Mean age at diagnosis of breast cancer was 58 years, and nearly all of the participants were white. Half of the women had smoked, and 20% reported actively smoking 1 year before breast cancer diagnosis. Recent smokers were “generally younger, less educated, leaner, more likely to be heavy drinkers (≥ 10 drinks per week), and less likely to have undergone mammography screening than former or never smokers,” they wrote.
The study found that, when compared with never smokers, women who quit smoking before their breast cancer diagnosis were typically postmenopausal and more likely to have used hormone therapy, consumed alcohol, and undergone mammography. The team saw almost identical distributions of localized and regional-stage disease at diagnosis among never, former, and recent smokers.
When asked if any of the findings surprised him, Dr Passarelli told Cancer Therapy Advisor, “Unfortunately, no. It is unusual to see associations with an HR as strong as 14 in an epidemiologic study. But smoking is such a strong risk factor for lung cancer and mortality that these large estimates of association are expected.”
He noted that in his team’s observational study, there were factors highly correlated with smoking behaviors that they could not adequately control for in statistical analyses, and that these factors could be driving some of the associations they observed.
In regard to smoking cessation programs, Dr Passarelli recommended the American Society of Clinical Oncology’s tobacco cessation guide, which provides oncology health care providers with talking points about cessation strategies and tips on framing conversations about quitting smoking after cancer (http://www.asco.org/sites/default/files/tobacco_cessation_guide.pdf).
- Passarelli MN, Newcomb PA, Hampton JM, et al. Cigarette smoking before and after breast cancer diagnosis: mortality from breast cancer and smoking-related diseases [published online ahead of print January 25, 2016]. J Clin Oncol. doi: 10.1200/JCO.2015.63.9328.