Ovarian cancer epidemiology in the era of collaborative team science

The association of body composition phenotypes before chemotherapy with epithelial ovarian cancer mortality

BACKGROUND

The association of body composition with epithelial ovarian carcinoma (EOC) mortality is poorly understood. To date, evidence suggests high adiposity associates with decreased mortality (an obesity paradox), but the impact of muscle on this association has not been investigated. Herein, we define associations of muscle and adiposity joint-exposure body composition phenotypes with EOC mortality.

METHODS

Body composition from 500 women in The Body Composition and Epithelial Ovarian Cancer Survival Study was dichotomized as normal/low skeletal muscle index (SMI), a proxy for sarcopenia and high/low adiposity. Four phenotypes were classified as fit/reference (normal SMI/low adiposity; 16.2%), overweight/obese (normal SMI/high adiposity; 51.2%), sarcopenia/overweight-obese (low SMI/high adiposity; 15.6%), and sarcopenia/cachexia (low SMI/low adiposity; 17%). We used multivariable Cox models to estimate associations of each phenotype with mortality for EOC overall and high-grade serous ovarian carcinoma (HGSOC).

RESULTS

Overweight/obesity was associated with up to 51% and 104% increased mortality in EOC and HGSOC (HR = 1.51, 95% CI: 1.05-2.19 and HR = 2.04, 95% CI: 1.29-3.21). Sarcopenia/overweight-obesity was associated with up to 66% and 67% increased mortality in EOC and HGSOC (HR = 1.66, 95% CI: 1.13-2.45 and HR = 1.67, 95% CI: 1.05-2.68). Sarcopenia/cachexia was associated with up to 73% and 109% increased mortality in EOC and HGSOC (HR = 1.73, 95% CI: 1.14-2.63 and HR = 2.09, 95% CI: 1.25-3.50).

CONCLUSIONS

Overweight/obesity, sarcopenia/overweight-obesity and sarcopenia/cachexia phenotypes were each associated with increased mortality in EOC and HGSOC. Exercise and dietary interventions could be leveraged as ancillary treatment strategies for improving outcomes in the most fatal gynecological malignancy with no previously established modifiable prognostic factors.

High Prediagnosis Inflammation-Related Risk Score Associated with Decreased Ovarian Cancer Survival

BACKGROUND

There is suggestive evidence that inflammation is related to ovarian cancer survival. However, more research is needed to identify inflammation-related factors that are associated with ovarian cancer survival and to determine their combined effects.

METHODS

This analysis used pooled data on 8,147 women with invasive epithelial ovarian cancer from the Ovarian Cancer Association Consortium. The prediagnosis inflammation-related exposures of interest included alcohol use; aspirin use; other nonsteroidal anti-inflammatory drug use; body mass index; environmental tobacco smoke exposure; history of pelvic inflammatory disease, polycystic ovarian syndrome, and endometriosis; menopausal hormone therapy use; physical inactivity; smoking status; and talc use. Using Cox proportional hazards models, the relationship between each exposure and survival was assessed in 50% of the data. A weighted inflammation-related risk score (IRRS) was developed, and its association with survival was assessed using Cox proportional hazards models in the remaining 50% of the data.

RESULTS

There was a statistically significant trend of increasing risk of death per quartile of the IRRS [HR = 1.09; 95% confidence interval (CI), 1.03-1.14]. Women in the upper quartile of the IRRS had a 31% higher death rate compared with the lowest quartile (95% CI, 1.11-1.54).

CONCLUSIONS

A higher prediagnosis IRRS was associated with an increased mortality risk after an ovarian cancer diagnosis. Further investigation is warranted to evaluate whether postdiagnosis exposures are also associated with survival.

IMPACT

Given that pre- and postdiagnosis exposures are often correlated and many are modifiable, our study results can ultimately motivate the development of behavioral recommendations to enhance survival among patients with ovarian cancer.

Endometriosis and menopausal hormone therapy impact the hysterectomy-ovarian cancer association

OBJECTIVE

To evaluate the association between hysterectomy and ovarian cancer, and to understand how hormone therapy (HT) use and endometriosis affect this association.

