The impact of smoking cessation on breast cancer patients’ survival.

Abstract

1542 Background: Breast cancer remains to be one of the highest causes of cancer mortality amongst females globally, second only to lung cancer. Smoking is strongly associated with increased all-cause mortality, including breast cancer related death. It has also been shown to have a negative influence on long-term survival after successful breast cancer treatment. Prior studies have shown that smoking cessation may lead to improved prognosis and better outcomes. Methods: This is a retrospective cohort study of breast cancer patients who were identified as smokers, some of who were referred to the tobacco treatment program (TTP) located at MD Anderson Cancer Center. TTP includes careful patient screening, motivational counseling, and pharmacotherapy. We complemented the original data collected by conducting in-depth chart reviews to extract data including patient demographics, date of diagnosis, stage of cancer, smoking status, duration of abstinence and dates of follow-up or death. We then examined associations between smoking status and survival status using multinomial regression models adjusting for biomarkers of disease and personal characteristics. Results: Among all breast cancer patients (N = 31069), we identified those who are smokers (n = 2320) by matching the TTP database with smoking status from our institutional electronic health records. Of those, 740 patients were referred to TTP. Amongst these, 242 patients quit smoking and remained abstinent at the 9 month follow-up. Compared with non-abstainers, those who quit were more likely to be alive with no evidence of disease during the observation time (RR = 1.62, p = 0.045). When analyzed at different stages, the RR went from 1.35 (p = 0.42) to 2.77 (p = 0.34) for stages 3 and 1, respectively. Although the strength of this relationship varied among disease stage, the direction of the relationship remain consistent. Conclusions: Our data shows that smoking cessation is associated with improved survival status amongst breast cancer survivors across all stages. Comprehensive smoking cessation services may improve survivorship when started as early as the time of diagnosis. Further analysis of the association between smoking cessation and other associated medical outcomes will be conducted to further determine the specific impact of cessation programs.