LAUSR

Background: Smoking is associated with an increased incidence of hormone receptor positive breast cancer. Data regarding worse breast cancer outcome in smokers are accumulating. Current literature regarding the impact of smoking on breast cancer characteristics is limited. The aim of this study was to evaluate the impact of smoking on the characteristics and outcome of estrogen receptor positive, human epidermal growth factor receptor 2 (HER2) negative early breast cancer. Methods: This was a retrospective single center study. All patients diagnosed from 4/2005 through 3/2012 and treated in our institute for early, estrogen receptor positive, HER2 negative breast cancer, whose tumors were sent for Oncotype DX analysis were included. Medical records were reviewed for demographics, clinico-pathological parameters, treatment and outcome. Patients were grouped and compared according to smoking history (present or past smokers vs. never smokers) and status (current vs. former and never smokers). Heavy smokers (pack years ≥30) were analyzed separately. Results: A total of 671 patients were included. 28.7% had a history of smoking, 17% were current smokers and 11.5% were heavy smokers. Smoking had no impact on tumor size, nodal involvement and Oncotype DX recurrence score. Angiolymphatic and perineural invasion rates were higher in current smokers than in the rest of the cohort (11% vs. 5.1%, p=0.023, 9% vs. 3.45%, p=0.013, respectively). Smoking had no other impact regarding histological characteristics. Five-year disease free survival and overall survival rates were 95.7% and 98.5%, respectively. Smoking had no impact on outcome. Conclusions: In patients with estrogen receptor positive, HER2 negative, early breast cancer, smoking had no clinically significant influence on tumor characteristics and outcome. As the study was limited to a specific subgroup of the breast cancer population in this heterogeneous disease and since smoking is a modifiable risk factor for the disease, further research is required to clarify the possible impact of smoking on breast cancer. Citation Format: Goldvaser H, Gal O, Rizel S, Hendler D, Neiman V, Shochat T, Sulkes A, Brenner B, Yerushalmi R. The association between smoking and breast cancer characteristics and outcome [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-08-25.