METHODS

We conducted a pooled analysis of self-reported data from 11 case-control studies in the Ovarian Cancer Association Consortium (OCAC). Women with (n = 5350) and without ovarian cancer (n = 7544) who never used HT or exclusively used either estrogen-only therapy (ET) or estrogen+progestin therapy (EPT) were included. Risk of invasive epithelial ovarian cancer adjusted for duration of ET and EPT use and stratified on history of endometriosis was determined using odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Overall and among women without endometriosis, there was a positive association between ovarian cancer risk and hysterectomy (OR = 1.19, 95% CI 1.09-1.31 and OR = 1.20, 95% CI 1.09-1.32, respectively), but no association upon adjusting for duration of ET and EPT use (OR = 1.04, 95% CI 0.94-1.16 and OR = 1.06, 95% CI 0.95-1.18, respectively). Among women with a history of endometriosis, there was a slight inverse association between hysterectomy and ovarian cancer risk (OR = 0.93, 95% CI 0.69-1.26), but this association became stronger and statistically significant after adjusting for duration of ET and EPT use (OR = 0.69, 95% CI 0.48-0.99).

CONCLUSIONS

The hysterectomy-ovarian cancer association is complex and cannot be understood without considering duration of ET and EPT use and history of endometriosis. Failure to take these exposures into account in prior studies casts doubt on their conclusions. Overall, hysterectomy is not risk-reducing for ovarian cancer, however the inverse association among women with endometriosis warrants further investigation.

Joint IARC/NCI International Cancer Seminar Series Report: expert consensus on future directions for ovarian carcinoma research

Recently, ovarian cancer research has evolved considerably because of the emerging recognition that rather than a single disease, ovarian carcinomas comprise several different histotypes that vary by etiologic origin, risk factors, molecular profiles, therapeutic approaches and clinical outcome. Despite significant progress in our understanding of the etiologic heterogeneity of ovarian cancer, as well as important clinical advances, it remains the eighth most frequently diagnosed cancer in women worldwide and the most fatal gynecologic cancer. The International Agency for Research on Cancer and the United States National Cancer Institute jointly convened an expert panel on ovarian carcinoma to develop consensus research priorities based on evolving scientific discoveries. Expertise ranged from etiology, prevention, early detection, pathology, model systems, molecular characterization and treatment/clinical management. This report summarizes the current state of knowledge and highlights expert consensus on future directions to continue advancing etiologic, epidemiologic and prognostic research on ovarian carcinoma.

Depot-Medroxyprogesterone Acetate Use Is Associated with Decreased Risk of Ovarian Cancer: The Mounting Evidence of a Protective Role of Progestins

BACKGROUND

Combined oral contraceptive use is associated with a decreased risk of invasive epithelial ovarian cancer (ovarian cancer). There is suggestive evidence of an inverse association between progestin-only contraceptive use and ovarian cancer risk, but previous studies have been underpowered.

METHODS

The current study used primary data from 7,977 women with ovarian cancer and 11,820 control women in seven case-control studies from the Ovarian Cancer Association Consortium to evaluate the association between use of depot-medroxyprogesterone acetate (DMPA), an injectable progestin-only contraceptive, and ovarian cancer risk. Logistic models were fit to determine the association between ever use of DMPA and ovarian cancer risk overall and by histotype. A systematic review of the association between DMPA use and ovarian cancer risk was conducted.

RESULTS

Ever use of DMPA was associated with a 35% decreased risk of ovarian cancer overall (OR, 0.65; 95% confidence interval, 0.50-0.85). There was a statistically significant trend of decreasing risk with increasing duration of use (P trend < 0.001). The systematic review yielded six studies, four of which showed an inverse association and two showed increased risk.

CONCLUSIONS

DMPA use appears to be associated with a decreased risk of ovarian cancer in a duration-dependent manner based on the preponderance of evidence. Further study of the mechanism through which DMPA use is associated with ovarian cancer is warranted.

