Hormonal and reproductive risk factors for epithelial ovarian cancer by tumor aggressiveness

Contraceptive strategies for reducing the risk of reproductive cancers

Reproductive cancers, encompassing various malignancies like endometrial, ovarian, cervical cancer, and gestational trophoblastic neoplasia, pose a significant global health burden. Understanding their patterns is vital for effective prevention and management. Contraceptives show a protective effect against some of these cancers. This clinical guidance document aims to elucidate the disease burden of reproductive cancers and the evidence supporting contraceptive methods in prevention and management. Regional disparities in incidence and mortality highlight the urgent need for targeted interventions, particularly in low-resource settings. Healthcare providers must weigh individual risk profiles and medical eligibility criteria when discussing contraceptive options. Enhanced health literacy through direct patient education is essential for leveraging low-cost behavioral interventions to mitigate reproductive cancer risks.

Association of levonorgestrel-releasing intrauterine device with gynecologic and breast cancers: a national cohort study in Sweden

BACKGROUND

The levonorgestrel-releasing intrauterine device (LNG-IUD) is widely used for the treatment of menorrhagia, dysmenorrhea, and for contraception. However, the association between the use of LNG-IUD and the risk of site-specific gynecologic and breast cancers remains inconclusive.

OBJECTIVE

We aim to address this knowledge gap by investigating whether the use of LNG-IUD is associated with a significant risk of site-specific gynecologic and breast cancers. This will be achieved by accessing the nationwide Swedish Registers, with consideration given to the influence and potential interaction of family history of cancer.

STUDY DESIGN

A total of 514,719 women aged 18 to 50 years who have used LNG-IUD between July 2005 and December 2018 were identified from the Swedish Prescribed Drug Register and randomly matched with 1,544,157 comparisons who did not use LNG-IUD at a ratio of 1:3. The propensity score was calculated and matched among women who used LNG-IUD and the matched comparisons. The follow-up period started from the date of the first prescription of LNG-IUD for users as well as for their matched comparisons and ended at the date of diagnosis of gynecologic and breast cancers, date of death from any cause, and the end of the study period, whichever came first. The Cox proportional hazard model with a competing risk analysis was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Additive interaction was calculated as the relative excess risk for interaction, while multiplicative interaction was calculated by including a product term in the regression model.

RESULTS

The use of LNG-IUD was associated with a 13% higher risk of breast cancer (adjusted HR, 1.13; 95% CI, 1.10-1.17), a 33% lower risk of endometrial cancer (adjusted HR, 0.67; 95% CI, 0.56-0.80), a 14% lower risk of ovarian cancer (adjusted HR, 0.86; 95% CI, 0.75-0.99), and a 9% reduced risk of cervical cancer (adjusted HR, 0.91; 95% CI, 0.84-0.99) compared to women who did not use LNG-IUD. A significant additive interaction between LNG-IUD use and family history of cancer was observed in breast cancer, indicating a relative 19% excess risk for interaction (P<.002), and 1.63 additional cases per 10,000 person-years.

CONCLUSION

The risk of gynecologic and breast cancers exhibits a site-specific effect among LNG-IUD users. It is important to note that the observed effect is small for breast cancer and the results are limited by the observational study design. Clinical recommendations regarding the use of LNG-IUD should carefully weigh its potential benefits and risks. Close monitoring is advisable for the potential development of breast cancer, particularly among women with a family history of breast cancer.

Glycemic load, but not glycemic index, is associated with an increased risk of ovarian cancer: A systematic review and meta-analysis

The association between glycemic index (GI),glycemic load (GL) and ovarian cancer risk remains unclear. Carbohydrate intake promotes insulin secretion, leading to cell proliferation and invasion. We hypothesized that high GI and GL intake may increase ovarian cancer risk. Therefore, we conducted a meta-analysis after systematically searching PubMed, Embase, Web of Science, and Cochrane Library from inception to December 2022. Fixed- or random-effect models calculated the pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs). Subgroup, sensitivity, publication bias analysis, and dose-response analysis were performed. Nine original studies were included, involving 4716 cases and 119,960 controls. No significant association was observed between GI or GL and ovarian cancer risk (GI: RR = 1.02 [95% CI, 0.83-1.26]; GL: RR = 1.11 [95% CI, 0.84-1.47]). Subgroup analysis suggested the results were not significantly modified by any group. Sensitivity analysis identified the sources of heterogeneity. No publication bias was observed. A linear positive dose-response relationship was observed between dietary GL and ovarian cancer risk after removing heterogeneous sources (RR = 1.11 [95% CI, 1.05-1.17], I2 = 32.9%, P = .23 at 50 U/d; RR = 1.04 [95% CI, 1.02-1.07], I2 = 19.1%, P = .29 at 20 U/d). These outcomes suggest that high dietary GL, but not GI, is associated with significantly increased ovarian cancer risk. Thus, sufficient intake of a low dietary GL is important for reducing ovarian cancer risk.

Impact of Pre-Diagnostic Risk Factors on Short- and Long-Term Ovarian Cancer Survival Trajectories: A Longitudinal Observational Study

Tumor- and treatment-related factors are established predictors of ovarian cancer survival. New studies suggest a differential impact of exposures on ovarian cancer survival trajectories (i.e., rapidly fatal to long-term disease). This study examined the impact of pre-diagnostic risk factors on short- and long-term ovarian cancer survival trajectories in the Canadian context. This population-based longitudinal observational study included women diagnosed with invasive epithelial ovarian cancer from 1995 to 2004 in Ontario. Data were obtained from medical records, interviews, and the provincial cancer registry. Extended Cox proportional hazard models estimated the association between risk factors and all-cause and ovarian cancer-specific mortality by survival time intervals (<3 years (i.e., short-term survival), 3 to <6 years, 6 to <10 years, and ≥10 years (i.e., long-term survival)). Among 1421 women, histology, stage, and residual disease were the most important predictors of all-cause mortality in all survival trajectories, particularly for short-term survival. Reproductive and lifestyle factors did not strongly impact short-term overall survival but were associated with long-term overall survival. As such, among long-term survivors, history of breastfeeding significantly decreased the risk of all-cause mortality (HR 0.65; 95% CI 0.46, 0.93; p < 0.05), whereas smoking history (HR 1.75; 95% CI 1.27, 2.40; p < 0.05) and obesity (HR 1.81; 95% CI 1.24, 2.65; p < 0.05) significantly increased the risk of all-cause mortality. The findings were consistent with ovarian cancer-specific mortality. These findings suggest that pre-diagnostic exposures differentially influence survival time following a diagnosis of ovarian cancer.

High-grade serous carcinoma of unknown primary origin associated with STIC clinically presented as isolated inguinal lymphadenopathy: a case report

Serous tubal intraepithelial carcinoma (STIC) is a precancerous lesion of high-grade serous ovarian carcinoma (HGSOC). Usually, it arises from the fimbrial end of the tube, and it is associated with metastatic potential. On average, the time to progress from STIC to HGSOC is 6.5 years. Therefore, whenever a STIC lesion is found, surgical staging and prophylactic salpingectomy are recommended in order to prevent ovarian cancer. We report a rare case of a 45-year-old female patient who clinically presented an isolated right inguinal lymphadenopathy. The remaining clinical examination was normal. Therefore, an excisional biopsy of the lymph node was performed. Pathological analysis revealed a high-grade serous carcinoma, most likely of gynecological origin. Due to histological evidence, a computed tomography (CT) scan was carried out. There was no CT evidence of ovarian disease, pelvic involvement, intra-abdominal lymphadenopathies, metastatic disease, or ascites. All tumor markers were negative. The patient underwent laparoscopic hysterectomy and bilateral salpingo-oophorectomy followed by surgical staging. Surprisingly, pathological examination showed a STIC lesion in the fimbria of the left fallopian tube. We aim to report the potential capability of STIC to spread particularly through lymphatic pathways rather than peritoneal dissemination.

Deciphering the Therapeutic Applications of Nanomedicine in Ovarian Cancer Therapy: An Overview

The majority of deadly cancers that afflict the female reproductive system occur in the ovary. Around 1,40,000 women worldwide die from ovarian cancer each year, making it the sixth most common cancer-associated deceases among females in the United States. Modern, cutting-edge treatments like chemotherapy and surgery frequently produce full remissions, but the recurrence rate is still very high. When this crippling condition is diagnosed, there are frequently few therapeutic choices available because of how quietly it manifests. Healthcare practitioners must have a fundamental grasp of the warning signs and symptoms of ovarian cancer, as well as the imaging techniques and treatment choices available, to give the patient the best care possible. The discipline of medical nanotechnology has gained a lot of momentum in recent years in resolving issues and enhancing the detection and treatment of different illnesses, including cancer. This article gives a brief summary of types, risk factors and approaches to ovarian cancer treatment. We subsequently discussed the pathophysiology of ovarian cancer with the risk factors. This review also emphasizes the various signalling pathways involved in ovarian cancer. Our comprehensive integration of recent findings in fundamental research in the nano arena reveals the strong interest in these nanomedicines in ovarian cancer treatment. However, these nanomedicines still require more research, as indicated by the comparatively small number of clinical trials ongoing. This article will provide a reference for ovarian cancer treatment.

