Abstract B30: Dietary fat intake and ovarian cancer risk.

Abstract

Abstract Purpose: Prevention recommendations for ovarian cancer have been limited because few confirmed risk factors are modifiable. While dietary fat intake has been proposed as a potential risk factor, results have been inconsistent possibly due to limitations of when diet was assessed (e.g., baseline only). Therefore, in two large prospective cohort studies, we examined the association between ovarian cancer risk and dietary fat intake, including cumulative average intake (long-term intake) as well as simple updated intake (recent intake). Methods: We assessed recent (2-6 years prior to diagnosis) as well as long-term (cumulative average) dietary fat intake among 65,590 women in the Nurses' Health Study (NHS) and NHSII using food frequency questionnaires administered every 2-4 years beginning in 1984 and 1991 respectively. We examined intakes of total fat as well as specific types of fat (i.e., animal, vegetable, saturated, monounsaturated, polyunsaturated, and trans fat). We identified 536 cases of ovarian cancer throughout follow-up with information on recent diet. We used Cox proportional hazards regression to estimate the associations between dietary fat intake and risk of ovarian cancer. Results: While recent total fat intake was not associated with ovarian cancer risk (RR comparing extreme quartiles= 1.05, 95%CI: 0.81-1.36), higher recent polyunsaturated fat intake was associated with a higher risk of ovarian cancer (RR comparing extreme quartiles=1.45, 95%CI: 1.08-1.94). However, there were no significant associations between cumulative average intakes of dietary fat and risk of ovarian cancer. For example, women in the highest quartile of cumulative average polyunsaturated fat intake had a non-significant 20% higher risk of ovarian cancer compared to those in the lowest quartile (95%CI: 0.88-1.62, p-trend=0.39). Conclusion: While there were no significant associations between long-term dietary fat intake and risk of ovarian cancer in the NHS and NHSII, higher recent intake of polyunsaturated fat was associated with a higher risk of ovarian cancer. Future work will assess whether these associations vary histologic subtypes and by ER and PR expression in ovarian tumors. Citation Format: Megan Rice, Shelley Tworoger. Dietary fat intake and ovarian cancer risk. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr B30.