Prediagnosis food patterns are associated with length of survival from epithelial ovarian cancer

Abstract

Background: Dietary factors have been the focus of many studies on the etiology of ovarian cancer and may potentially affect survival. Indeed, three recent studies outside the United States have suggested that diet plays a role in ovarian cancer survival.

Objective: The study purpose was to evaluate the hypothesis that women diagnosed with ovarian cancer whose reported prediagnosis food patterns more closely reflect recommendations for optimal health experience a survival advantage compared with those reporting poorer diets.

Design: A longitudinal follow-up study design was used to examine prediagnosis usual diet effects on survival among 341 Cook County, Illinois, residents diagnosed with epithelial ovarian cancer during 1994-1998. These women participated in a previous case-control study where diet was assessed using a validated food frequency questionnaire. This diet information was categorized utilizing the Dietary Guidelines for Americans 2005. Deaths through 2005 were ascertained using a national death index search.

Statistical analysis: Hazard ratios (HR) and 95% confidence intervals (CI) adjusting for important covariables were obtained from proportional hazards regression models to evaluate diet effects on survival from ovarian cancer.

Results: Comparisons of high to low food group or subgroup intakes demonstrated statistically significant prediagnosis food pattern associations with survival time. Longer survival was associated with total fruits and vegetables (HR 0.61, 95% CI 0.38 to 0.98, P for trend=0.10) and vegetables separately (HR 0.66, 95% CI 0.43 to 1.01, P for trend <0.05). Subgroup analyses showed only yellow and cruciferous vegetables to significantly favor survival. Conversely, a survival disadvantage was shown for meats, not generally recommended (HR 2.28, 95% CI 1.34 to 3.89, P for trend <0.01), and specifically the red and cured/processed meats subgroups. An increased HR was also observed for the milk (all types) subgroup (HR 2.15, 95% CI 1.20 to 3.84, P for trend <0.05).

Conclusions: Prediagnosis adherence to diets that reflect recommendations for optimal nutrition and cancer prevention may have benefits that continue even after an ovarian cancer diagnosis.