Smoking and survival in female breast cancer patients

The purpose of this study was to determine if smoking affects survival in female breast cancer patients, both overall and stratified by race, ethnicity, and socioeconomic status. We linked data from the 1996–2007 Florida cancer data system, the Florida Agency for Health Care Administration, and the U.S. census. Inclusion criteria were females ≥18 years, diagnosed with breast cancer, and residing in Florida (n = 127,754). To analyze the association between smoking and survival, we performed sequential multivariate Cox proportional hazard regression models with progressive adjustment for main confounders. Compared to never smokers, worse survival was found in current (hazard ratio 1.33; 95 % CI 1.28–1.38) and former smokers (1.09; 1.06–1.13). Those who smoked <1, 1–2, and >2 packs/day had worse survival (HR 1.28; 1.20–1.36; HR 1.40; 1.33–1.47 and 1.70; 1.45–1.99, respectively) (p for linear trend <0.001), than never smokers. Among Whites, current and former smokers had worse survival (HR 1.38; 1.33–1.44 and HR 1.11; 1.07–1.15, respectively) than never smokers. Worse survival was also found for current and former smokers (HR 1.34; 1.29–1.40 and HR 1.10; 1.06–1.15, respectively) compared with never smokers among non-Hispanics; similarly, worse survival was found among current Hispanic smokers (HR 1.13; 1.01–1.26). The association was not significant for Blacks. Current smoking is associated with worse survival in White breast cancer patients and through all socioeconomic status categories and ethnicities compared to never smoking. Former smoking is associated with worse survival in White and non-Hispanic females. Blacks had similar survival regardless of smoking status. Nonetheless, all female breast cancer patients should be advised to quit smoking.