology and negative WT1 and Napsin-A were included. POLE mutational analysis and immunohistochemistry for p53, MLH1, MSH2, MSH6, and PMS2 was performed in formalin-fixed, paraffin-embedded tissue. Following the molecular classifier proposed for endometrial carcinoma (Br J Cancer2015;113:299-310), cases were classified as POLE mutated, MMR abnormal, p53 abnormal, and p53 wild type. Clinicopathologic information was recorded, including patient outcome. In all, 72 cases were included, distributed as follows: 7 (10%) POLE mutated; 6 (8%) MMR abnormal; 17 (24%) p53 abnormal; and 42 (58%) p53 wild type. The molecular classification correlated with disease-free survival in multivariate analysis (P=0.003), independently of tumor grade and stage. Correlation with overall survival approached statistical significance (P=0.051). POLE-mutated and MMR-abnormal tumors had excellent survival, whereas p53-abnormal tumors had significantly higher rates of recurrence and death. Ovarian endometroid carcinoma can be classified in clinically meaningful subgroups by testing for molecular surrogates, akin to endometrial cancer. MMR and POLE alterations seem to identify a subset of ovarian endometrioid carcinomas with excellent outcome; conversely, abnormal p53 carries a worse prognosis. In the era of personalized medicine, the use of these markers in the routine evaluation of ovarian endometrioid tumors should be considered.

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 trend = 4.2 × 10−16). 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.

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 trend = 4.2 × 10−16). 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.

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.

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

PURPOSE

Synchronous 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.

METHODS

We included patients with endometrioid (n = 180) and clear cell (n = 165) 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.

RESULTS

Comparing 52 patients with SEO tumors to 293 patients with endometrioid or clear cell ovarian carcinomas, endometriosis at the ovary (OR = 0.45, 95% CI = 0.23-0.87, p = 0.02) was the strongest predictor of decreased risk in multivariable models. Premenopausal status (OR = 2.17, 95% CI = 0.92-5.13, p = 0.08) and lower pre-treatment CA125 levels (OR = 0.17, 95% CI = 0.02-1.32, p = 0.09) 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 (p ≤ 0.03).

CONCLUSIONS

Endometriosis 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.

Long-term survival of patients with mismatch repair protein-deficient, high-stage ovarian clear cell carcinoma

AIMS

Gynaecological cancer patients with germline mutations appear to have a better prognosis than those with sporadic malignancies. Following the observation of long-term survival in a patient with stage III ovarian clear cell carcinoma (CCC) and possible Lynch syndrome (LS), DNA mismatch repair (MMR) protein immunohistochemistry was performed in a series of high-stage CCC and correlated with patient outcomes.

METHODS AND RESULTS

Thirty-two consecutive cases of stage III/IV ovarian CCCs accessioned between 1992 and 2015 were examined. The tumours from two patients (6%), including the index case, showed loss of MSH2/MSH6 expression while MLH1/PMS2 staining was retained. The index patient subsequently developed colonic and rectal carcinomas that were also MSH2/MSH6-deficient, while the second patient had a genetically confirmed germline MSH2 mutation. All other tumours showed retained expression of the four MMR proteins. The two patients with MMR protein-deficient tumours were alive 160 months and 124 months following surgery, whereas the median survival of patients with MMR protein-intact CCCs was 11.8 months (75th and 25th percentiles of 8.1 months and 39.3 months, respectively), with 21 patients deceased due to tumour.

CONCLUSIONS

Larger studies are required but high-stage, MMR protein-deficient CCCs may have a relatively favourable prognosis.