Comprehensive Assessment of the Impact of Cigarette Smoking on Survival of Clear Cell Kidney Cancer

Purpose: The impact of modifiable environmental factors on kidney cancer specific outcomes is under studied. We evaluated the impact of smoking exposure on cancer specific survival in patients with clear cell renal cell carcinoma treated with surgery. Materials and Methods: From a prospectively maintained database at a single center we collected the characteristics of 1,625 patients with clear cell renal cell carcinoma treated with surgery between 1995 through 2012. We determined the associations of smoking status with advanced disease, defined as AJCC (American Joint Committee on Cancer) stage greater than 2, and with cancer specific survival. Results: The prevalence rate of current, former and never smoking at diagnosis was 16%, 30% and 54%, respectively. Of the patients 62% reported a smoking history of 20 pack-years or greater. Median followup in survivors was 4.5 years (IQR 2.2-7.9). On univariable analysis a smoking history of 20 pack-years or greater was associated with a significantly increased risk of advanced disease (OR 1.43, 95% CI 1.02-2.00). However, it did not achieve an independent association after adjusting for age and gender. Pathological stage and Fuhrman grade adversely affected cancer specific survival on multivariable competing risks analysis. Although the association between smoking and cancer specific survival did not achieve statistical significance on multivariable analysis, the direction of the central estimate (HR 1.5, 95% CI 0.89-2.52) suggested that smoking adversely impacts cancer specific survival. Current smokers faced a higher risk of death from another cause than never smokers (HR 1.93, 95% CI 1.29-2.88). Conclusions: Smoking exposure substantially increases the risk of death from another cause and adversely impacts cancer specific survival in patients with clear cell renal cell carcinoma. Treatment plans to promote smoking cessation are recommended for these patients.