THURSDAY, Nov. 11 (HealthDay News) -- Among women with breast cancer, being a current smoker or having a history of smoking is associated with an increased risk of breast cancer death or death from other causes, according to research presented at the American Association for Cancer Research's Frontiers in Cancer Prevention Research Conference, held from Nov. 7 to 10 in Philadelphia.
Dejana Braithwaite, Ph.D., of the University of California in San Francisco, and colleagues studied a cohort of 2,265 women of multiple ethnicities diagnosed with breast cancer during 1997 to 2000. The researchers followed the cohort for a median nine years and analyzed associations between smoking history and breast cancer death, non-breast cancer-related death, and all-cause death, adjusted for baseline age, body mass index, education, tumor characteristics, and adjuvant treatment.
During the follow-up, there were 164 breast cancer deaths and 120 non-breast cancer deaths recorded. Compared to women who had never smoked, the researchers found that women who were current or past smokers had a 39 percent higher risk of dying from breast cancer and a two-fold higher risk of dying from a non-breast cancer cause (hazard ratio [HR], 2.16). In subgroup analysis, the detrimental effect of smoking on survival was greatest among women with a body mass index less than 25 kg/m² (HR, 1.83), human epidermal growth factor receptor 2-negative tumors (HR, 1.61), and those who were postmenopausal (HR, 1.47).
"The implication of this research is that it is important for physicians to improve smoking cessation efforts, especially among women newly diagnosed with breast cancer, in order to improve breast cancer-specific outcomes and overall health outcomes," Braithwaite said in a statement.