Dietary Fats and All-cause and Breast Cancer–specific Mortality among Women with Breast Cancer: The Western New York Exposures and Breast Cancer Study

Background: Study results of prediagnostic dietary fat intake and by menopausal status, estrogen receptor (ER) status, and tumor breast cancer mortality have been inconclusive. While dietary fat stage were examined. subtypes [saturated (SFA), polyunsaturated (PUFA), and mono-Results: Median follow-up time was 18.75 years; 327 (41.2%) unsaturated (MUFA) fatty acids] may have different biological participants had died. Compared with lower intake, greater intake of effects, there is little evidence regarding the association of dietary total fat (HR, 1.05; 95% CI, 0.65–1.70), SFA (1.31; 0.82–2.10), fat and fat subtype intake with mortality after breast cancer MUFA (0.99; 0.61–1.60), and PUFA (0.99; 0.56–1.75) was not diagnosis. associated with breast cancer–specific mortality. There was also no Methods: Women with incident, pathologically confirmed invaassociation with all-cause mortality. Results did not vary by mensive breast cancer and complete dietary data (n ¼ 793) were opausal status, ER status, or tumor stage. followed in a population-based study, the Western New York Conclusions: Prediagnostic intake of dietary fat and fat subtypes Exposures and Breast Cancer study. Usual intake before diagnosis was not associated with either all-cause or breast cancer mortality in of total fat and subtypes were estimated from a food frequency a population-based cohort of breast cancer survivors. questionnaire completed at baseline. HRs and 95% confidence Impact: Understanding factors affecting survival among women intervals (CI) for all-cause and breast cancer–specific mortality diagnosed with breast cancer is critically important. Dietary fat were estimated with Cox proportional hazards models. Interactions intake prior to diagnosis may not impact that survival.