As few as three alcoholic drinks per week (including red wine) have been shown to increase breast cancer risk. The increased risk conferred by drinking can begin as early as the teenage years. Now a new study has reported that binge drinking in young women is linked to increased risk of early-onset luminal A breast cancer.
Alcohol's effect on breast cancer
Alcohol consumption is associated with increased risk of breast cancer and its recurrence. The risk appears to be highest for hormone receptor positive (ER+/PR+) disease and lobular breast cancer.
Alcohol consumption can have varying effects on breast cancer risk depending on the pattern of consumption even when the total consumed is held constant. In other words, having multiple drinks in one day increases breast cancer risk more than having the same number of drinks spaced over a week. Women who are fast metabolizers of alcohol (and therefore "can't hold their liquor") have a higher risk of breast cancer from alcohol consumption than slow metabolizers. Alcohol appears to preferentially increase breast cancer risk among women already at high risk for the disease. Alcohol also appears to heighten the risk associated with using hormone replacement therapy (HRT).
In addition to being a risk factor for the development of breast cancer, high alcohol intake before diagnosis appears to have an unfavorable effect on the course of the disease. While a modest amount of alcohol does not appear to increase risk of recurrence, consuming three to four alcoholic drinks per week has been reported to increase it, especially for postmenopausal and overweight women. Consuming alcohol has been shown to interfere with the effectiveness of treatment with tamoxifen.
Latest research finds binge drinking can lead to early BC
The study referenced above was designed to investigate whether binge drinking trends are linked to rates of female breast cancer diagnosed under age 40. To conduct the study, the authors used data from the Surveillance, Epidemiology, and End Results (SEER) Cancer Registry. Binge drinking was defined as four or more drinks on a single occasion.
Moderate drinking (≥ 1 drinks/day) and heavy drinking (≥ 2 drinks/day) each were found to be associated with modest increases in the risk of luminal A breast cancer, but not other breast cancer subtypes. Luminal A breast cancer is defined as strongly estrogen and progesterone receptor positive (ER+/PR+) and not HER2 overexpressing (HER2-), with low tumor grade and low proliferation (Ki-67 < 15%). Luminal B breast cancer is weakly to moderately ER+ and PR+ and can be HER2 overexpressing (HER2+). It may have low tumor grade, but with higher proliferation and DNA instability than luminal A. Mixed hormone receptor (ER+/PR- or ER-/PR+) tumors usually are luminal B.
Binge drinking was found to be associated with modestly increased risk of early-onset (below age 40) luminal A breast cancer. The analysis also suggested that binge drinking was associated with early-onset luminal B breast cancer. The authors conclude that their findings suggest that one reason for the recent increase in early-onset breast cancer is increased alcohol consumption, including binge drinking.