Women smokers over 50 at increased risk of breast cancer

Mar 3 2011

Compared to women who had never smoked, breast cancer risk increased by nine percent among former smokers and by 16 percent among current smokers according to research by Karen Margolis, MD, a senior clinical investigator with the HealthPartners Research Foundation and her collaborators in a study that was published today in the British Medical Journal.

“This study pinpoints one more thing women can do to reduce their risk for breast cancer”

Dr. Margolis and collaborators analyzed data for almost 80,000 women between ages 50 and 79. In total, 3,250 cases of invasive breast cancer were identified by the researchers during an average of ten years of follow-up.

The research team found that the highest risk was among current smokers with the highest intensity and duration of smoking, and among women who began smoking during the teenage years or before their first full-term pregnancy. Among former smokers, the increased risk of breast cancer persisted for up to 20 years following smoking cessation.

The team also studied the effects of passive or second hand smoke and found that extensive exposure to second-hand smoke leads to an increased risk, though further research is needed.

"This study pinpoints one more thing women can do to reduce their risk for breast cancer," Dr. Margolis says. "There are a lot of risk factors beyond our control, but this is a lifestyle change women can make that will have an impact."

Dr. Margolis says this study highlights the need for interventions to prevent people from initiating smoking, especially at an early age, and to encourage quitting at all ages.