Being diagnosed with breast cancer is an enormous life-changing event, but it isn’t the certain death sentence it once was just a few decades ago. Breast cancer now has a greater than 90 percent five-year survival rate in the United States, resulting in a large and ever-growing number of survivors. That’s the good news.
The bad news is breast cancer survivors are at two-to-six times greater risk of developing a second cancer compared to women in the general population, so it is important to understand factors that may increase that risk.
A new study by researchers at Fred Hutchinson Cancer Research Center, published online Sept. 8, 2009, in the Journal of Clinical Oncology found that obesity, alcohol use and smoking all significantly increase the risk of a second breast cancer diagnosis among breast cancer survivors.
“Our study results gives valuable information about lifestyle choices for breast cancer survivors to potentially reduce their risk of second cancers: Stay at a normal weight; don’t smoke; and drink in moderation,” said Christopher I. Li M.D., Ph.D., an associate member of the Public Health Sciences Division at the Hutchinson Center and the study's lead author.
Li is an epidemiologist who primarily studies what causes breast cancer and how it can be prevented. He and his team found that obese women had a 50 percent increased risk, women who consumed at least one alcoholic drink per day had a 90 percent increased risk, and women who were current smokers had a 120 percent increased risk of developing a second breast cancer compared to women in the general population.
His study, funded by the National Cancer Institute, adds to a small, but growing body of evidence that obesity (a body mass index of 30 kg/m2 or more), alcohol consumption — consuming at least seven drinks a week — and current smoking may be important risk factors for second breast tumors. The research also suggests that current smokers who consume at least seven drinks a week may be at “particularly high risk” of second breast cancer.