Imaging ovarian cancer - from baseline characteristics to high-risk image factors

BACKGROUND

Imaging ovarian cancer (OC) includes evaluating peritoneal carcinomatosis (PC) and enlarged cardio phrenic lymph nodes (CPLN) by computed tomography (CT), and thorough evaluation is tedious work. A "CT short score" with high-risk CT parameters might be a more pragmatic approach, but it is not known if such a short score associates with aggressive OC subtypes and impaired OC survival. Further, it is not known if certain established OC risk factors are linked to high-risk CT-findings which would be important in image evaluation. Herein, we investigate a CT short score and its relation to baseline characteristics, OC subtypes, and survival.

METHODS

The Malmö Diet and Cancer Study is a prospective cohort that included 17,035 women (1991-1996). Baseline characteristics and tumor information on 159 OC and information on OC specific survival (last follow-up, 2017-12-31) was registered. A CT short score (CPLN and PC-index (PCI) in seven regions) was registered and associations with clinical stage [stage I vs. advanced stage (II-IV), histological type/grade (high grade serous and endometrioid vs. other subtypes], and OC-specific survival were analyzed with logistic and Cox regression, respectively. Parity and menopausal status were analyzed in relation to short score and PCI.

RESULTS

There was an association between higher short score and advanced clinical stage (adjusted OR 2.76 (1.42-5.38)), adjusted for age at diagnosis and histological type/grade. Higher short score was associated with impaired OC specific survival (adjusted HR 1.17 (1.01-1.35)), adjusted for age at diagnosis, histological type/grade, and clinical stage. There were no significant associations between parity, menopausal status, and short score/PCI.

CONCLUSIONS

CT short score was significantly associated with advanced clinical stages and impaired OC survival. A pragmatic approach (based on CT) to evaluate high risk image findings in OC could help reduce radiologists' workload and at the same time provide structured reports to surgeons and oncologists involved in OC care.

A Nomogram for Preoperative Prediction of the Risk of Lymph Node Metastasis in Patients with Epithelial Ovarian Cancer

Objective: To develop a nomogram for predicting lymph node metastasis (LNM) in patients with epithelial ovarian cancer (EOC). Methods: Between December 2012 and August 2022, patients with EOC who received computed tomography (CT) and serological examinations and were treated with upfront staging or debulking surgery were included. Systematic pelvic and para-aortic lymphadenectomy was performed in all patients. Univariate and multivariate analysis was used to identify significant risk factors associated with LNM. A nomogram was then constructed to assess the risk of LNM, which was evaluated with respect to its area under the receiver operating characteristic curve (AUC), calibration, and clinical usefulness. Results: Of 212 patients enrolled in this study, 78 (36.8%) had positive LNs. The nomogram integrating CT-reported LN status, child-bearing status, tumour laterality, and stage showed good calibration and discrimination with an AUC of 0.775, significantly improving performance over the CT results (0.699, p = 0.0002) with a net reclassification improvement of 0.593 (p < 0.001) and integrated discrimination improvement of 0.054 (p < 0.001). The decision curve analysis showed the nomogram was of clinical use. Conclusions: A nomogram was constructed and internally validated, which may act as a decision aid in patients with EOC being considered for systemic lymphadenectomy.

Predictors of residual disease after debulking surgery in advanced stage ovarian cancer

Objective

Optimal debulking with no macroscopic residual disease strongly predicts ovarian cancer survival. The ability to predict likelihood of optimal debulking, which may be partially dependent on tumor biology, could inform clinical decision-making regarding use of neoadjuvant chemotherapy. Thus, we developed a prediction model including epidemiological factors and tumor markers of residual disease after primary debulking surgery.

Methods

Univariate analyses examined associations of 11 pre-diagnosis epidemiologic factors (n=593) and 24 tumor markers (n=204) with debulking status among incident, high-stage, epithelial ovarian cancer cases from the Nurses' Health Studies and New England Case Control study. We used Bayesian model averaging (BMA) to develop prediction models of optimal debulking with 5x5-fold cross-validation and calculated the area under the curve (AUC).

Results

Current aspirin use was associated with lower odds of optimal debulking compared to never use (OR=0.52, 95%CI=0.31-0.86) and two tissue markers, ADRB2 (OR=2.21, 95%CI=1.23-4.41) and FAP (OR=1.91, 95%CI=1.24-3.05) were associated with increased odds of optimal debulking. The BMA selected aspirin, parity, and menopausal status as the epidemiologic/clinical predictors with the posterior effect probability ≥20%. While the prediction model with epidemiologic/clinical predictors had low performance (average AUC=0.49), the model adding tissue biomarkers showed improved, but weak, performance (average AUC=0.62).

Conclusions

Addition of ovarian tumor tissue markers to our multivariable prediction models based on epidemiologic/clinical data slightly improved the model performance, suggesting debulking status may be in part driven by tumor characteristics. Larger studies are warranted to identify those at high risk of poor surgical outcomes informing personalized treatment.

A Multi-State Survival Model for Time to Breast Cancer Mortality among a Cohort of Initially Disease-Free Women

BACKGROUND

Identifying risk factors for aggressive forms of breast cancer is important. Tumor factors (e.g., stage) are important predictors of prognosis, but may be intermediates between prediagnosis risk factors and mortality. Typically, separate models are fit for incidence and mortality postdiagnosis. These models have not been previously integrated to identify risk factors for lethal breast cancer in cancer-free women.

METHODS

We combined models for breast cancer incidence and breast cancer-specific mortality among cases into a multi-state survival model for lethal breast cancer. We derived the model from cancer-free postmenopausal Nurses' Health Study women in 1990 using baseline risk factors. A total of 4,391 invasive breast cancer cases were diagnosed from 1990 to 2014 of which 549 died because of breast cancer over the same period.

RESULTS

Some established risk factors (e.g., family history, estrogen plus progestin therapy) were not associated with lethal breast cancer. Controlling for age, the strongest risk factors for lethal breast cancer were weight gain since age 18: > 30 kg versus ± 5 kg, RR = 1.94 [95% confidence interval (CI) = 1.38-2.74], nulliparity versus age at first birth (AAFB) < 25, RR = 1.60 (95% CI = 1.16-2.22), and current smoking ≥ 15 cigarettes/day versus never, RR = 1.42 (95% CI = 1.07-1.89).

CONCLUSIONS

Some breast cancer incidence risk factors are not associated with lethal breast cancer; other risk factors for lethal breast cancer are not associated with disease incidence.

IMPACT

This multi-state survival model may be useful for identifying prediagnosis factors that lead to more aggressive and ultimately lethal breast cancer.

Predictors of early mortality risk in patients with epithelial ovarian cancer

Background

To improve the overall survival of epithelial ovarian cancer (EOC) patients, a more precise risk identification after completion of standard treatment will enhance patients' follow‐up surveillance and the use of individualized targeted therapy.

Aim

This study explored the potential risk predictors of early mortality in EOC patients who had standard treatment with debulking surgery and chemotherapy.

Methods

The study included 93 EOC patients who had standard treatment and were followed up between January 2011 and December 2020. The sociodemographic, clinical, and laboratory data of patients with EOC including the update on their 3‐year follow‐up status were retrospectively collected and analyzed. Early mortality is defined as the death of a patient within 3 years of completion of standard treatment. Patients' data were computed using descriptive statistics and the associations between patients' factors and the risk of early mortality were tested using the binary logistic regression model.

Results

Early deaths occurred in 36 (38.7%) of patients with EOC. In the final multivariate analyses, early tumor relapse within 6‐months of treatment completion was the only independent risk factor that predicts early mortality in EOC patients (risk ratio = 8.6, 95% confidence interval: 3.3–24.5, p < 0.01).

Conclusion

Our study suggests that early tumor relapse may be a useful surrogate of early mortality in EOC. However, our findings should be interpreted with caution pending further corroboration through an adequately powered, prospective multicenter study.

Impact of germline mutations in cancer-predisposing genes on long-term survival in patients with epithelial ovarian cancer

BACKGROUND

Several clinical and tumour factors impact on ovarian cancer survival. It is important to evaluate if germline mutations impact long-term outcomes among patients with epithelial ovarian cancer.

METHODS

We followed 1422 Ontario women with ovarian cancer. Clinical information was obtained from medical records and vital status was determined by registry linkage. Germline genetic testing was performed for 12 susceptibility genes. We estimated 20-year cancer-specific survival according to various factors.

RESULTS

Twenty-year survival was inferior for women with serous cancers vs. other types (22.3% vs. 68.6%; P < 0.0001). Of the 1422 patients, 248 (17.4%) carried a germline mutation; 119 BRCA1; 75 BRCA2; 7 in a mismatch repair (MMR) gene and 47 in one of seven other genes. Among serous patients, 20-year survival was 28.9% for similar for women with a BRCA1 (28.9%), BRCA2 (21.2%) or no mutation (21.6%). Among endometrioid patients, 20-year survival was poor for women with a BRCA vs. no mutation (47.3% vs. 70.4%; P = 0.004). Six of the seven MMR mutation carriers are currently alive, while all three PALB2 mutation carriers died within 3 years of diagnosis. Among women with Stage III/IV serous cancers, 20-year survival was 9.4% for those with vs. 46.5% for those with no residual disease (HR = 2.91; 95% CI 2.12-4.09, P < 0.0001).

