Smoking is known to increase the risk of 14 different types of cancer and is responsible for 30% of cancer deaths according to the American Cancer Society. Breast cancer looks set to become the 15th type to be added to the list after a major study published this week in Breast Cancer Research showed that smoking increases a woman’s risk of developing breast cancer by up to 35%.
The Generations Study collected data from the women for an average of 7 years by sending them questionnaires about their smoking history, alcohol intake and other lifestyle choices to find out more about the causes of breast cancer. The study conducted by researchers from the Institute for Cancer Research in London, UK analyzed data from 1,815 of the participants who developed invasive breast cancer, allowing a comparison between women who smoked or had ever smoked and those who had never smoked.
The researchers found that the risk of developing breast cancer was greatest in individuals who began smoking before they started menstruating or had close family members with breast cancer. Strikingly, they also found that the increased risk can persist for at least two decades after giving up smoking, although this does decline over time.
Often percentage increases in risk of developing cancer types do not translate into much actual risk. For example, a 100% increase in lifetime risk of developing a rare cancer which affects just 1 in 10,000 people is still only a fairly low risk of 2 in 10,000. However, with breast cancer affecting 1 in 8 women, and a quarter of a million women in the USA being diagnosed every year, these research findings should be of concern to the estimated 20 million adult women in the USA who smoke.
After decades of well publicised health warnings, whether this new evidence will provide added incentive for women to give up smoking is debatable. However, especially for women with a family history of breast cancer, this research should be additional food for thought regarding their future health.