IMPACT

The results of this study are of particular interest given the rise in popularity of progestin-releasing intrauterine devices that have a substantially lower progestin dose than that in DMPA, but may have a stronger local effect.

miR-22 suppresses cell viability and EMT of ovarian cancer cells via NLRP3 and inhibits PI3K/AKT signaling pathway

PURPOSE

miR-22 plays a great role in inhibiting cell growth, metastasis and enhanced cell apoptosis in several cancers. The purpose of this study was to investigate the functions of miR-22 in ovarian cancer.

METHODS

The proliferative ability was measured using CCK-8 assay. The protein expression associated with EMT and PI3K/AKT signaling biomarkers were measured by western blot. Luciferase assay applied to measure the luciferase activity. Kaplan-Meier method was performed to evaluate the overall survival rate of ovarian cancers.

RESULTS

miR-22 was low expressed and NLRP3 was overexpressed in ovarian cancer tissues and cells, and downregulation of miR-22 was associated with poor prognosis. The expression of NLRP3 had a negative correlation with miR-22 expression in ovarian cancer. miR-22 promoted cell viability and EMT through directly binding to the 3'-UTR of NLRP3 mRNA and inhibited PI3K/AKT signaling pathway. NLRP3 partially restored functions of miR-22 on cell proliferation and EMT in ovarian cancer.

CONCLUSION

miR-22 impaired cell viability and EMT by NLRP3 and inhibited PI3K/AKT signaling pathway in ovarian cancer. The newly identified miR-22/NLRP3/PI3K/AKT axis provides novel insight into the pathogenesis of ovarian cancer.

Racial/ethnic disparities in ovarian cancer research

Ovarian cancer is one of the most fatal cancers diagnosed in women in the United States (U.S.). Data from national databases, including the Surveillance Epidemiology and End Results (SEER) program, show racial/ethnic differences in risk and survival of epithelial ovarian cancer with higher incidence among white women yet worse survival among African-American women compared to other racial/ethnic groups. The reasons for these differences are not well understood, but are likely multi-factorial. Epidemiologic studies suggest there may be some risk factor differences across racial/ethnic groups that would explain differences in the incidence of this rare and heterogeneous disease. Likewise, although data suggest that socioeconomic factors and access to care contribute to the disparity in ovarian cancer survival among African-American women, there are likely other contributing factors that have not as of yet been identified. Small sample sizes of minority women from individual studies do not provide adequate power to evaluate fully the contributions of environmental, genetic, and clinical factors associated with ovarian cancer risk and survival within these groups. Pooling existing data from individual epidemiologic studies has made a valuable contribution; however, new data collection is warranted to further our understanding of the underpinnings of the disparities in ovarian cancer that may lead to prevention and improved survival across all racial/ethnic groups.

Dynamic change of depression and anxiety after chemotherapy among patients with ovarian cancer

Psychological state of patients with ovarian cancer is worthy of attention. We aimed to investigate the levels of anxiety and depression in patients with ovarian cancer. We also investigated the dynamic changes in anxiety and depression levels after chemotherapy.A total of 228 females were included in this study. Among them, a total of 111 participants had ovarian cancer and 117 females who underwent a physical examination were selected as healthy controls. All patients enrolled were asked to fill in the Self-rating Depression Scale and the Self-rating Anxiety Scale. For patients with ovarian cancer, repeat questionnaires were measured after cycle 1 chemotherapy.The depression score of patients with ovarian cancer was 45.90 ± 10.19, significantly higher than in controls (36.08 ± 9.06, P < .001). Similar results were observed in respect of anxiety score. The score of ovarian cancer patients was 39.53 ± 12.92, significantly higher than of controls (32.15 ± 7.44, P < .001). Multivariate analyses were conducted, and the results showed that young age was the independent risk factor associated with depression among patients with ovarian cancer, while young age and singleness were the independent risk factors associated with anxiety. Repeat questionnaires were measured after chemotherapy. Interestingly, we found depression scores decreased from 45.90 ± 10.19 to 36.29 ± 8.98 after chemotherapy (P < .001), while anxiety score increased from 39.53 ± 12.92 to 42.75 ± 9.96 after chemotherapy (P = .009). Multivariate analysis suggested that only higher income and higher baseline depression score were the independent and most relevant risk factors associated with depression remission after chemotherapy. For patients with anxiety remission, only higher baseline anxiety score was the independent risk factor associated with anxiety remission.This study suggests that for patients with ovarian cancer, timely monitoring of the patient's psychological state, especially before and after chemotherapy treatment, is very important. Assessing the changes in the patient's psychological state, screening the population with risk factors, and prompt intervention by mobilizing social support may be effective in preventing depression and anxiety in such population.

