Coffee consumption and risk of endometrial cancer: A prospective study in Japan

Abstract

Coffee has been proposed to decrease the circulating insulin and estrogen levels, which are related to the development of endometrial cancer. However, few studies have prospectively assessed the association between coffee consumption and endometrial cancer. We conducted a population-based prospective cohort study in 53,724 Japanese women aged 40-69 years with no history of cancer at baseline in 1990-1994. We used Cox proportional hazards regression analysis to estimate the hazard ratio (HR) and 95% confidence interval (CI) of endometrial cancer incidence in relation to coffee consumption. All reported p values are 2-tailed. During the 15-year follow-up period, we documented 117 cases of endometrial cancer. Coffee consumption was significantly associated with a decreased risk of endometrial cancer. After adjustment for age, study area, body mass index, menopausal status, age at menopause for postmenopausal women, parity, use of exogenous female hormones, smoking status and by consumption of green vegetables, beef, pork and green tea, the multivariate HRs (95% CI) of endometrial cancer in women who drank coffee ≤2 days/week, 3-4 days/week, 1-2 cups/day and ≥3 cups/day were 1.00, 0.97 (0.56-1.68), 0.61 (0.39-0.97) and 0.38 (0.16-0.91), respectively (p for trend 5 0.007). In contrast, green tea consumption was not significantly associated with a reduced risk of endometrial cancer (p for trend 5 0.22). The inverse association between coffee consumption and risk of endometrial cancer was consistently observed in subgroup analyses stratified by potential confounders. Coffee consumption may be associated with a decreased risk of endometrial cancer.

Re: A prospective investigation of coffee drinking and endometrial cancer incidence

“…Concordant with previous prospective investigations, they report an overall inverse association for regular coffee consumption 2,3 and also report greater reduction among heavier women than in normal weight women. 3,4 The authors show statistically significant inverse associations for both caffeinated coffee and decaffeinated coffee, with per-cup hazard ratios of 0.90 (0.86-0.95) and 0.93 (0.87-0.99), respectively, and conclude that the observed reduction in endometrial cancer risk does not differ by caffeine content.…”

“…1 Original hazard ratios (95% CI), as presented in article ( Table 2). 2 Assumes <1 cup per day as the referent category and displays relative changes in hazard ratios for each coffee cup category. 3 Assumes 1 cup per day as the referent category and displays relative changes in hazard ratios for each coffee cup category.…”

Epidemiologic Evidence on Coffee and Cancer

“…A hospital-based case control study from Italy, with 454 cases and a 2:1 control to case ratio, found the risk to be half at the upper quintiles of intake as compared to the lowest quintile (30). Two additional studies from Japan were published in 2008; one a population-based cohort of 53,724 women, 117 of which developed endometrial cancer during 15 years of follow-up (31), and the other a case control study with a similar number of cases (32)-both showed relative risks of 0.4 for those consuming 3 or more cups per day of coffee (cohort) or those in the upper tertile of consumption.…”

Inhibitory Effects of Caffeic Acid, a Coffee-Related Organic Acid, on the Propagation of Hepatitis C Virus

“…In addition, several studies (meta-analyses, cohort, and casecontrol) have reported that coffee consumption is inversely associated with liver cancer (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). Furthermore, studies that evaluated the coffee intake of HCC and HCV patients have suggested that a specific substance(s) in coffee could inhibit HCV infection and/or propagation (11,(26)(27)(28).…”