Although alcohol use increases the risk of developing breast cancer, a new Kaiser Permanente study found that, in general, consuming alcohol within six months of a breast cancer diagnosis was not associated with an increased risk of breast cancer recurrence or death from the disease.

It’s been established that the more alcohol a person drinks, the higher their risk of developing cancer may be. Drinking even small amounts of alcohol is linked with an increased risk of breast cancer in women, according to the American Cancer Society. This is because alcohol use is known to raise a woman’s levels of estrogen and acetaldehyde, raising breast cancer risk.

“We know that women who drink alcohol are at increased risk of developing breast cancer and that the risk increases as alcohol use increases,” said lead author Marilyn Kwan, PhD, a research scientist with the Kaiser Permanente Northern California Division of Research, in a Kaiser news release. “For this reason, we thought that drinking alcohol after a breast cancer diagnosis could increase the risk of a cancer recurrence. But our study found that, overall, drinking alcohol after a breast cancer diagnosis does not impact a patient’s prognosis.”

Published in Cancer, the prospective study is among the largest to look at short-term alcohol use after breast cancer. Researchers utilized data from the Pathways Study, a large U.S. study that follows about 4,500 breast cancer survivors to examine the correlation between lifestyle changes and outcomes.

“After a breast cancer diagnosis, patients are often focused on making lifestyle changes that could help them live longer,” said senior author Lawrence Kushi, ScD, a research scientist at the Kaiser Permanente Northern California Division of Research. “The aim of our study is to provide breast cancer survivors and their physicians with information that can help them make decisions that will improve both their quantity and quality of life.”

The Kaiser Permanente study included 3,659 women who, upon entering the Pathways Study, completed a questionnaire about their alcohol use prior to their breast cancer diagnosis. They were given same questionnaire six months after their diagnosis. After being tracked for the following 11 years, 524 women had a breast cancer recurrence, and 834 died—369 of breast cancer, 314 of cardiovascular disease and 151 of other causes.

In general, no association was found between alcohol use at the time of breast cancer diagnosis or six months later and the risk of recurrence or death.

In a puzzling finding, the researchers noted that women with obesity when diagnosed with breast cancer who occasionally drank alcohol saw a decreased risk of overall death compared with women who did not drink, due to fewer deaths from cardiovascular disease.

Researchers hope the study findings will help doctors accurately inform and guide breast cancer survivors on how to adopt healthy lifestyle changes that can improve their outcomes.