Monday, September 30, 2013

Breast Cancer Awareness Month: Decipher mixed messages about alcohol and breast cancer

Research reported June 2013 in the Journal of Clinical Oncology (JCO) finds alcohol does not reduce survivability from breast cancer. The study is encouraging Breast Cancer Awareness Month news for women who prefer to drink, but the encouragement fades quickly because there remains a higher cancer risk associated with drinking.

Previous research has linked alcohol consumption to an increased risk of developing breast cancer, and the JCO study does not contradict those findings. (See the Oct. 2012 examiner article on the breast cancer/alcohol link) Alcohol consumption is believed to influence breast cancer risk through increases in estrogen production and also by altering breast tissue in developmental years. An August 28 Journal of the National Cancer Institute report showed a double-digit increase in breast cancer risk for women who drank as little as one drink daily between the first menstruation and the first pregnancy. The results were independent of drinking after first pregnancy.

"The risk increased by 11 percent for every 10 grams a day of intake, about six drinks per week," said study author Ying Liu, M.D., of Washington University School of Medicine in St. Louis. A drink, or 10 grams of alcohol, is a 12 oz. beer, a 4 oz. glass of wine or a1.5 oz. shot of hard liquor.

Liu's team also discovered an increase in benign breast disease, a non-cancerous condition which accounts for 80 percent of breast lumps. These benign lumps do increase the risk of breast cancer by 500 percent. The more alcohol consumed between the onset of the first menstrual period and the first pregnancy, the greater the risk for both benign breast disease and breast cancer, the study reported.

The results are a warning in favor of alcohol moderation – or abstinence – during adolescence and early adulthood when the breasts are developing new tissue. "Breast tissues are particularly susceptible to environmental exposures between [the onset of menstruation] and first pregnancy because they undergo rapid cellular proliferation," Liu said. "Our results suggest that alcohol intake before the first pregnancy consistently increases the risk.” The association between drinking before first pregnancy and breast cancer appeared to be stronger for women who had a greater interval of time between the first menstrual cycle and first pregnancy, which is to say that older first-time moms carry a higher risk if they were daily drinkers. (See full article.)

The JCO study by Seattle's Fred Hutchinson Cancer Research Center indicates that once a patient has the disease, drinking before and after her diagnosis does not impact survival from the disease. In fact, some benefit was found in women who were “moderate” drinkers due to a reduced risk of dying from cardiovascular disease, a major cause of mortality among breast cancer survivors.

So alcohol can increase breast cancer risk, but may also improve outcomes once a patient has the disease.

Polly Newcomb, Ph.D.,led the study. "Our findings should be reassuring to women who already have breast cancer because their past experience consuming alcohol will not impact their survival after diagnosis."

The study began in 1988 and was conducted in New Hampshire, Massachusetts and Wisconsin. Among study participants with a history of breast cancer, the authors found that the amount and type of alcohol a woman reported consuming in the years before her diagnosis was not associated with her likelihood from dying from the cancer. However, the authors also found that those who consumed a moderate level of alcohol (three to six drinks per week) in the years before their cancer diagnosis were 15 percent less likely to die from cardiovascular disease than non-drinkers.

The JCO report does not recommend drinking alcohol. An accompanying editorial cites many other risks of drinking alcohol, including alcohol use disorders (alcohol abuse and the disease of alcoholism), and that “alcohol intake may be associated with accidental or violent death.” A separate report Feb. 14 from the U.S. Centers for Disease Control and Prevention (CDC) demonstrated other health risks specific to women drinkers, beyond increasing the chance for breast cancer, leading to 23,000 deaths annually.

Additionally, the American Journal of Public Health posted research from Boston University earlier this year on the connection between all cancers and alcohol consumption. (See related examiner story) That study determined that alcohol-related cancer death took away an average of 18 potential years from a person's life. Boston University's Timothy Naimi, Ph.D., said. “When it comes to cancer, there is no safe level of alcohol consumption."
--from my Oct. 1 news article (full report)