CONCLUSIONS

The most important predictor of long-term survival was no residual disease post surgery. BRCA mutation status was not predictive of long-term survival while those with MMR mutations had excellent survival. Larger studies on PALB2 carriers are needed.

Oral contraceptive use and ovarian cancer risk for BRCA1/2 mutation carriers: an international cohort study

BACKGROUND

Ovarian cancer risk in BRCA1 and BRCA2 mutation carriers has been shown to decrease with longer duration of oral contraceptive use. Although the effects of using oral contraceptives in the general population are well established (approximately 50% risk reduction in ovarian cancer), the estimated risk reduction in mutation carriers is much less precise because of potential bias and small sample sizes. In addition, only a few studies on oral contraceptive use have examined the associations of duration of use, time since last use, starting age, and calendar year of start with risk of ovarian cancer.

OBJECTIVE

This study aimed to investigate in more detail the associations of various characteristics of oral contraceptive use and risk of ovarian cancer, to provide healthcare providers and carriers with better risk estimates.

STUDY DESIGN

In this international retrospective study, ovarian cancer risk associations were assessed using oral contraceptives data on 3989 BRCA1 and 2445 BRCA2 mutation carriers. Age-dependent-weighted Cox regression analyses were stratified by study and birth cohort and included breast cancer diagnosis as a covariate. To minimize survival bias, analyses were left truncated at 5 years before baseline questionnaire. Separate analyses were conducted for each aspect of oral contraceptive use and in a multivariate analysis, including all these aspects. In addition, the analysis of duration of oral contraceptive use was stratified by recency of use.

RESULTS

Oral contraceptives were less often used by mutation carriers who were diagnosed with ovarian cancer (ever use: 58.6% for BRCA1 and 53.5% BRCA2) than by unaffected carriers (ever use: 88.9% for BRCA1 and 80.7% for BRCA2). The median duration of use was 7 years for both BRCA1 and BRCA2 carriers who developed ovarian cancer and 9 and 8 years for unaffected BRCA1 and BRCA2 carriers with ovarian cancer, respectively. For BRCA1 mutation carriers, univariate analyses have shown that both a longer duration of oral contraceptive use and more recent oral contraceptive use were associated with a reduction in the risk of ovarian cancer. However, in multivariate analyses, including duration of use, age at first use, and time since last use, duration of oral contraceptive use proved to be the prominent protective factor (compared with <5 years: 5-9 years [hazard ratio, 0.67; 95% confidence interval, 0.40-1.12]; >10 years [hazard ratio, 0.37; 95% confidence interval, 0.19-0.73]; Ptrend=.008). The inverse association between duration of use and ovarian cancer risk persisted for more than 15 years (duration of ≥10 years; BRCA1 <15 years since last use [hazard ratio, 0.24; 95% confidence interval, 0.14-0.43]; BRCA1 >15 years since last use [hazard ratio, 0.56; 95% confidence interval, 0.18-0.59]). Univariate results for BRCA2 mutation carriers were similar but were inconclusive because of limited sample size.

CONCLUSION

For BRCA1 mutation carriers, longer duration of oral contraceptive use is associated with a greater reduction in ovarian cancer risk, and the protection is long term.

High-grade serous cancer of undetermined primary origin presenting as solitary inguinal lymph node enlargement

A 62-year-old woman presented with unilateral inguinal lymphadenopathy, existing for several months. As it was initially thought to be lymphoma, the lymph node was resected. Pathology, however, revealed a metastasis of a high-grade papillary serous cancer, according to its stainings, most likely ovarian in origin. Further staging showed lymphadenopathies in the inguinofemoral, para-aortic and mediastinal regions. Consequently, the multidisciplinary oncologic meeting advised a diagnostic laparoscopy which showed no macroscopic spread within the abdomen. Pathological examination of biopsies as well as both ovaries showed no sign of ovarian cancer. The patient received standard chemotherapy, that is, carbo-Taxol-Avastin, to which she showed complete response after three cycles as shown on positron emission tomography-CT. A review of existing literature showed that this is a very unusual case of high-grade serous carcinoma, where no site of origin could be found.

Intrauterine device use and risk of ovarian cancer: Results from the New England Case-Control study and Nurses' Health Studies

Results of studies assessing intrauterine device (IUD) use and ovarian cancer risk are inconsistent. We examined the association between IUD use, including duration, type and timing of use, and ovarian cancer risk using three population-based studies. Data from the New England Case-Control Study (NEC) and two prospective cohort studies, the Nurses' Health Studies (NHS/NHSII), were included in the analysis. Information on IUD use was collected by in-person interview in NEC and by biennial questionnaire in NHS/NHSII. We used unconditional logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI) in NEC and Cox regression to calculate hazard ratios (HR) and 95% CI in NHS/NHSII. We used meta-analysis to combine the NEC and the pooled NHS/NHSII results. Overall, IUD use was not associated with epithelial ovarian cancer risk (OR = 0.96, 95% CI: 0.81-1.14 in NEC; HR = 0.89, 95% CI: 0.69-1.15 in NHS/NHSII; combined RR = 0.94, 95% CI: 0.81-1.08). Among IUD users, older age at first use was associated with increased ovarian cancer risk (P-trend = .03). We did not observe significant associations by IUD type or duration of use. In conclusion, IUD use was not associated with ovarian cancer risk in our study.

Lifestyle and reproductive health: the aetiology of ovarian cancer in Pakistan

Ovarian cancer is a fatal gynaecological cancer and eighth most common cancer in women globally. Lifestyle, reproductive and sociodemographic factors are among the influential parameters that may significantly affect the risk of ovarian cancer and its mortality rate. However, the epidemiological investigations have shown that the risk of ovarian cancers associated with these factors is different in varied geographical distributions. Lifestyle and reproductive factors have not been investigated thoroughly across a wide cultural diversity. The objective of this study is to investigate the association of these factors with ovarian cancer in Pakistan. This investigation will focus on the lifestyle effects of fat intake, intake of tea, habitual exercise, use of talc, personal hygiene, habit of holding urine for long time, obesity on ovarian cancer among Pakistani women.  Reproductive variables will include age at menarche, natural menopausal age, parity, nulliparity (miscarriages, abortion, stillbirths), infertility, fertility treatment, tubal ligation, oral contraceptive use, and family history of breast or ovarian cancer. Sociodemographic variables will include effect of age, income, education, and geographical location. A case-control study will be conducted in the major cancer hospitals of Pakistan and the patients will also be interviewed. The controls will be recruited outside the hospital. For controls the same age limit and residency requirements will be applied. The information gained from this research will be an important contribution to develop programs for health promotion, with a focus on ovarian cancer prevention and women's health. The findings could be used for health policies and planning to prevent ovarian cancer. The research will pave the way for a public policy and interventions to reduce the burden of ovarian cancer in Pakistan.

A Prospective Analysis of Circulating Plasma Metabolites Associated with Ovarian Cancer Risk

Ovarian cancer has few known risk factors, hampering identification of high-risk women. We assessed the association of prediagnostic plasma metabolites (N = 420) with risk of epithelial ovarian cancer, including both borderline and invasive tumors. A total of 252 cases and 252 matched controls from the Nurses' Health Studies were included. Multivariable logistic regression was used to estimate ORs and 95% confidence intervals (CI), comparing the 90th-10th percentile in metabolite levels, using the permutation-based Westfall and Young approach to account for testing multiple correlated hypotheses. Weighted gene coexpression network analysis (WGCNA; n = 10 metabolite modules) and metabolite set enrichment analysis (n = 23 metabolite classes) were also evaluated. An increase in pseudouridine levels from the 10th to the 90th percentile was associated with a 2.5-fold increased risk of overall ovarian cancer (OR = 2.56; 95% CI, 1.48-4.45; P = 0.001/adjusted P = 0.15); a similar risk estimate was observed for serous/poorly differentiated tumors (n = 176 cases; comparable OR = 2.38; 95% CI, 1.33-4.32; P = 0.004/adjusted P = 0.55). For nonserous tumors (n = 34 cases), pseudouridine and C36:2 phosphatidylcholine plasmalogen had the strongest statistical associations (OR = 9.84; 95% CI, 2.89-37.82; P < 0.001/adjusted P = 0.07; and OR = 0.11; 95% CI, 0.03-0.35; P < 0.001/adjusted P = 0.06, respectively). Five WGCNA modules and 9 classes were associated with risk overall at FDR ≤ 0.20. Triacylglycerols (TAG) showed heterogeneity by tumor aggressiveness (case-only heterogeneity P < 0.0001). The TAG association with risk overall and serous tumors differed by acyl carbon content and saturation. In summary, this study suggests that pseudouridine may be a novel risk factor for ovarian cancer and that TAGs may also be important, particularly for rapidly fatal tumors, with associations differing by structural features. SIGNIFICANCE: Pseudouridine represents a potential novel risk factor for ovarian cancer and triglycerides may be important particularly in rapidly fatal ovarian tumors.

