Even a little drinking may raise breast cancer risk: study

Just one alcoholic drink a day can boost a woman's risk of breast cancer by about 5 percent, according to a new review of existing research.

Heavier drinking - three or more drinks a day - can increase risk up to 50 percent, according to researchers from Germany, France and Italy.

"Alcohol consumption is causally related with breast cancer," the study authors concluded after reviewing 113 prior studies. They attributed 2 percent of breast cancer cases in Europe and North America to light drinking alone, and about 50,000 cases worldwide to heavy drinking.

The research seems to confirm the expert advice for women to minimize drinking, said study leader Dr. Helmut Seitz, professor of medicine, gastroenterology and alcohol research at the University of Heidelberg in Germany.

The findings suggest that healthy women at average risk of breast cancer should not consume more than one alcoholic drink a day, the authors said.

"Women at an elevated risk for breast cancer should avoid alcohol or consume alcohol only occasionally," the researchers wrote. Those at increased risk include those with a family history of breast cancer.

The link between alcohol and breast cancer was first suggested in the early 1980s, the authors said. To update the research, they searched for studies published before November 2011. They found more than 3,400 studies in all and narrowed their focus to 113 that examined the effects of light drinking on breast cancer risk.

New Cases: An estimated 207,090 new cases of invasive breast cancer are expected to occur among women in the US during 2010; about 1,970 new cases are expected in men. Excluding cancers of the skin, breast cancer is the most frequently diagnosed cancer in women. After increasing from 1994 to 1999, female breast cancer incidence rates decreased from 1999 to 2006 by 2.0% per year. This decrease may reflect reductions in the use of menopausal hormone therapy (MHT), previously known as hormone replacement therapy, following the publication of results from the Women's Health Initiative in 2002, which linked combined estrogen plus progestin MHT use to increased risk of coronary heart disease and breast cancer. It might also reflect a slight drop in mammography utilization during that time period, which could delay the diagnosis of some tumors.

According to the National Health Interview Survey, mammography rates in women 40 and older decreased from 70.1% in 2000 to 66.4% in 2005.

In addition to invasive breast cancer, 54,010 new cases of in situ breast cancer are expected to occur among women in 2010.

Of these, approximately 85% will be ductal carcinoma in situ (DCIS). Since 1998, in situ breast cancer incidence rates have been stable in white women and increasing in African American women.

: An estimated 40,230 breast cancer deaths (39,840 women, 390 men) are expected in 2010. Breast cancer ranks second as a cause of cancer death in women (after lung cancer).