Alcohol and breast cancer risk among Asian-American women in Los Angeles County

We investigated the association between lifetime alcohol intake (including frequency, quantity, duration, timing, and beverage type) and breast cancer in a population-based case-control study of 2,229 Asian Americans diagnosed with incident breast cancer and 2,002 matched control women in Los Angeles County. Additionally, we examined the relation between current alcohol intake and serum concentrations of sex-hormones and growth factors in a subset of postmenopausal control women.Regular lifetime alcohol intake was significantly higher in US-born than non-US-born Asian Americans (P < 0.001) and almost twice as common in Japanese- than in Chinese- and Filipino-Americans (P < 0.001). Breast cancer risk increased with increasing alcohol intake among US-born Asian Americans; the odds ratios (ORs) per 5 grams per day and per 10 years of drinking were 1.21 (95% confidence interval (CI) 1.00 to 1.45) and 1.12 (95% CI, 0.98 to 1.28), respectively. Regular alcohol intake was a significant risk factor for Japanese-, but not for Chinese- and Filipino-Americans. Current consumers compared with nondrinkers showed lower concentrations of insulin-like growth factor binding protein 3 (P = 0.03) and nonsignificantly higher concentrations of estrone and androgens.Regular lifetime alcohol intake is a significant breast cancer risk factor in US-born Asian Americans and Japanese Americans, emphasizing the importance of this modifiable lifestyle factor in traditionally low-risk populations.High consumption of alcohol has been associated consistently with an increased risk of breast cancer in studies conducted primarily among women of European ancestry [1]. The role of alcohol and breast cancer development in Asia and in Asian American women has been less studied, and the results are not consistent [2,3]. Reasons for the inconsistent results in Asians may be related, in part, to the traditionally low alcohol intake in this population, the variable definition of alcohol intake in different