Ovarian cancer risk factors by tumor aggressiveness: An analysis from the Ovarian Cancer Cohort Consortium

Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in <1 year, n = 864), very aggressive (death in 1 to < 3 years, n = 1,390), moderately aggressive (death in 3 to < 5 years, n = 639), and less aggressive (lived 5+ years, n = 1,691). Using competing risks Cox proportional hazards regression, we assessed heterogeneity of associations by tumor aggressiveness for all cases and among serous and endometrioid/clear cell tumors. Associations between parity (p_het = 0.01), family history of ovarian cancer (p_het = 0.02), body mass index (BMI; p_het ≤ 0.04) and smoking (p_het < 0.01) and ovarian cancer risk differed by aggressiveness. A first/single pregnancy, relative to nulliparity, was inversely associated with highly aggressive disease (HR: 0.72; 95% CI [0.58-0.88]), no association was observed for subsequent pregnancies (per pregnancy, 0.97 [0.92-1.02]). In contrast, first and subsequent pregnancies were similarly associated with less aggressive disease (0.87 for both). Family history of ovarian cancer was only associated with risk of less aggressive disease (1.94 [1.47-2.55]). High BMI (≥35 vs. 20 to < 25 kg/m² , 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.

Ovarian cancer risk factors by tumor aggressiveness: An analysis from the Ovarian Cancer Cohort Consortium

Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in <1 year, n = 864), very aggressive (death in 1 to < 3 years, n = 1,390), moderately aggressive (death in 3 to < 5 years, n = 639), and less aggressive (lived 5+ years, n = 1,691). Using competing risks Cox proportional hazards regression, we assessed heterogeneity of associations by tumor aggressiveness for all cases and among serous and endometrioid/clear cell tumors. Associations between parity (phet = 0.01), family history of ovarian cancer (phet = 0.02), body mass index (BMI; phet ≤ 0.04) and smoking (phet < 0.01) and ovarian cancer risk differed by aggressiveness. A first/single pregnancy, relative to nulliparity, was inversely associated with highly aggressive disease (HR: 0.72; 95% CI [0.58-0.88]), no association was observed for subsequent pregnancies (per pregnancy, 0.97 [0.92-1.02]). In contrast, first and subsequent pregnancies were similarly associated with less aggressive disease (0.87 for both). Family history of ovarian cancer was only associated with risk of less aggressive disease (1.94 [1.47-2.55]). High BMI (≥35 vs. 20 to < 25 kg/m2 , 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.

Ovarian cancer risk factors by tumor aggressiveness: An analysis from the Ovarian Cancer Cohort Consortium

Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in <1 year, n = 864), very aggressive (death in 1 to < 3 years, n = 1,390), moderately aggressive (death in 3 to < 5 years, n = 639), and less aggressive (lived 5+ years, n = 1,691). Using competing risks Cox proportional hazards regression, we assessed heterogeneity of associations by tumor aggressiveness for all cases and among serous and endometrioid/clear cell tumors. Associations between parity (p_het = 0.01), family history of ovarian cancer (p_het = 0.02), body mass index (BMI; p_het ≤ 0.04) and smoking (p_het < 0.01) and ovarian cancer risk differed by aggressiveness. A first/single pregnancy, relative to nulliparity, was inversely associated with highly aggressive disease (HR: 0.72; 95% CI [0.58-0.88]), no association was observed for subsequent pregnancies (per pregnancy, 0.97 [0.92-1.02]). In contrast, first and subsequent pregnancies were similarly associated with less aggressive disease (0.87 for both). Family history of ovarian cancer was only associated with risk of less aggressive disease (1.94 [1.47-2.55]). High BMI (≥35 vs. 20 to < 25 kg/m² , 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.

Ovarian cancer in the world: epidemiology and risk factors

Aim: Ovarian cancer is one of the most common gynecologic cancers that has the highest mortality rate. Considering the fact that knowledge on the incidence, mortality of ovarian cancer, as well as its risk factors is necessary for planning and preventing complications, this study was conducted with the aim of examining the epidemiology and risk factors of ovarian cancer in the world.

Materials and methods: In order to access the articles, Medline, Web of Science Core Collection, and Scopus databases were searched from their start to the year 2018. Full-text, English observational studies that referred to various aspects of ovarian cancer were included in the study.

Results: In total, 125 articles that had been published during the years 1925–2018 were entered into the study. Ovarian cancer is the seventh most common cancer among women. Increased risk factors of cancer have led to an upward trend in the incidence of cancer around the world. In 2018, 4.4% of entire cancer-related mortality among women was attributed to ovarian cancer. Although the incidence of cancer is higher among high Human Development Index (HDI) countries, the trend of mortality rate tends to be reversing. Various factors affect the occurrence of ovarian cancer, from which genetic factor are among the most important ones. Pregnancy, lactation, and oral contraceptive pills play a role in reducing the risk of this disease.

Conclusion: This study provides significant evidence about ovarian cancer. Considering the heavy burden of ovarian cancer on women's health, preventive measures as well as health education and early detection in high risk groups of women are highly recommended. Although some risk factors cannot be changed, a focus on preventable risk factors may reduce the risk of ovarian cancer. More studies are needed to explore the role of unclear risk factors in ovarian cancer occurrence.

Association of Combined Estrogen-Progestogen and Progestogen-Only Contraceptives with the Development of Cancer

Combined estrogen-progestogen contraceptives (oral contraceptives or OCs) and progestogen-only contraceptives (POCs) are synthetic steroids that bind to steroid hormone receptors, which are widespread throughout the body. They have a profound effect on cellular physiology. Combined OCs have been classified by the International Agency for Research on Cancer (IARC) as Group 1 carcinogens, but their findings have not been updated recently. In order to update the information and better understand the impact that OCs and POCs have on the risk of development of cancers, a comprehensive literature search was undertaken, focusing on more recently published papers. In agreement with the IARC, the recent literature confirms an increased risk of breast cancer and cervical cancer with the use of OCs. The recent literature also confirms the IARC conclusion that OCs decrease the risk of ovarian and endometrial cancers. However, there is little support from recent studies for the IARC conclusion that OCs decrease the risk of colorectal cancer or increase the risk of liver cancer. For liver cancer, this may be due to the recent studies having been performed in areas where hepatitis is endemic. In one large observational study, POCs also appear to increase the overall risk of developing cancer. OCs and POCs appear to increase the overall risk of cancer when carefully performed studies with the least intrinsic bias are considered.

Summary

OCs have been classified as cancer-causing agents, especially leading to increases in breast cancer and cervical cancer. A review of the recent scientific literature was performed to see whether this still appears to be the case. The recent literature supports the cancer-causing role of OCs especially for breast cancer and cervical cancer. Studies also indicate that progesterone-only contraceptives (such as implants and vaginal rings) also can cause cancer. This is especially true for breast cancer and cervical cancer.

Risk Model in Women with Ovarian Cancer Without Mutations

Ovarian cancer is characterised by the greatest mortality among all tumors of the reproductive tract. This study included 246 patients which consisted of 136 women with ovarian cancer without genetic mutation and 110 women with benign ovarian cysts. We created two mathematical logic models containing positive and negative risk factors of ovarian cancer such as: age at last menstruation cycle, patient age, OC, HRT, smoking, education status, and alcohol consumption. The calculated cut-off point for the first model was 0.5117. Classification determined on the basis of that cut-off point yielded 87.19% of correctly classified cases, of which 91.38% are "case" and 81.61% - "noncase". For the second model the designated cut-off point was set at 0.5149 and the percentage of correctly classified patients was 88.12%, with 92.24% correctly rated as cancer patients and 82.56% of the cases rightly recognised as having no ovarian cancer. Logit is a simple mathematical model that can be a useful tool for identification of patients with increased risk of ovarian cancer.

Sexual steroid hormone receptors profiles of ovarian carcinoma in Mexican women

The significance of the presence of androgen receptor (AR), estrogen receptor alpha (ER) and progesterone receptor (PR) in ovarian cancer patient survival has been a matter of numerous studies. This study was aimed to describe the expression profile of the three sexual steroid receptors in high-grade serous, endometrioid, mucinous and low-grade serous ovarian carcinoma and its association to the proliferation index in patients with primary ovarian carcinoma diagnosis, before any treatment. Eighty-one samples were obtained from the National Institute of Cancerology in Mexico City and were evaluated for the presence of AR, ER, PR and Ki67 by immunohistochemistry. The four subtypes of ovarian carcinoma displays a specific profile of the eight possible combinations of the steroid receptors with significant differences within the profile and the histological subtypes. High-grade serous carcinoma was characterized by a high frequency of both, triple-negative and AR+ ER- PR+ profiles. Endometrioid carcinoma presented a higher frequency of triple-positive profile. The presence of only AR+ profile was not observed in the endometrioid tumors. The relationship of the receptor profile with the proliferation index in the tumor epithelium shows that the expression of only ER is associated to a reduced proliferation index in endometrioid carcinoma. Steroid hormone receptor expression and co-expression could help characterize ovarian carcinoma.

The Chemoprevention of Ovarian Cancer: the Need and the Options

PURPOSE OF REVIEW

Ovarian cancer (OvCa) is the most lethal of all gynecological cancers, with a 5-year survival around 46%, mainly due to limitations in early diagnosis and treatment. Consequently, the chemoprevention of OvCa emerges as an important option to control this dismal disease. Here, we discuss the role of risk assessment in the design of chemoprevention strategies for OvCa, describe candidate agents, and assess future directions in this field.

