SAN FRANCISCO — Women who drank more than 2.5 cups of coffee daily had a significantly lower risk of endometrial cancer, compared with women who didn't drink coffee, according to a study of more than 20,000 postmenopausal women.
Previous studies have shown that coffee has an inverse association with endometrial cancer risk, said Dr. Stefano Uccella of the Mayo Clinic in Rochester, Minn.
In a poster presented at the annual meeting of the Society of Gynecologic Oncologists, Dr. Uccella and his colleagues reviewed the impact of coffee and other sources of caffeine on endometrial cancer risk among participants in the Iowa Women's Health Study, a large, prospective cohort investigation of postmenopausal women that has been ongoing since 1986.
The study population included 23,356 women, 5,218 of whom met criteria for obesity.
The women completed a 126-item food frequency questionnaire at enrollment.
The researchers identified 471 cases of endometrial cancer through 2005, using information from the Iowa SEER (Surveillance Epidemiology and End Results) cancer registry.
Overall, women who consumed more than 2.5 cups of coffee daily were significantly less likely to develop endometrial cancer, compared with women who drank no coffee (odds ratio, 0.65), after investigators controlled for variables including smoking, diabetes, hypertension, estrogen use, reproductive history, body mass index, body fat distribution, alcohol use, and caloric intake.
Overall caffeine intake greater than 385 mg/day also was significantly associated with a reduced risk of endometrial cancer, compared with a daily caffeine intake of less than 30 mg (OR, 0.80).
However, no significant associations were found between endometrial cancer risk and the consumption of tea, regular or diet cola, chocolate candy, or chocolate baked goods.
“The association appeared to be related to coffee per se, and not other sources of caffeine,” the researchers noted.
When the results were separated by BMI, the association between coffee and a reduced risk of endometrial cancer remained significant in the subset of obese women (BMI 30 kg/m
The significance of the association between coffee consumption and the risk of endometrial cancer was somewhat attenuated in women with a BMI less than 30 (OR, 0.77).
The results support findings from previous studies, and suggest that more research is needed to assess coffee's potential protective effect against endometrial cancer, the researchers wrote.
Disclosures: None was reported.
In the study, consuming more than 2.5 cups of coffee daily significantly lowered endometrial cancer risk.