Self-report of smoking, obesity and hypertension history and survival among a cohort of iowa renal cell carcinoma cases

PURPOSE: Smoking, obesity and hypertension are well-established risk factors for the development of renal cell carcinoma (RCC). However, little is known regarding the ability of RCC patient history regarding these characteristics to predict future survival. METHODS: To evaluate this question, we conducted follow-up on a cohort of incident RCC cases first assembled in Iowa from 1986–1989 for case-control analysis. We report data on 364 cases aged 40–86 years who reported detailed anthropometric and lifestyle history on a mailed questionnaire. Mortality experiences through 1998 were determined by linkage to the Iowa Cancer Registry and other databases; 233 deaths were identified during the 2,470 total years of follow-up, with 145 of those having RCC listed as the underlying cause of death on the death certificate. The Cox Proportional Hazards model was used to estimate the risk associated with each potential prognostic characteristic. RESULTS: After adjustment for age, a suggestion of an association with survival was noted for history of hypertension [Relative Risk (RR) = 0.8; 95% Confidence Interval (CI) 0.5–1.1] but no association was noted for either smoking or weight history. After further adjustment for tumor stage at diagnosis, evidence of an association for either smoking or obesity remained absent. However, after similar adjustment, the protective effect of history of hypertension actually strengthened slightly (RR = 0.7; CI 0.5–0.9). CONCLUSIONS: Data from this follow-up study of incident RCC cases in Iowa suggests that after adjustment for the strongest independent predictor of survival, a reported history of hypertension is associated with better survival.