RECENT FINDINGS

OvCa chemoprevention represents an opportunity for all women, especially those at high risk such as carriers of BRCA1 or BRCA2 mutations. The use of oral contraceptives confers substantial protection against OvCa including women at high risk, which increases with longer use. Despite strong evidence for their efficacy, safety concerns and the magnitude of the requisite interventional clinical trials seem to have precluded definitive studies of oral contraceptives for this application. Several other classes of drugs, including non-steroidal anti-inflammatory drugs, retinoids, angiopreventive agents, poly(ADP-ribose) polymerase inhibitors, and tyrosine kinase inhibitors have shown promise for OvCa chemoprevention.

SUMMARY

Currently, no agent is proven by interventional trials to possess chemopreventive properties against OvCa. The key opportunities in the chemoprevention of OvCa include the development of surrogate biomarkers for OvCa, the molecular definition of OvCa risk that will help select those who may benefit the most from chemoprevention, the identification of additional agents likely driven by understanding the molecular pathogenesis of OvCa, and the development of dedicated resources and support mechanisms for OvCa. Overall, there is significant optimism for the future of OvCa chemoprevention.

Disparities in cancer outcomes across age, sex, and race/ethnicity among patients with pancreatic cancer

Age, sex, and racial/ethnic disparities exist, but are understudied in pancreatic adenocarcinoma (PDAC). We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database to determine whether survival and treatment disparities persist after adjusting for demographic and clinical characteristics. Our study included PDAC patients diagnosed between 1992 and 2011. We used Cox regression to compare survival across age, sex, and race/ethnicity within early-stage and late-stage cancer subgroups, adjusting for marital status, urban location, socioeconomics, SEER region, comorbidities, stage, lymph node status, tumor location, tumor grade, diagnosis year, and treatment received. We used logistic regression to compare differences in treatment received across age, sex, and race/ethnicity. Among 20,896 patients, 84% were White, 9% Black, 5% Asian, and 2% Hispanic. Median age was 75; 56% were female and 53% had late-stage cancer. Among early-stage patients in the adjusted Cox model, older patient subgroups had worse survival compared with ages 66-69 (HR > 1.1, P < 0.01 for groups >69); no survival differences existed between sexes. Black (HR = 1.1, P = 0.01) and Hispanic (HR = 1.2, P < 0.01) patients had worse survival compared with White. Among late-stage cancer patients, patients over age 84 had worse survival than those aged 66-69 (HR = 1.1, P < 0.01), and males (HR = 1.08, P < 0.01) had worse survival than females; there were no racial/ethnic differences. Older age and minority race/ethnicity were associated with lower likelihood of receiving chemotherapy, radiation, and/or surgery. Age and racial/ethnic disparities in survival outcomes and treatment received exist for PDAC patients; these disparities persist after adjusting for differences in demographic and clinical characteristics.

The inflammatory potential of diet and ovarian cancer risk: results from two prospective cohort studies

BACKGROUND

We used a food-based empirical dietary inflammatory pattern (EDIP) score to investigate whether diets with higher inflammatory potential are associated with increased ovarian cancer risk.

METHODS

We followed 186 314 women in the Nurses' Health Study and Nurses' Health Study-II, from 1984 to 2013, to examine associations between EDIP scores and ovarian cancer risk, using Cox regression analyses.

RESULTS

During 3 454 514 person-years of follow-up, 989 ovarian cancer cases were identified. In pooled multivariable-adjusted analyses, higher EDIP scores (more pro-inflammatory diets) were not significantly associated with ovarian cancer risk (HRquintile5vs1 0.99; 95% CI: 0.80-1.22; P-trend=0.97). Similarly, we found no evidence of heterogeneity by histologic subtype (P-heterogeneity=0.52) or by tumour aggressiveness (P-heterogeneity=0.63).

CONCLUSIONS

In contrast with two previous case-control studies that found a positive association between a literature-derived nutrient-based dietary inflammatory index and ovarian cancer risk, our prospective analyses using a food-based score observed no evidence of an association.

Calcium Intake and the Risk of Ovarian Cancer: A Meta-Analysis

Several epidemiological studies have evaluated the association between calcium intake and the risk of ovarian cancer. However, the results of these studies remain controversial. Thus, we performed a meta-analysis to explore the association between calcium intake and the risk of ovarian cancer. Pubmed, Embase and Web of Science were searched for eligible publications up to April 2017. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using the random-effects model. Small-study effect was estimated using Egger's test and the funnel plot. Among 15 epidemiological studies involving 493,415 participants and 7453 cases eligible for this meta-analysis, 13 studies were about dietary calcium intake, 4 studies about dairy calcium intake and 7 studies about dietary plus supplemental calcium intake. When comparing the highest with the lowest intake, the pooled RRs of ovarian cancer were 0.80 (95% CI 0.72-0.89) for dietary calcium, 0.80 (95% CI 0.66-0.98) for dairy calcium and 0.90 (95% CI 0.65-1.24) for dietary plus supplemental calcium, respectively. Dietary calcium was significantly associated with a reduced risk of ovarian cancer among cohort studies (RR = 0.86, 95% CI 0.74-0.99) and among case-control studies (RR = 0.75, 95% CI 0.64-0.89). In subgroup analysis by ovarian cancer subtypes, we found a statistically significant association between the dietary calcium (RR = 0.78, 95% CI 0.69-0.88) and the risk of epithelial ovarian cancer (EOC). This meta-analysis indicated that increased calcium intake might be inversely associated with the risk of ovarian cancer; this still needs to be confirmed by larger prospective cohort studies.

Epidemiologic factors that predict long-term survival following a diagnosis of epithelial ovarian cancer

BACKGROUND

Various epidemiologic factors have been shown to influence the risk of ovarian cancer development. Given the high fatality associated with this disease, it is of interest to evaluate the association of prediagnostic hormonal, reproductive, and lifestyle exposures with ovarian cancer-specific survival.

METHODS

We included 1421 patients with invasive epithelial ovarian cancer diagnosed in Ontario, Canada. Clinical information was obtained from medical records and prediagnostic exposure information was collected by telephone interview. Survival status was determined by linkage to the Ontario Cancer Registry. Proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for ovarian cancer-specific mortality associated with each exposure. Analyses were stratified by histologic subtype to further investigate the associations of risk factors on ovarian cancer-specific mortality.

RESULTS

After a mean follow-up of 9.48 years (range 0.59-20.32 years), 655 (46%) women had died of ovarian cancer. Parity (ever) was associated with a significant 29% decreased mortality risk compared with nulliparity (HR=0.71; 95% CI 0.54-0.93; P=0.01). There was a borderline significant association between ever use of oestrogen-containing hormone replacement therapy (HRT) and mortality (HR=0.79; 95% CI 0.62-1.01; P=0.06). A history of cigarette smoking was associated with a significant 25% increased risk of death compared with never smoking (HR=1.25; 95% CI 1.01-1.54; P=0.04). Women with a greater cumulative number of ovulatory cycles had a significantly decreased risk of ovarian cancer-specific death (HR=0.63; 95% CI 0.43-0.94; P=0.02). Increasing BMI (kg m-2) 5 years before diagnosis was associated with an increased risk of death (HR=1.17; 95% CI 1.07-1.28; P=0.0007). Other hormonal or lifestyle factors were not significantly associated with ovarian cancer-specific mortality.

CONCLUSIONS

Parity, ovulatory cycles, smoking, and BMI may affect survival following the diagnosis of ovarian cancer. Whether or not oestrogen-containing HRT use is beneficial for survival requires further evaluation.

Hormonal and reproductive factors and the risk of ovarian cancer

PURPOSE

Hormone-related factors have been associated with ovarian cancer, the strongest being parity and oral contraceptive use. Given reductions in birth rates and increases in oral contraceptive use over time, associations in more recent birth cohorts may differ. Furthermore, consideration of ovarian cancer heterogeneity (i.e., Type I/II invasive cancers) may contribute to a better understanding of etiology. We examined hormone-related factors in relation to ovarian cancer risk overall, for Type I and Type II cancers, as well as borderline tumors.

METHODS

A population-based case-control study was carried out in Montreal, Canada from 2011 to 2016, including 496 cases and 908 controls. For each hormone-related variable, adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression for ovarian cancer overall, and using polytomous logistic regression for associations by tumor behavior and ovarian cancer type.

RESULTS

Parity was inversely associated with risk overall and by tumor behavior and type, with a stronger OR (95% CI) for Type I [0.09 (0.04-0.24) for ≥3 full-term births vs. nulliparity] vs. Type II [0.66 (0.43-1.02)] invasive cancers; the OR (95% CI) for borderline tumors was 0.41 (0.22-0.77). Oral contraceptive ever use was not associated with risk overall, but ≥10 years of use vs. never use reduced risk, particularly for invasive cancers. A history of endometriosis was most strongly associated with Type I cancers. Associations with other factors were less clear.

CONCLUSIONS

These results suggest that associations with some hormone-related factors may differ between borderline and invasive Type I and II ovarian cancers.

The association between reproductive and hormonal factors and ovarian cancer by estrogen-α and progesterone receptor status

OBJECTIVE

We assessed the association between reproductive and hormonal factors and ovarian cancer incidence characterized by estrogen receptor-α (ERα) and progesterone receptor (PR) status.

