Kate Gersekowski

Green tea consumption, primary treatment outcome and survival after a diagnosis of ovarian cancer

Background Drinking green tea prior to a diagnosis of ovarian cancer has been associated with improved survival; however, research on post-diagnosis consumption is limited. We investigated whether consuming green tea during primary chemotherapy was associated with improved treatment response and whether green tea drinking pre-diagnosis or post-treatment was associated with survival. Methods We used data from the Ovarian Cancer Prognosis and Lifestyle study, an Australian prospective cohort of 958 women with epithelial ovarian cancer. Tea consumption was self-reported at baseline and at 3 monthly intervals following diagnosis. Logistic regression was used to estimate ORs and 95% CIs for the association between green tea consumption during primary treatment and outcome. Flexible parametric survival models were used to estimate HRs and 95% CIs for the associations between green tea pre-diagnosis and post-treatment and survival. Black and herbal tea were included as negative controls. Results No association was seen between green or black tea consumption during chemotherapy and treatment response. There was a suggestion that drinking at least one cup/day of green tea in the pre-diagnosis or post-treatment periods was associated with improved overall survival (pre-diagnosis: HR=0.78, 95%CI=0.60 to 1.00; post-treatment: HR=0.84, 95%CI=0.66 to 1.04), but not progression-free survival. Conversely, herbal tea consumption post-treatment was associated with improved progression-free but not overall survival. Conclusions We confirmed previous results suggesting green tea may be associated with better ovarian cancer survival but cannot rule out the possibility that residual confounding may be influencing these associations. Randomised trials are required to confirm any potential benefit.

Risk Factors for Ovarian Cancer by BRCA Status: A Collaborative Case-Only Analysis

Abstract Background: Women with an inherited pathogenic variant in BRCA1 or BRCA2 have a greatly increased risk of developing ovarian cancer, but the importance of behavioral factors is less clear. We used a case-only design to compare the magnitude of associations with established reproductive, hormonal, and lifestyle risk factors between BRCA mutation carriers and noncarriers. Methods: We pooled data from five studies from the Ovarian Cancer Association Consortium including 637 BRCA carriers and 4,289 noncarriers. Covariate-adjusted generalized linear mixed models were used to estimate interaction risk ratios (IRR) and 95% confidence intervals (CI), with BRCA (carrier vs. noncarrier) as the response variable. Results: IRRs were above 1.0 for known protective factors including ever being pregnant (IRR = 1.29, 95% CI; 1.00–1.67) and ever using the oral contraceptive pill (1.30, 95% CI; 1.07–1.60), suggesting the protective effects of these factors may be reduced in carriers compared with noncarriers. Conversely, the IRRs for risk factors including endometriosis and menopausal hormone therapy were below 1.0, suggesting weaker positive associations among BRCA carriers. In contrast, associations with lifestyle factors including smoking, physical inactivity, body mass index, and aspirin use did not appear to differ by BRCA status. Conclusions: Our results suggest that associations with hormonal and reproductive factors are generally weaker for those with a pathogenic BRCA variant than those without, while associations with modifiable lifestyle factors are similar for carriers and noncarriers. Impact: Advice to maintain a healthy weight, be physically active, and refrain from smoking will therefore benefit BRCA carriers as well as noncarriers.

Folate Intake and Ovarian Cancer Risk among Women with Endometriosis: A Case–Control Study from the Ovarian Cancer Association Consortium

Abstract Background: Although folate intake has not been associated with an increased risk of ovarian cancer overall, studies of other cancer types have suggested that high folate intake may promote carcinogenesis in precancerous lesions. Women with endometriosis (a potential precancerous lesion) have an increased risk of developing ovarian cancer; however, whether high folate intake increases risk in this group is unknown. Methods: We conducted a pooled analysis of six case–control studies from the Ovarian Cancer Association Consortium to investigate the association between folate intake and risk of ovarian cancer among women with and without self-reported endometriosis. We included 570 cases/558 controls with and 5,171/7,559 without endometriosis. We used logistic regression to estimate odds ratios (OR) and 95% confidence intervals for the association between folate intake (dietary, supplemental, and total) and ovarian cancer risk. Finally, we used Mendelian randomization (MR) to evaluate our results using genetic markers as a proxy for folate status. Results: Higher dietary folate intake was associated with an increased risk of ovarian cancer for women with endometriosis [OR, 1.37 (1.01–1.86)] but not for women without endometriosis. There was no association between supplemental folate intake and ovarian cancer risk for women with or without endometriosis. A similar pattern was seen using MR. Conclusions: High dietary folate intake may be associated with an increased risk of ovarian cancer among women with endometriosis. Impact: Women with endometriosis with high folate diets may be at increased risk of ovarian cancer. Further research is needed on the potential cancer-promoting effects of folate in this group.