SEATTLE - Drinking alcohol, most women know, can increase their risk of getting breast cancer. But now it turns out that moderate drinking before or after diagnosis also appears to increase longevity, researchers from the Fred Hutchinson Cancer Research Center and other centers reported Monday.
The best news for moderate drinking, either pre- or post-diagnosis, was an apparent link between alcohol and better survival from cardiovascular disease, increasingly recognized as a significant risk for breast cancer survivors, researchers said.
And the research found that moderate drinking of up to six drinks a week, either before or after diagnosis, didn't affect a woman's risk of dying from breast cancer.
Polly Newcomb, head of the Cancer Prevention Program at the Fred Hutchinson Cancer Research Center, led the study, published in Monday's edition of the Journal of Clinical Oncology.
Newcomb said many women, aware of what is now a solid connection between drinking alcohol and developing breast cancer, are worried that drinking, either before or after diagnosis, might increase their odds of dying of breast cancer.
Pre-diagnosis drinking - three to six drinks per week - reduced the chance of death from breast cancer 15 percent, compared with nondrinkers diagnosed with breast cancer. Drinking alcohol after diagnosis had no effect either way.
"This is a happy story," Newcomb said. "Our findings should be reassuring to women, because their past experience consuming alcohol or any future consumption will not likely impact their breast cancer survival after diagnosis."
Newcomb and the other researchers relied on data from almost 23,000 women who participated in a National Cancer Institute-sponsored study called the Collaborative Breast Cancer Study, and follow-up studies. Researchers followed the women for about 11 years after diagnosis, on average.
All the women reported on pre-diagnostic alcohol consumption, but only a subsample of 4,881 reported on their drinking post-diagnosis.
Relative to nondrinkers, breast cancer survivors who drank up to nine drinks per week before diagnosis were 25 to 30 percent less likely than nondrinkers to die of heart disease.
Women who drank after diagnosis, even more than 10 drinks per week, had a 40 to 60 percent less chance of dying from cardiovascular disease than nondrinkers, and overall had increased longevity.
"This is a happy story. Our findings should be reassuring to women, because their past experience consuming alcohol or any future consumption will not likely impact their breast cancer survival after diagnosis."
Polly Newcomb, cancer-prevention expert