Alcohol Consumption and Breast Cancer Risk According to Hormone Receptor Status in Japanese Women: A Case-Control Study

Abstract

Alcohol consumption is a risk factor for breast cancer in Western countries, but few studies have evaluated the risk for Japanese women, who have a relatively low alcohol intake. This case-control study investigated the association of alcohol consumption with breast cancer risk according to estrogen-receptor and progesterone-receptor (ER/PgR) status in Japanese women. From female patients aged 30 years and over admitted to a single hospital in Japan between 1997 and 2011, 1,256 breast cancer cases (669 ER+/ PgR+, 162 ER+/PgR−, 21 ER−/PgR+, 305 ER−/PgR−, and 99 missing) and 2,933 controls were selected. Alcohol-related measures were assessed using a self-administered questionnaire. Unconditional logistic regression analysis was performed. Alcohol-related measures were not associated with breast cancer risk among the women overall. Moreover, no association was observed between ever drinking and the risk of a concordant receptor subtype (ER+/PgR+ or ER−/PgR−). Conversely, ever drinking was inversely associated with the risk of discordant subtype (ER+/PgR−, odds ratio (OR) = 0.63, 95% confidence interval (CI): 0.41-0.95; ER−/PgR+, OR = 0.44, 95% CI: 0.14-1.42). For ER+/PgR−, an inverse association with the amount of alcohol consumed per day was observed (P for trend = 0.04), and this inverse association was limited to premenopausal women. Alcohol consumption may have differential effects on concordant and discordant receptor subtypes of breast cancer. In view of the low frequency of discordant subtype in Japanese women and their relatively low alcohol intake, our findings may provide a clue for elucidating the etiology of breast cancer rather than for preventing discordant subtype.

Alcohol consumption and survival after breast cancer diagnosis in Japanese women: A prospective patient cohort study

“…The exposure variables related to alcohol consumption included history of alcohol drinking (never, ever, past, current), frequency of drinking per week (never, occasional or 1–2 times, 3–7 times), age at start of drinking (never, ≤20 years, ≥21 years), and amount of alcohol consumed per day (never, <5.0 g, ≥5.0 g). Although, in our previous case-control and cohort studies of breast cancer, the quantitative exposure variable had been classified based on finer categories [28, 29], the present study used the mid-point for variable categorization because of the limited number of patients. If necessary, analysis based on the finer categories was also performed.…”

Breast Cancer in Adolescent and Young Adult Women Under the Age of 40 Years

“…[10][11][12][13] Associations between alcohol intake and breast cancer risk are also less clear among AYAs than in postmenopausal women. [14][15][16] Exercise and a plant-based diet are potentially protective against breast cancer among AYAs, as they are in older populations, although these studies are small. [17][18][19][20]…”

Exposure to radiofrequency radiation increases the risk of breast cancer: A systematic review and meta‑analysis

“…Breast cancer is one of the most commonly diagnosed cancers affecting women in Taiwan, and its incidence rate is gradually increasing worldwide (7). The known risk factors for breast cancer are obesity (8), smoking (9), genetic mutations such as breast cancer susceptibility gene 1 (BRCA1) and breast cancer susceptibility gene2 (BRCA2) which are tumor suppressor genes (9,10), family history (11,12), alcohol consumption (11)(12)(13)(14), exposure to estrogen hormones over an extended period (11,14), diethylstilbestrol and postmenopausal hormone therapy (15,16). In addition, previous studies suggested that breast cancer can be attributed to exposure to radiofrequency radiation (17,18).…”