METHODS

Tissue microarrays were used to assess ERα and PR expression among 197 Nurses' Health Study (NHS), 42 NHSII and 76 New England Case-Control Study (NECC) ovarian cancer cases. NHS/NHSII cases were matched to up to 4 controls (n=954) on diagnosis date and birth year. NECC controls (n=725) were frequency matched on age. Cases were considered receptor positive if ≥1% of tumor cells stained positive. Associations by ERα and PR status were assessed using polytomous logistic regression. p-Value for heterogeneity was calculated using a likelihood ratio test.

RESULTS

45% of ovarian tumors were PR(+), 78% were ERα(+) and 45% were ERα(+)/PR(+), while 22% were ERα(-)/PR(-). Postmenopausal status was associated with an increased risk of PR(-) tumors (OR: 2.07; 95%CI: 1.15-3.75; p-heterogeneity=0.01) and age at natural menopause was inversely associated with PR(-) tumors (OR, per 5years: 0.77; 95%CI: 0.61-0.96; p-het=0.01). Increasing duration of postmenopause was differentially associated by PR status (p-het=0.0009). Number of children and tubal ligation were more strongly associated with ERα(-) versus ERα(+) tumors (p-het=0.002 and 0.05, respectively). No differential associations were observed for oral contraceptive or hormone therapy use.

CONCLUSIONS

Postmenopausal women have an increased risk of developing PR(-) ovarian tumors compared to premenopausal women. The associations observed for ovarian cancer differ from those seen for breast cancer suggesting that the biology for tumor development through ERα and PR pathways may differ.

Reproductive and hormonal factors in relation to survival and platinum resistance among ovarian cancer cases

Background:

Ovarian cancer survival is poor, particularly for platinum-resistant cases. The previous literature on pre-diagnostic reproductive factors and ovarian cancer survival has been mixed. Therefore, we evaluated pre-diagnostic reproductive and hormonal factors with overall survival and, additionally, platinum-chemotherapy resistance.

Methods:

We followed 1649 invasive epithelial ovarian cancer cases who were enrolled between 1992 and 2008 for overall mortality within the New England Case-Control Study and abstracted chemotherapy data on a subset (n=449). We assessed pre-diagnostic reproductive and hormonal factors during in-person interviews. We calculated hazard ratios (HRs) using Cox-proportional hazards models.

Results:

We observed 911 all-cause deaths among 1649 ovarian cancer cases. Self-reported endometriosis and longer duration of hormone therapy use were associated with improved survival (HR: 0.72; 95% confidence interval (CI): 0.54–0.94 and HR, ⩾5 years vs never: 0.70; 95% CI: 0.55–0.90, respectively). Older age at menopause and menarche were associated with worse survival (HR, ⩽50 vs >50 years: 1.23; 95% CI: 1.03–1.46 and HR, 13 vs <13 years: 1.24; 95% CI: 1.06–1.44, respectively). We observed no association between oral contraceptive use, parity and tubal ligation, and overall survival. No significant associations were observed for any of the reproductive and hormonal factors and platinum resistance.

Conclusions:

These results suggest that pre-diagnostic exposures such as endometriosis and HT use may influence overall survival among ovarian cancer patients.

Association of Ovarian Tumor β2-Adrenergic Receptor Status with Ovarian Cancer Risk Factors and Survival

BACKGROUND

The β₂-adrenergic signaling pathway mediates the effects of chronic stress on ovarian cancer progression in mouse models. The relevance of this pathway to human ovarian cancer remains unknown.

METHODS

We assessed tumor expression of β₂-adrenergic receptor (ADRB2) using tissue microarrays in 237 ovarian cancer cases from the Nurses' Health Studies (NHS/NHSII). Competing risks Cox regression was used to evaluate whether associations of reproductive, hormonal, and psychosocial factors with ovarian cancer risk differed by ADRB2. We also examined the association between tumor ADRB2 expression and ovarian cancer survival.

RESULTS

Forty-five (19%) cases were positive for ADRB2 staining. High levels of anxiety symptoms were positively associated with ADRB2-positive tumors (HR, 2.59; 95% confidence interval [CI], 1.15-5.84) but not with ADRB2-negative tumors (HR, 1.16; 95% CI, 0.81-1.66; P_{heterogeneity} = 0.07). We observed similar results for depression. No associations were observed for job strain, caregiving stress, or widowhood for either positive or negative ADRB2 status. Lifetime ovulatory years were more strongly associated with ADRB2-positive tumors (HR per 5 years, 1.60; 95% CI, 1.15-2.21) compared with ADRB2-negative tumors (HR, 1.11; 95% CI, 0.96-1.27; P_{heterogeneity} = 0.04). Significant heterogeneity by ADRB2 was also observed for parity (P_{heterogeneity} = 0.01), oral contraceptive use (P_{heterogeneity} = 0.03), and age at menopause (P_{heterogeneity} = 0.04). Tumor expression of ADRB2 was not associated with ovarian cancer mortality (HR, 1.05; 95% CI, 0.69-1.59).

CONCLUSIONS

Several stress- and ovulation-related factors were differentially associated with ovarian tumors responsive to β₂-adrenergic signaling.

IMPACT

Replication in larger studies is warranted to confirm the role of β₂-adrenergic signaling in ovarian cancer etiology. Cancer Epidemiol Biomarkers Prev; 25(12); 1587-94. ©2016 AACR.

Ovarian Cancer Risk Factors by Histologic Subtype: An Analysis From the Ovarian Cancer Cohort Consortium

PURPOSE

An understanding of the etiologic heterogeneity of ovarian cancer is important for improving prevention, early detection, and therapeutic approaches. We evaluated 14 hormonal, reproductive, and lifestyle factors by histologic subtype in the Ovarian Cancer Cohort Consortium (OC3).

PATIENTS AND METHODS

Among 1.3 million women from 21 studies, 5,584 invasive epithelial ovarian cancers were identified (3,378 serous, 606 endometrioid, 331 mucinous, 269 clear cell, 1,000 other). By using competing-risks Cox proportional hazards regression stratified by study and birth year and adjusted for age, parity, and oral contraceptive use, we assessed associations for all invasive cancers by histology. Heterogeneity was evaluated by likelihood ratio test.

RESULTS

Most risk factors exhibited significant heterogeneity by histology. Higher parity was most strongly associated with endometrioid (relative risk [RR] per birth, 0.78; 95% CI, 0.74 to 0.83) and clear cell (RR, 0.68; 95% CI, 0.61 to 0.76) carcinomas (P value for heterogeneity [P-het] < .001). Similarly, age at menopause, endometriosis, and tubal ligation were only associated with endometrioid and clear cell tumors (P-het ≤ .01). Family history of breast cancer (P-het = .008) had modest heterogeneity. Smoking was associated with an increased risk of mucinous (RR per 20 pack-years, 1.26; 95% CI, 1.08 to 1.46) but a decreased risk of clear cell (RR, 0.72; 95% CI, 0.55 to 0.94) tumors (P-het = .004). Unsupervised clustering by risk factors separated endometrioid, clear cell, and low-grade serous carcinomas from high-grade serous and mucinous carcinomas.

CONCLUSION

The heterogeneous associations of risk factors with ovarian cancer subtypes emphasize the importance of conducting etiologic studies by ovarian cancer subtypes. Most established risk factors were more strongly associated with nonserous carcinomas, which demonstrate challenges for risk prediction of serous cancers, the most fatal subtype.

Oral Contraceptive Use and Reproductive Characteristics Affect Survival in Patients With Epithelial Ovarian Cancer: A Cohort Study

OBJECTIVES

Prognostic risk factors influencing survival in patients with epithelial ovarian cancer (EOC) include tumor stage, grade, histologic subtype, debulking, and platinum status. Little is known about the impact of hormonal milieu and reproductive factors before cancer diagnosis on clinical outcome. We sought to evaluate whether oral contraceptive (OC) use carries any prognostic significance on overall survival (OS) in patients with EOC.

METHODS

Newly diagnosed patients with EOC, fallopian tube, and primary peritoneal cancers between 1982 and 1998 were prospectively evaluated with a comprehensive epidemiologic questionnaire. A retrospective chart review was performed to abstract clinicopathologic data, including OS. A Kaplan-Meier analysis was performed to compare survival across various exposures. A Cox regression model was used to compute adjusted hazards ratios (aHRs) and 95% confidence intervals (CIs).

RESULTS

We identified 387 newly diagnosed cancers with evaluable information in this cohort. Decreased risk of death was observed in women who reported prior use of OC (aHR, 0.79; 95% CI, 0.58-1.09), previous pregnancy (aHR, 0.77; 95% CI, 0.57-1.04), or a live birth (aHR, 0.81; 95% CI, 0.60-1.08) after adjusting for age at diagnosis, stage, and histologic subtype. Oral contraceptive use was associated with a crude reduced risk of death (HR, 0.55; 95% CI, 0.42-0.72), with reported median OS of 81 months in OC users versus 46 months in nonusers. Patients who reported a single live birth experienced the largest potential survival advantage (aHR, 0.61; 95% CI, 0.39-0.94). Oral contraceptive use and prior pregnancy were associated with improved survival across all strata.

CONCLUSIONS

Oral contraceptive use may have lasting effects on epithelial ovarian tumor characteristics conferring favorable prognosis. Putative mechanisms that affect tumor biology include complex interactions between ovarian cells, host immune cells, and hormonal microenvironment during carcinogenesis. Future efforts should be directed to determine the role of reproductive factors in antitumor immunity.

