Women Smokers are at Increased Risk of Common Type of Breast Cancer

Young women who smoke at least one pack of cigarettes every day for 10 years or more are 60 percent morelikely to get breast cancer, according to new findings.

 Dr Christopher Li and his colleagues from Fred Hutchinson Cancer Research Center, Seattle analyzed data from young women diagnosed with breast cancer between the years 2004 and 2010. It involved 778 women with estrogen-receptor positive breast cancer -the most common type of cancer and 182 women who had the less common but more aggressive triple-negative type. To make comparisons, 938 women without cancer also were a part of the research.

 The participants who had ever smoked were 30 percent more likely to develop any kind of cancer compared to those who never smoke. The study did not show any direct link between smoking and triple-negative breast cancer. But, current smokers and those who had smoked more than a decade, had 50 percent increased risk of getting estrogen receptor-positive breast cancer compared to light smokers. The women who had smoked nearly one pack each day since a decade weret 60 percent more likely to get the less common cancer form.

 While previous studies have helped link smoking and breast cancer but, research from cases involving younger women have given conflicting results.

Li said, "I think there is a growing appreciation that breast cancer is not just one disease and there are many different subtypes. In this study, we were able to look at the different molecular subtypes and how smoking affects them." reports Reuters.

"There are so many different chemicals in cigarette smoke that can have so many kinds of effects." added Li.

The researchers believe that substances found in cigarettes act like estrogen, which induces the estrogen- receptor positive cancer. The growth of the cancer cells is triggered by the hormone estrogen. Breast cancer is the most common type of cancer among women around the globe.  According to the National Cancer Institute, there were nearly 39,620 deaths and 23,234 new cases last year in the U.S. The highest mortality due to breast cancer is experienced by African American women compared to other racial and ethnic groups.

"The health hazards associated with smoking are numerous and well known. This study adds to our knowledge in suggesting that with respect to breast cancer, smoking may increase the risk of the most common molecular subtype of breast cancer but not influence risk of one of the rarer, more aggressive subtypes," Dr. Li mentioned in a press statement.