Avoiding alcohol in adolescence may reduce breast cancer risk

Drinking alcohol during adolescence has been linked to an increased risk of breast cancer, especially for girls with a family history of the disease, a study says.

Researchers examined data on 6,888 females who were 9 to 15 years old in 1996 and participated in the Growing Up Today Study, which followed more than 9,000 females from adolescence to adulthood. They found that girls who had a family history of breast cancer doubled their risk for developing benign breast disease -- often an indicator of future breast cancer -- if they drank at least seven alcoholic drinks a week during adolescence.

"Women with breast cancer may want to make their daughters aware that they may decrease their own chances of getting breast cancer by avoiding alcohol while in their teens," said Catherine Berkey, ScD, a biostatistician at Harvard Medical School and lead author of the study published online Nov. 14 in Cancer, the journal of the American Cancer Society (link).

Benign breast disease refers to a range of conditions that can cause painful or lumpy breasts. The study looked at several potential risk factors for the disease, including height, weight, body mass index, age of first menstrual period and alcohol consumption. Of those participating in the study, 147 females had been diagnosed with benign breast disease as adults and 6,741 had not.

Those with a mother or aunt who had breast cancer were twice as likely to develop benign breast disease as those with no family history of the cancer, the study said.

Researchers also found different risk factors for girls with a family history of breast cancer versus those with no family history. For example, factors such as body mass index and waist circumference during adolescence were tied to an increased chance of developing benign breast disease for women with no family history of breast cancer, but not for those with a family history of the cancer. Berkey said further research is needed to understand those connections.

Previous research shows that if a woman is diagnosed with breast cancer before age 40, her daughter is twice as likely to get the cancer. Berkey, who has been involved in breast cancer research for more than 12 years, said this latest study was conducted to try to identify ways to help prevent breast cancer from developing in those considered most at risk.

"I personally expected alcohol to increase risk among those with no family history and to have no [or smaller] association among those with a family history," she said in an email. "So I was surprised to see alcohol affects strongest among young females with a family history."