A large study of breast cancer survivors has found that those who quit smoking after their diagnosis had a 33 percent lower risk of death as a result of breast cancer than those who continued to smoke.
The study involved more than 20,600 women with breast cancer, and is one of the largest studies of survival outcomes according to smoking habits in women with a history of breast cancer, and the first study to assess smoking habits both before and after diagnosis.
Full reference: Passarelli, M. et al. Cigarette Smoking Before and After Breast Cancer Diagnosis: Mortality From Breast Cancer and Smoking-Related Diseases. Journal of Clinical Oncology, 2016