• Posted August 15, 2023

Drinking May Not Raise Risk of Breast Cancer's Return

If you have been diagnosed with breast cancer, you may not have to swear off alcohol completely, a new study suggests.

In it, researchers report that occasional drinking isn't likely to cause a recurrence of breast cancer.

"The findings suggest drinking alcohol is not associated with an increased risk of having a breast cancer recurrence or dying from the disease," said lead study author Marilyn Kwan, a senior research scientist at Kaiser Permanente Northern California Division of Research.

There was no association between alcohol use at the time of a breast cancer diagnosis, or six months later, and the risk of recurrence or death, she said.

"We took into account factors such as age at diagnosis, cancer stage, race and ethnicity, socioeconomic details, menopausal status at diagnosis, the tumor's characteristics, how the cancer was treated, smoking history, physical activity and body mass index at diagnosis, and preexisting health issues that might skew the findings," Kwan said.

The researchers also found that occasional alcohol use (about one-quarter to one-half drink or more per day) among obese patients was actually associated with a lower overall risk of dying, Kwan noted.

"It's not clear how to interpret this finding, although the women with obesity possibly had a healthier lifestyle as they exercised more. We are the first group to make this finding in obese women, and we strongly believe more research is needed to see if the same association is seen in other studies," she said.

Previous studies that have looked at alcohol use and breast cancer have had conflicting results, Kwan said. "Moreover, many were focused on alcohol use before breast cancer. As a result, there are currently no guidelines for breast cancer survivors on alcohol use. Guidelines for preventing cancer risk recommend that women have no more than one alcoholic drink per day," she said.

Kwan noted that these findings, published Aug. 9 in the journal Cancer, should be reassuring to women that drinking a small amount of alcohol won't cause their cancer to return.

"After a cancer diagnosis, many patients are motivated to make lifestyle changes," Kwan said. "That often includes adding exercise to their daily routine and eating a healthier diet. Our study findings suggest that doctors can tell patients that having up to a glass of alcohol a day is not likely to increase their risk of breast cancer recurrence."

For the study, the researchers collected data on more than 3,600 breast cancer survivors who completed a questionnaire about their alcohol use. Over 11 years of follow-up, 524 women saw a recurrence of their cancer, and 834 died -- 369 from breast cancer, 314 from cardiovascular disease and 151 from other health problems.

Dr. Brittney Zimmerman is a breast medical oncologist at Northwell Health Cancer Institute in Huntington and Riverhead, N.Y.

"Cancer guidelines recommend avoiding alcohol or limiting intake to one drink a day," said Zimmerman, who was not involved with the new study.

"I don't know that this article changes how we counsel our patients, but I think that it gives some support that occasional short-term alcohol use is not likely to be associated with poor breast cancer outcomes and is likely safe in small, short quantities," she said.

These findings, however, aren't a license to drink, Zimmerman said. "The guidelines remain the same -- either avoid alcohol or limit it to less than one drink per day."

"I tell my patients that if they want to have a special celebration with a glass of wine it's unlikely that it's going to have a major impact on their outcome," she added.

More information

The American Cancer Society has more on breast cancer.

SOURCES: Marilyn Kwan, PhD, senior research scientist, Kaiser Permanente Northern California Division of Research, Oakland; Brittney Zimmerman, MD, breast medical oncologist, Northwell Health Cancer Institute, Huntington, N.Y. and Riverhead, N.Y.; Cancer, Aug. 9, 2023