Association between Cigarette Smoking and Histotype-Specific Epithelial Ovarian Cancer: A Review of Epidemiologic Studies

Many studies have demonstrated that smoking can influence ovarian cancer risk and survival; however, the number of studies investigating this relationship according to histologic subtypes is limited. We conducted a review of epidemiologic research that assessed the role of smoking on ovarian cancer risk and survival after diagnosis, specifically capturing studies that discerned between various histologic subtypes of this disease. In the majority of studies, current smoking was associated with increased risk of mucinous cancer. There was also evidence of a decreased risk of clear cell and endometrioid histotypes. No significant association was observed between cigarette smoking and serous cancer. In the studies investigating the relationship between smoking and survival, all the studies reported an increased risk of mortality associated with smoking. Smoking appeared to be a risk factor for both ovarian cancer risk and mortality. Future studies need to investigate further a potential link between smoking and ovarian cancer by having a better assessment of exposure to smoking and having a larger number of participants with the ability to detect associations within rare histotypes.

Upregulation of long non-coding RNA XIST has anticancer effects on epithelial ovarian cancer cells through inverse downregulation of hsa-miR-214-3p

OBJECTIVE

The present study is to evaluate the biological functions of long non-coding RNA (lncRNA), X-inactive specific transcript, X-inactive specific transcript (XIST) in human epithelial ovarian cancer (EOC).

METHODS

XIST was upregulated in EOC cell lines, CAOV3 and OVCAR3 cells by lentiviral transduction. The effects of XIST overexpression on cancer cell proliferation, invasion, chemosensitivity and in vivo tumor growth were investigated, respectively. Possible sponging interaction between XIST and human microRNA hsa-miR-214-3p was further evaluated. Furthermore, hsa-miR-214-3p was overexpressed in XIST-upregulated CAOV3 and OVCAR3 cells to evaluate its effect on XIST-mediated EOC regulation.

RESULTS

Lentivirus-mediated XIST upregulation had significant anticancer effects in CAOV3 and OVCAR3 cells by suppressing cancer cell proliferation, invasion, increasing cisplatin chemosensitivity and inhibiting in vivo tumor growth. Hsa-miR-214-3p was confirmed to directly bind XIST, and inversely downregulated in XIST-upregulated EOC cells. In EOC cells with XIST upregulation, secondary lentiviral transduction successfully upregulated hsa-miR-214-3p expression. Subsequently, hsa-miR-214-3p upregulation functionally reversed the anticancer effects of XIST-upregulation in EOC.

CONCLUSION

Upregulation of lncRNA XIST may suppress EOC development, possibly through sponging effect to induce hsa-miR-214-3p downregulation.

Invasive Epithelial Ovarian Cancer Survival by Histotype and Disease Stage

Background

The understanding of ovarian cancer pathogenesis has recently shifted to recognize distinct changes in how ovarian cancer histotypes are defined. Using the 2014 World Health Organization (WHO) diagnostic guidelines, we classified ovarian cancer histotypes in Surveillance, Epidemiology, and End Results (SEER) cancer registry data and examined survival patterns by histotype and disease stage.

Methods

We extracted data on 28 118 incident epithelial ovarian cancer cases diagnosed in 2004-2014 from SEER and defined histotype using the 2014 WHO guidelines (high-grade serous, low-grade serous, endometrioid, clear cell, mucinous, carcinosarcoma, and malignant Brenner tumors). By histotype and disease stage, we estimated Kaplan-Meier survival curves and calculated age-adjusted overall and cause-specific survival estimates. Cox proportional hazards regression models were used to estimate histotype-specific hazard ratios (HRs) and 95% confidence intervals (CIs) by disease stage while adjusting for age at diagnosis, region, race/ethnicity, and receipt of surgery.

