Influence of body mass index and smoking on the long-term survival of patients with renal cell cancer.

Background: Smoking and obesity are known risk factors for renal cell carcinoma (RCC). We determined the influence of smoking, body mass index (BMI), and symptoms on the survival of patients with RCC.

Patients And Methods: In this retrospective study, the relative overall survival (OS) up to 25 years was calculated among 948 Finnish patients with RCC diagnosed between 1964 and 1997 using a Bayesian univariate analysis and the life-table method.

Results: Obese patients had better OS than did normal or underweight patients (median, 5.9 years, 3.4 years, and 12 months, respectively), with lower stage and more asymptomatic tumors at diagnosis and fewer relapses during surveillance. Clinical presentation of the tumor was a stronger prognostic factor than BMI; however, asymptomatic patients with a low BMI had poorer survival compared with normal or overweight patients. There was no difference in tumor stage or presentation at diagnosis between the nonsmokers and smokers; however, the smokers had more relapses with shorter disease-free intervals (DFIs) than did the nonsmokers. The OS was poorer in the smokers (4.2 years compared with 6.6 years in nonsmokers), but no difference was observed in cancer-specific survival (CSS).

Conclusion: Overweight patients have better survival, with more asymptomatic or local tumors. The clinical presentation was a stronger prognostic factor than BMI. Additionally, survival is poorer in smokers, even if there is no difference in tumor stage or symptoms.