Diet and survival after a diagnosis of ovarian cancer: a pooled analysis from the Ovarian Cancer Association Consortium

Background: Prognosis after a diagnosis of invasive epithelial ovarian cancer is poor. Some studies have suggested modifiable behaviors, like diet, are associated with survival but the evidence is inconsistent. Objectives: This study aims to pool data from studies conducted around the world to evaluate the relationships among dietary indices, foods, and nutrients from food sources and survival after a diagnosis of ovarian cancer. Methods: This analysis from the Multidisciplinary Ovarian Cancer Outcomes Group within the Ovarian Cancer Association Consortium included 13 studies with 7700 individuals with ovarian cancer, who completed food-frequency questionnaires regarding their prediagnosis diet. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CI) for associations with overall survival were estimated using Cox proportional hazards models. Results: Overall, there was no association between any of the 7 dietary indices (representing prediagnosis diet) evaluated and survival; however, associations differed by tumor stage. Although there were no consistent associations among those with advanced disease, among those with earlier stage (local/regional) disease, higher scores on the alternate Healthy Eating Index (aHR quartile 4 compared with 1 = 0.66, 95% CI: 0.50, 0.87), Healthy Eating Index-2015 (aHR: 0.75; 95% CI: 0.59, 0.97), and alternate Mediterranean diet (aHR: 0.76; 95% CI: 0.60, 0.98) were associated with better survival. Better survival was also observed for individuals with early-stage disease who reported higher intakes of dietary components that contribute to the healthy diet indices (aHR for Q4 compared with Q1: vegetables 0.71; 95% CI: 0.56, 0.91), tomatoes (aHR: 0.72; 95% CI: 0.57, 0.91) and nuts and seeds (aHR 0.71; 95% CI: 0.55, 0.92). In contrast, there were suggestions of worse survival with higher scores on 2 of the 3 inflammatory indices and higher intake of trans-fatty acids. Conclusions: Adherence to a more healthy, less-inflammatory diet may confer a survival benefit for individuals with early-stage ovarian cancer.