Exogenous Hormone Use: Oral Contraceptives, Postmenopausal Hormone Therapy, and Health Outcomes in the Nurses' Health Study

OBJECTIVES

To review the contribution of the Nurses' Health Study (NHS) to our understanding of the complex relationship between exogenous hormones and health outcomes in women.

METHODS

We performed a narrative review of the publications of the NHS and NHS II from 1976 to 2016.

RESULTS

Oral contraceptive and postmenopausal hormone use were studied in relation to major health outcomes, including cardiovascular disease and cancer. Current or recent oral contraceptive use is associated with a higher risk of cardiovascular disease (mainly among smokers), melanoma, and breast cancer, and a lower risk of colorectal and ovarian cancer. Although hormone therapy is not indicated primarily for chronic disease prevention, findings from the NHS and a recent analysis of the Women's Health Initiative indicate that younger women who are closer to menopause onset have a more favorable risk-benefit profile than do older women from use of hormone therapy for relief of vasomotor symptoms.

CONCLUSIONS

With updated information on hormone use, lifestyle factors, and other variables, the NHS and NHS II continue to contribute to our understanding of the complex relationship between exogenous hormones and health outcomes in women.

Biological markers of prognosis, response to therapy and outcome in ovarian carcinoma

INTRODUCTION

Ovarian cancer (OvCa) is among the most common types of cancer and is the leading cause of death from gynecological malignancies in western countries. Cancer biomarkers have a potential for improving the management of OvCa patients at every point from screening and detection, diagnosis, prognosis, follow up, response to therapy and outcome.

AREAS COVERED

The literature search has indicated a number of candidate biomarkers have recently emerged that could facilitate the molecular definition of OvCa, providing information about prognosis and predicting response to therapy. These potentially promising biomarkers include immune cells and their products, tumor-derived exosomes, nucleic acids and epigenetic biomarkers. Expert commentary: Although most of the biomarkers available today require prospective validation, the development of noninvasive liquid biopsy-based monitoring promises to improve their utility for evaluations of prognosis, response to therapy and outcome in OvCa.

Hypertension, use of antihypertensive medications, and risk of epithelial ovarian cancer

Few studies have examined the associations of hypertension and antihypertensive medications with ovarian cancer. In particular, beta-blockers, one of the most commonly prescribed medications to treat hypertension, may reduce ovarian cancer risk by inhibiting beta-adrenergic signaling. We prospectively followed 90,384 women in the Nurses' Health Study (NHS) between 1988-2012 and 113,121 NHSII participants between 1989-2011. Hypertension and use of antihypertensive medications were self-reported biennially. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). We documented 948 ovarian cancer cases during follow-up. Similar results were observed in the two cohorts. While hypertension was not associated with ovarian cancer risk (Pooled HR = 1.01; 95% CI = 0.88, 1.16), current use of any antihypertensive medication was associated with slightly increased risk compared to never users (Pooled HR = 1.18; 95% CI: 1.02, 1.37). This increased risk was primarily due to use of thiazide diuretics (Pooled HR = 1.37; 95% CI: 1.13, 1.68). No associations were observed for beta-blockers or angiotensin-converting-enzyme inhibitors. Calcium channel blockers (CCBs) were associated with suggestively reduced risk (NHS HR = 0.73; 95% CI: 0.53, 1.01), after adjusting for all antihypertensive medications. Associations were similar among hypertensive women and stronger for longer use of thiazide diuretics and CCBs. In conclusion, our results provided no evidence that beta-blockers were associated with reduced ovarian cancer risk. In contrast, we observed an increased risk for use of thiazide diuretics that should be confirmed in other studies.

Assisted reproductive techniques after fertility-sparing treatments in gynaecological cancers

BACKGROUND

The trend toward late childbearing has made fertility preservation a major issue for women who face gynecological cancer. New techniques in assisted reproductive medicine enable conception after primary treatment of these cancers. Here, we aimed to review the efficacy and safety of assisted reproductive techniques (ART) after fertility-preserving treatment of gynaecological cancers.

METHODS

We conducted a systematic literature review of both prospective and retrospective studies in the PubMed, EMBASE, CENTRAL and SciSearch databases. In the retrieved studies, we evaluated live births, clinical pregnancies, overall survival and disease-free survival.

RESULTS

We identified many prospective and retrospective studies on this topic, but no relevant randomized clinical trials. Fertility-sparing treatments with safe oncological outcomes are feasible in endometrial, cervical and ovarian cancer cases. After cancer treatment, ART seem safe and show variable obstetrical outcomes.

CONCLUSIONS

After fertility-preserving treatment for gynaecological cancers, ART can enable pregnancy to be achieved with apparent oncological safety. The success of such procedures should directly impact clinical practice and management of those patients who require fertility-sparing treatment.

Statistical methods for studying disease subtype heterogeneity

A fundamental goal of epidemiologic research is to investigate the relationship between exposures and disease risk. Cases of the disease are often considered a single outcome and assumed to share a common etiology. However, evidence indicates that many human diseases arise and evolve through a range of heterogeneous molecular pathologic processes, influenced by diverse exposures. Pathogenic heterogeneity has been considered in various neoplasms such as colorectal, lung, prostate, and breast cancers, leukemia and lymphoma, and non-neoplastic diseases, including obesity, type II diabetes, glaucoma, stroke, cardiovascular disease, autism, and autoimmune disease. In this article, we discuss analytic options for studying disease subtype heterogeneity, emphasizing methods for evaluating whether the association of a potential risk factor with disease varies by disease subtype. Methods are described for scenarios where disease subtypes are categorical and ordinal and for cohort studies, matched and unmatched case-control studies, and case-case study designs. For illustration, we apply the methods to a molecular pathological epidemiology study of alcohol intake and colon cancer risk by tumor LINE-1 methylation subtypes. User-friendly software to implement the methods is publicly available.

Risk prediction model for epithelial ovarian cancer using molecular markers and clinical characteristics

BACKGROUND

A high-quality risk prediction model is urgently needed for the clinical management of ovarian cancer. However most existing models are solely based on clinical parameters, and molecular classifications in recent reports are still being debated. This study aimed to establish a risk prediction model by using both clinicopathological and molecular factors (the synthetic model) for epithelial ovarian cancer.

METHODS

A retrospective cohort study was conducted in epithelial ovarian cancer patients (n = 161) treated with primary debulking surgery and adjuvant chemotherapy. The expression level of 15 selected molecular markers were measured using immunohistochemistry. A risk model was developed using COX regression analysis with overall survival as the primary outcome. A simplified scoring system for each prognostic factor was based on its coefficient. Independent validation (n = 40) was conducted to evaluate the performance of the model.

RESULTS

A total of 10 out of 15 molecular markers were significantly associated with clinical characteristics and overall survival. The synthetic model performed better than the clinicopathological risk model or the molecular risk model alone, as assessed by analysis of the receiver-operating characteristics curve area and the Youden index. The synthetic model included parity (>3), peritoneal metastasis, stage, tumor type, residual disease, and expression of human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR), breast cancer 1 (BRCA1), murine sarcoma viral oncogene homolog B (BRAF) and Kirsten rat sarcoma viral oncogene homolog (KRAS).

CONCLUSIONS

Our synthetic risk model may more accurately predict survival of epithelial ovarian cancer patients than current models.

Prior oral contraceptive use in ovarian cancer patients: assessing associations with overall and progression-free survival

Background

Prior studies have described a reduced risk of developing ovarian cancer with the use of oral contraceptives. In this context, we decided to examine if oral contraceptive use prior to a diagnosis of ovarian cancer is associated with better overall and progression-free survival.

Methods

This retrospective cohort study included ovarian cancer patients who were seen at the Mayo Clinic in Rochester, Minnesota from 2000 through 2013. Patients completed a risk factor questionnaire about previous oral contraceptive use, and clinical data were extracted from the electronic medical record.

Results

A total of 1398 ovarian cancer patients responded to questions on oral contraceptive use; 571 reported no prior use with all others having responded affirmatively to oral contraceptive use. Univariate analyses found that oral contraceptive use (for example, ever versus never) was associated with better overall survival (hazard ratio (HR) 0.73 (95 % confidence interval (CI): 0.62, 0.86); p = 0.0002) and better progression-free survival (HR 0.71 (95 % CI: 0.61, 0.83); p < 0.0001). In multivariate analyses, contraceptive use continued to yield a favorable, statistically significant association with progression-free survival, but such was not the case with overall survival.

Conclusions

This study suggests that previous oral contraceptive use is associated with improved progression-free survival in patients diagnosed with ovarian cancer.