Results

Within two years after diagnosis, localized/regional-stage carcinosarcoma and distant-stage mucinous, clear cell, and carcinosarcoma had a higher risk of mortality compared with high-grade serous, with the most pronounced association for localized/regional carcinosarcoma (>1-2-year time period: HR = 3.81, 95% CI = 2.74 to 5.30) and distant-stage mucinous (0-1-year time period: HR = 3.87, 95% CI = 3.45 to 4.34). In the time period more than four to 10 years after diagnosis, hazard ratios for all histotypes relative to high-grade serous, irrespective of disease stage, were less than 1.00. Cumulatively, both localized/regional and distant-stage low-grade serous and endometrioid carcinomas had the most favorable outcomes.

Conclusions

Our large study, which is representative of the United States population and incorporates the most current knowledge of ovarian cancer pathogenesis, highlights the need to recognize ovarian cancer as a set of distinct diseases and not a single entity. Only then will we be able to effectively target the unique features of each histotype to reduce ovarian cancer mortality.

Long noncoding RNA CASC9 promotes LIN7A expression via miR-758-3p to facilitate the malignancy of ovarian cancer

The long noncoding RNA cancer susceptibility 9 (CASC9) has been reported to be a pivot modulator in growth and metastasis of breast cancer, liver cancer, esophageal squamous cell carcinoma, lung adenocarcinoma, gastric cancer, and nasopharyngeal cancer. However, its potential roles in ovarian cancer remain unclear. In this study, we aimed at its functions and molecular mechanism in ovarian cancer progression. We showed that CASC9 was highly expressed in ovarian cancer tissues and cell lines. An elevated level of CASC9 predicts an unfavorable prognosis in patients with ovarian cancer. Loss-of-function and gain-of-function assays illustrated that CASC9 promotes ovarian cancer cell proliferation, migration, and invasion in vitro, and accelerates tumor growth in vivo. We showed that CASC9 works as a competing endogenous RNA (ceRNA) for miR-758-3p which targets LIN7A. CASC9 inhibits the level of miR-758-3p, and in turn stimulates LIN7A expression in ovarian cancer. Overexpression of LIN7A reverses the suppressive roles of CASC9 depletion on ovarian cancer. In sum, our findings reveal a novel undefined regulatory signaling pathway, namely CASC9/miR-758-3p/LIN7A axis, involved in ovarian cancer progression.

Histotype classification of ovarian carcinoma: A comparison of approaches

OBJECTIVE

Major changes in the classification of ovarian carcinoma histotypes occurred over the last two decades, resulting in the current 2014 World Health Organization (WHO) diagnostic criteria that recognize five principal histotypes: high-grade serous, low-grade serous, endometrioid, clear cell, and mucinous carcinoma. We assessed the impact of these guidelines and use of immunohistochemical (IHC) markers on classification of ovarian carcinomas in existing population-based studies.

METHODS

We evaluated histotype classification for 2361 ovarian carcinomas diagnosed between 1999 and 2009 from two case-control studies using three approaches: 1. pre-2014 WHO ("historic") histotype; 2. Standardized review of pathology slides using the 2014 WHO criteria alone; and 3. An integrated IHC assessment along with the 2014 WHO criteria. We used Kappa statistics to assess agreement between approaches, and Kaplan-Meier survival curves and Cox proportional hazards models to evaluate mortality.

RESULTS

Compared to the standardized pathologic review histotype, agreement across approaches was high (kappa = 0.892 for historic, and 0.849 for IHC integrated histotype), but the IHC integrated histotype identified more low-grade serous carcinomas and a subset of endometrioid carcinomas that were assigned as high-grade serous (n = 25). No substantial differences in histotype-specific mortality were observed across approaches.

