Body mass and smoking are modifiable risk factors for recurrent bladder cancer
Menée aux Etats-Unis auprès de 726 patients atteints d'un cancer de la vessie, cette étude évalue l'association entre l'indice de masse corporelle, le tabagisme et le risque de récidive du cancer
BACKGROUND In the Western world, bladder cancer is the fourth most common cancer in men and the eighth most common in women. Recurrences frequently occur, and continued surveillance is necessary to identify and treat recurrent tumors. Efforts to identify risk factors that are potentially modifiable to reduce the rate of recurrence are needed. METHODS Cigarette smoking behavior and body mass index were investigated at diagnosis for associations with bladder cancer recurrence in a population-based study of 726 patients with bladder cancer in New Hampshire, United States. Patients diagnosed with non–muscle invasive urothelial cell carcinoma were followed to ascertain long-term prognosis. Analysis of time to recurrence was performed using multivariate Cox regression models. RESULTS Smokers experienced shorter time to recurrence (continuing smoker hazard ratio [HR] = 1.51, 95% confidence interval [CI] = 1.08-2.13). Although being overweight (body mass index > 24.9 kg/m2) at diagnosis was not a strong independent factor (HR = 1.33, 95% CI = 0.94-1.89), among continuing smokers, being overweight more than doubled the risk of recurrence compared to smokers of normal weight (HR = 2.67, 95% CI = 1.14-6.28). CONCLUSIONS These observational results suggest that adiposity is a risk factor for bladder cancer recurrence, particularly among tobacco users. Future intervention studies are warranted to evaluate whether both smoking cessation and weight reduction strategies reduce bladder tumor recurrences. Cancer 2013. © 2013 American Cancer Society.