Reproductive and hormone-related risk factors for epithelial ovarian cancer by histologic pathways, invasiveness and histologic subtypes: Results from the EPIC cohort

Whether risk factors for epithelial ovarian cancer (EOC) differ by subtype (i.e., dualistic pathway of carcinogenesis, histologic subtype) is not well understood; however, data to date suggest risk factor differences. We examined associations between reproductive and hormone-related risk factors for EOC by subtype in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Among 334,126 women with data on reproductive and hormone-related risk factors (follow-up: 1992-2010), 1,245 incident cases of EOC with known histology and invasiveness were identified. Data on tumor histology, grade, and invasiveness, were available from cancer registries and pathology record review. We observed significant heterogeneity by the dualistic model (i.e., type I [low grade serous or endometrioid, mucinous, clear cell, malignant Brenner] vs. type II [high grade serous or endometrioid]) for full-term pregnancy (phet  = 0.02). Full-term pregnancy was more strongly inversely associated with type I than type II tumors (ever vs. never: type I: relative risk (RR) 0.47 [95% confidence interval (CI): 0.33-0.69]; type II, RR: 0.81 [0.61-1.06]). We observed no significant differences in risk in analyses by major histologic subtypes of invasive EOC (serous, mucinous, endometrioid, clear cell). None of the investigated factors were associated with borderline tumors. Established protective factors, including duration of oral contraceptive use and full term pregnancy, were consistently inversely associated with risk across histologic subtypes (e.g., ever full-term pregnancy: serous, RR: 0.73 [0.58-0.92]; mucinous, RR: 0.53 [0.30-0.95]; endometrioid, RR: 0.65 [0.40-1.06]; clear cell, RR: 0.34 [0.18-0.64]; phet  = 0.16). These results suggest limited heterogeneity between reproductive and hormone-related risk factors and EOC subtypes.

Proceedings of the second international molecular pathological epidemiology (MPE) meeting

Disease classification system increasingly incorporates information on pathogenic mechanisms to predict clinical outcomes and response to therapy and intervention. Technological advancements to interrogate omics (genomics, epigenomics, transcriptomics, proteomics, metabolomics, metagenomics, interactomics, etc.) provide widely open opportunities in population-based research. Molecular pathological epidemiology (MPE) represents integrative science of molecular pathology and epidemiology. This unified paradigm requires multidisciplinary collaboration between pathology, epidemiology, biostatistics, bioinformatics, and computational biology. Integration of these fields enables better understanding of etiologic heterogeneity, disease continuum, causal inference, and the impact of environment, diet, lifestyle, host factors (including genetics and immunity), and their interactions on disease evolution. Hence, the Second International MPE Meeting was held in Boston in December 2014, with aims to: (1) develop conceptual and practical frameworks; (2) cultivate and expand opportunities; (3) address challenges; and (4) initiate the effort of specifying guidelines for MPE. The meeting mainly consisted of presentations of method developments and recent data in various malignant neoplasms and tumors (breast, prostate, ovarian and colorectal cancers, renal cell carcinoma, lymphoma, and leukemia), followed by open discussion sessions on challenges and future plans. In particular, we recognized need for efforts to further develop statistical methodologies. This meeting provided an unprecedented opportunity for interdisciplinary collaboration, consistent with the purposes of the Big Data to Knowledge, Genetic Associations and Mechanisms in Oncology, and Precision Medicine Initiative of the US National Institute of Health. The MPE meeting series can help advance transdisciplinary population science and optimize training and education systems for twenty-first century medicine and public health.

A prospective cohort study of dietary indices and incidence of epithelial ovarian cancer

BACKGROUND

Several dietary indices have been developed to measure overall diet quality, including the Healthy Eating Index-2005 (HEI-2005), which measures adherence to the 2005 Dietary Guidelines from the USDA; the Alternative Healthy Eating Index-2010 (AHEI-2010), which is based on foods and nutrients predictive of chronic disease risk; and the Alternate Mediterranean Diet Score (aMDS), which is an index that characterizes traditional food patterns of Mediterranean countries. Few studies have evaluated diet quality and ovarian cancer risk.

METHODS

We assessed the associations of the HEI-2005, AHEI-2010, and aMDS with risk of epithelial ovarian cancer prospectively among women in the Nurses' Health Study. We used Cox proportional hazards models, adjusting for known ovarian cancer risk factors.

RESULTS

During 24 years of follow-up, we documented 696 incident epithelial ovarian cancer cases among 82,948 women with diet information. The multivariate adjusted hazard ratios (95% confidence interval; Ptrend) of epithelial ovarian cancer comparing the highest with the lowest quintile were 1.03 (0.80-1.34; 0.77) for the AHEI-2010, 0.85 (0.65-1.12; 0.57) for the HEI-2005, and 0.91 (0.71-1.18; 0.44) for the aMDS.

CONCLUSIONS

We did not observe any clear association of three diet quality scores with ovarian cancer risk. Further work should other metrics of evaluating diet quality that may be more relevant cancer risk.

Intake of dietary flavonoids and risk of epithelial ovarian cancer

BACKGROUND

The impact of different dietary flavonoid subclasses on risk of epithelial ovarian cancer is unclear, with limited previous studies that have focused on only a few compounds.

OBJECTIVE

We prospectively examined associations between habitual flavonoid subclass intake and risk of ovarian cancer.

DESIGN

We followed 171,940 Nurses' Health Study and Nurses' Health Study II participants to examine associations between intakes of total flavonoids and their subclasses (flavanones, flavonols, anthocyanins, flavan-3-ols, flavones, and polymeric flavonoids) and risk of ovarian cancer by using Cox proportional hazards models. Intake was calculated from validated food-frequency questionnaires collected every 4 y.

RESULTS

During 16-22 y of follow-up, 723 cases of ovarian cancer were confirmed through medical records. In pooled multivariate-adjusted analyses, total flavonoids were not statistically significantly associated with ovarian cancer risk (HR for the top compared with the bottom quintile: 0.85; 95% CI: 0.66, 1.09; P-trend = 0.17). However, participants in the highest quintiles of flavonol and flavanone intakes had modestly lower risk of ovarian cancer than did participants in the lowest quintile, although the P-trend was not significant [HRs: 0.76 (95% CI: 0.59, 0.98; P-trend = 0.11) and 0.79 (95% CI: 0.63,1.00; P-trend = 0.26), respectively]. The association for flavanone intake was stronger for serous invasive and poorly differentiated tumors (comparable HR: 0.68; 95% CI: 0.50, 0.92; P-heterogeneity = 0.10, P-trend = 0.07) compared with nonserous and less-aggressive tumors. Intakes of other subclasses were not significantly associated with risk. In food-based analyses used to compare subjects who consumed >1 and ≤ 1 cup black tea/d, the HR was 0.68 (95% CI: 0.51, 0.90; P < 0.01).

CONCLUSIONS

Higher intakes of flavonols and flavanones as well as black tea consumption may be associated with lower risk of ovarian cancer. Additional prospective studies are required to confirm these findings.

Menstrual pain and epithelial ovarian cancer risk

PURPOSE

Menstrual pain is associated with increased production of inflammatory molecules, such as prostaglandins. Inflammation is involved in pathogenesis of several cancers, including ovarian cancer. In this study, we examined the association between menstrual pain and risk of ovarian cancer.

METHODS

We conducted a case-control study with 2,028 cases of epithelial ovarian cancer and 2,091 age- and study center-matched controls. Women were asked to report the severity of menstrual pain during their twenties and thirties, when not using oral contraceptives or breastfeeding. We used an unconditional logistic regression to evaluate the association between menstrual pain and epithelial ovarian cancer risk overall, and polytomous logistic regression to evaluate whether the association differed across tumor subtypes.

RESULTS

Risk of ovarian cancer was increased in women with moderate (OR 1.22, 95 % CI 1.05-1.42) and severe pain (OR 1.34, 95 % CI 1.09-1.65) compared to women with no or mild pain during menstrual period. The association differed by histologic subtypes, with significant associations for severe pain with endometrioid (OR 1.64, 95 % CI 1.15-2.34) and clear cell tumors (OR 1.91, 95 % CI 1.11-3.28).

CONCLUSIONS

Our data suggest that moderate and severe pain during menstrual period are associated with increased risk of epithelial ovarian cancer. Due to high prevalence of menstrual pain in women of reproductive age, this observation warrants further studies.

Dairy food and nutrient intake in different life periods in relation to risk of ovarian cancer

PURPOSE

High lactose intake has been suggested to increase epithelial ovarian cancer (EOC) risk. We evaluated the association between lactose consumed during specific life periods (high school, premenopause, and postmenopause) and later risk of EOC.

METHODS

We assessed the association of dairy food and nutrient intake with risk of EOC during 28 years of follow-up including 764 cases in the Nurses' Health Study (NHS) and NHSII. Cox proportional hazards regression was used to model the hazard ratios (HRs) and 95% confidence intervals (CIs) for EOC across categories of dairy food or nutrient intake. We examined dietary intake in adulthood overall, as well as during premenopausal/postmenopausal years and high school.

RESULTS

In analyses of the highest versus lowest cumulative average intake in adulthood, we observed a non-significant inverse association with skim milk intake (HR 0.76, 95% CI 0.54-1.06, p(trend) = 0.05), a non-significant inverse association with lactose intake (HR 0.87, 95% CI 0.69-1.11, p(trend) = 0.22) and no association with consumption of whole milk, dairy calcium, or dairy fat. Similar risk estimates were observed for dairy food/nutrient intake during high school, premenopause or postmenopause. Lactose intake in adulthood was inversely associated with risk of endometrioid EOC (HR 0.32, 95% CI 0.16-0.65, p(trend) < 0.001).

CONCLUSIONS

These findings do not support the hypothesis that higher lactose intake increases EOC risk. The inverse association with endometrioid tumors deserves further study.