CONCLUSIONS

Our findings suggest that histotype assignment is fairly consistent regardless of classification approach, but that progressive improvements in classification accuracy for some less common histotypes are achieved with pathologic review using the 2014 WHO criteria and with IHC integration. We additionally recommend a classification scheme to fit historic data into the 2014 WHO categories to answer histotype-specific research questions.

Challenges and Opportunities in Studying the Epidemiology of Ovarian Cancer Subtypes

PURPOSE OF REVIEW

Only recently has it become clear that epithelial ovarian cancer (EOC) is comprised of such distinct histotypes--with different cells of origin, morphology, molecular features, epidemiologic factors, clinical features, and survival patterns-that they can be thought of as different diseases sharing an anatomical location. Herein, we review opportunities and challenges in studying EOC heterogeneity.

RECENT FINDINGS

The 2014 World Health Organization diagnostic guidelines incorporate accumulated evidence that high- and low-grade serous tumors have different underlying pathogenesis, and that, on the basis of shared molecular features, most high grade tumors, including some previously classified as endometrioid, are now considered to be high-grade serous. At the same time, several studies have reported that high-grade serous EOC, which is the most common histotype, is itself made up of reproducible subtypes discernable by gene expression patterns.

SUMMARY

These major advances in understanding set the stage for a new era of research on EOC risk and clinical outcomes with the potential to reduce morbidity and mortality. We highlight the need for multidisciplinary studies with pathology review using the current guidelines, further molecular characterization of the histotypes and subtypes, inclusion of women of diverse racial/ethnic and socioeconomic backgrounds, and updated epidemiologic and clinical data relevant to current generations of women at risk of EOC.

Challenges and Opportunities in Studying the Epidemiology of Ovarian Cancer Subtypes

Purpose of review

Only recently has it become clear that epithelial ovarian cancer (EOC) is comprised of such distinct histotypes--with different cells of origin, morphology, molecular features, epidemiologic factors, clinical features, and survival patterns-that they can be thought of as different diseases sharing an anatomical location. Herein, we review opportunities and challenges in studying EOC heterogeneity.

Recent findings

The 2014 World Health Organization diagnostic guidelines incorporate accumulated evidence that high- and low-grade serous tumors have different underlying pathogenesis, and that, on the basis of shared molecular features, most high grade tumors, including some previously classified as endometrioid, are now considered to be high-grade serous. At the same time, several studies have reported that high-grade serous EOC, which is the most common histotype, is itself made up of reproducible subtypes discernable by gene expression patterns.

Summary

These major advances in understanding set the stage for a new era of research on EOC risk and clinical outcomes with the potential to reduce morbidity and mortality. We highlight the need for multidisciplinary studies with pathology review using the current guidelines, further molecular characterization of the histotypes and subtypes, inclusion of women of diverse racial/ethnic and socioeconomic backgrounds, and updated epidemiologic and clinical data relevant to current generations of women at risk of EOC.

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.

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.

Challenges and Opportunities in Studying the Epidemiology of Ovarian Cancer Subtypes

PURPOSE OF REVIEW

Only recently has it become clear that epithelial ovarian cancer (EOC) is comprised of such distinct histotypes--with different cells of origin, morphology, molecular features, epidemiologic factors, clinical features, and survival patterns-that they can be thought of as different diseases sharing an anatomical location. Herein, we review opportunities and challenges in studying EOC heterogeneity.

RECENT FINDINGS

The 2014 World Health Organization diagnostic guidelines incorporate accumulated evidence that high- and low-grade serous tumors have different underlying pathogenesis, and that, on the basis of shared molecular features, most high grade tumors, including some previously classified as endometrioid, are now considered to be high-grade serous. At the same time, several studies have reported that high-grade serous EOC, which is the most common histotype, is itself made up of reproducible subtypes discernable by gene expression patterns.

SUMMARY

These major advances in understanding set the stage for a new era of research on EOC risk and clinical outcomes with the potential to reduce morbidity and mortality. We highlight the need for multidisciplinary studies with pathology review using the current guidelines, further molecular characterization of the histotypes and subtypes, inclusion of women of diverse racial/ethnic and socioeconomic backgrounds, and updated epidemiologic and clinical data relevant to current generations of women at risk of EOC.