Abstract 4806: Daily coffee drinking reduces gastric cancer risk among Singapore Chinese women.
Authors: Ainslie-Waldman Cheryl E. , Butler Lesley M. , Koh Woon-Puay , Wang Renwei , Yuan Jian-Min 
Published: August 2014

Abstract
BACKGROUND Gastric cancer is among the deadliest cancers in the world. Gastric cancer incidence is highest among Asian populations. Numerous cell and animal studies have demonstrated chemopreventive effects of coffee, one of the most widely consumed beverages worldwide. Chinese in Singapore are one of the few Asian populations that drink coffee. There are few prospective data among Asians that have explored the effect of coffee drinking on gastric cancer risk.
METHODS We examined the association between dietary factors, including coffee and caffeine, and the risk of gastric cancer in the population-based prospective cohort of the Singapore Chinese Health Study. At baseline, dietary information was ascertained with a validated food frequency questionnaire. Incident gastric cancer cases (n=519) were identified from 61,321 men and women after a mean follow-up of 12.4 years. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for the relationship between coffee and gastric cancer risk using Cox proportional hazards regression after adjustment for potential confounders, including smoking history and alcohol use. Secondary analyses were conducted with stratification by gender and subsite of gastric cancer (cardia, non-cardia, or unspecified).
RESULTS In the overall cohort, daily or more frequent coffee consumption was associated with a statistically non-significant decrease in gastric cancer risk (HR=0.83; 95% CI: 0.63, 1.08), compared to monthly or no consumption. When the analysis was confined to women, the inverse association strengthened and became statistically significant with adjustment for caffeine intake (HR=0.56; 95% CI: 0.36, 0.88; P for trend=0.004). In analyses among women, further stratification by duration of follow-up revealed that the inverse association with daily coffee intake was confined to those with longer follow-up (e.g., ≥7 years) (HR=0.40; 95% CI: 0.22, 0.75), compared with never/monthly coffee intake. There was no association with coffee intake and gastric cancer among men. Overall and gender-stratified analyses for coffee and gastric cancer risk did not differ by gastric cancer subsite.
CONCLUSIONS We provide results from the first prospective analyses of coffee intake and gastric cancer risk among an Asian population. We report that moderate coffee consumption was associated with a statistically significant 44% reduction in gastric cancer risk among Singapore Chinese women, regardless of caffeine intake. The effect appears strongest among women with a longer period of follow-up, suggesting that coffee may exert its protective effects during the earlier stages of gastric cancer development. Further research is needed to determine why the protective effect of coffee on gastric cancer risk may be isolated to women.
Citation Format: Cheryl E. Ainslie-Waldman, Lesley M. Butler, Woon-Puay Koh, Renwei Wang, Jian-Min Yuan. Daily coffee drinking reduces gastric cancer risk among Singapore Chinese women. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4806. doi:10.1158/1538-7445.AM2013-4806