Pre-diagnosis diet and survival after a diagnosis of ovarian cancer

Background: The relationship between diet and survival after ovarian cancer diagnosis is unclear as a result of a limited number of studies and inconsistent findings. Methods: We examined the association between pre-diagnostic diet and overall survival in a population-based cohort (n = 811) of Australian women diagnosed with invasive epithelial ovarian cancer between 2002 and 2005. Diet was measured by validated food frequency questionnaire. Deaths were ascertained up to 31 August 2014 via medical record review and Australian National Death Index linkage. We conducted Cox proportional hazards regression analysis, controlling for diagnosis age, tumour stage, grade and subtype, residual disease, smoking status, body mass index, physical activity, marital status, and energy intake. Results: We observed improved survival with highest compared with lowest quartile of fibre intake (hazard ratio (HR) = 0.69, 95% CI: 0.53-0.90, P-trend = 0.002). There was a suggestion of better survival for women with highest compared with lowest intake category of green leafy vegetables (HR = 0.79, 95% CI: 0.62-0.99), fish (HR = 0.74, 95% CI: 0.57-0.95), poly-to mono-unsaturated fat ratio (HR = 0.76, 95% CI: 0.59-0.98), and worse survival with higher glycaemic index (HR = 1.28, 95% CI: 1.01-1.65, P-trend = 0.03). Conclusions: The associations we observed between healthy components of diet pre-diagnosis and ovarian cancer survival raise the possibility that dietary choices after diagnosis may improve survival.