Smoking and Risk of Breast Cancer
The carcinogenic potential of tobacco smoke is unarguable, which has led researchers to investigate plausible biologic reasons for how smoking affects breast cancer risk. A study published in Breast Cancer Research by Michael E. Jones, BA, MA, PhD, of the Division of Genetics and Epidemiology, Institute of Cancer Research, London, and colleagues suggests smoking may be associated with an increased risk of breast cancer, particularly among those who began smoking during adolescence and those with a family history of the disease.
The Generations Study, one of the world’s largest prospective cohort studies dealing with breast cancer, included 102,927 women from the United Kingdom (recruited from 2003 to 2013 and followed for an average of 7 years). They examined the risk of invasive breast cancer in relation to smoking.
Of this study population, 1815 of the women went on to develop breast cancer. The researchers found a significant variation in the risk of breast cancer by the age at starting smoking, with an increase in breast cancer risk if smoking started before the age of 17 or continued for more than 10 years.
The study concluded that female smokers with a family history of breast cancer are 35% more likely to develop the disease than someone with a family history who had never smoked. In regard to those without a family history of breast cancer, women who had ever smoked were about 14% more likely to develop breast cancer than never smokers.