Green tea consumption enhances survival of epithelial ovarian cancer

Abstract

Our study investigates whether tea consumption can enhance the survival of patients with epithelial ovarian cancer, a prospective cohort study was conducted in Hangzhou, China. The cohort comprised 254 patients recruited during 1999-2000 with histopathologically confirmed epithelial ovarian cancer and was followed up for a minimum of 3 years. Two hundred forty four (96.1%) of the cohort or their close relatives were traced. The variables examined included their survival time and the frequency and quantity of tea consumed post-diagnosis. The actual number of deaths was obtained and Cox proportional hazards models were used to obtain hazard ratios and associated 95% confidence intervals (CI), adjusting for age at diagnosis, locality, BMI, parity, FIGO stage, histologic grade of differentiation, cytology of ascites, residual tumour and chemotherapeutic status. The survival experience was different between tea drinkers and non-drinkers (p < 0.001). There were 81 (77.9%) of 104 tea-drinkers who survived to the time of interview, compared to only 67 women (47.9%) still alive among the 140 non-drinkers. Compared to non-drinkers, the adjusted hazard ratios were 0.55 (95% CI = 0.34-0.90) for tea-drinkers, 0.43 (95% CI = 0.20-0.92) for consuming at least 1 cup of green tea/day, 0.44 (95% CI = 0.22-0.90) for brewing 1 batch or more of green tea/day, 0.40 (95% CI = 0.18-0.90) for consuming more than 500 g of dried tea leaves/year, and 0.38 (95% CI = 0.15-0.97) for consuming at least 2 g of dried tea leaves/batch. The corresponding dose-response relationships were significant (p < 0.05). We conclude that increasing the consumption of green tea post-diagnosis may enhance epithelial ovarian cancer survival.