Modifiable risk factors to reduce renal cell carcinoma incidence: Insight from the PLCO trial.

INTRODUCTION: Identify modifiable factors contributing to renal cell carcinoma in the PCLO to target disease prevention and reduce health care costs.

METHODS: The prostate, lung, colorectal, and ovarian database were queried for the primary outcome of kidney cancer. Demographics were investigated, specifically focusing on modifiable risk factors. Statistical analysis includes the Student t-test for continuous variables, chi-squared or Fisher's exact tests for dichotomous and categorical variables for bivariate analysis. The Cox proportional hazards model was used in a multivariate time-to-event analysis.

RESULTS: We investigate existing data relating specifically to renal cancer. After missing data were excluded, we analyzed 149,683 subjects enrolled in the prostate, lung, colorectal, and ovarian trial and noted 0.5% (n = 748) subjects developed renal cancer. Age, male gender, body mass index, diabetes, and hypertension were all significant associated with renal cancer in bivariate analysis (P<0.05). Men have a significant increased risk of kidney cancer over women (hazard ratio [HR] = 1.85; 95% CI: 1.58-2.16; P<0.0001). Nonmodifiable risk factors that are associated with kidney cancer include age (HR = 1.05; 95% CI: 1.01; 1.05, P = 0.001). Modifiable risk factors include obesity measured by body mass index (HR = 1.05; 95% CI: 1.02-1.07; P<0.0001), hypertension (HR = 1.32; 95% CI: 1.13-1.54; P = 0.0004), and smoking in pack-years (HR = 1.04; 95% CI: 1.02-1.07; P = 0.0002).

CONCLUSIONS: Obesity, hypertension, and smoking are the 3 modifiable risk factors that could aggressively be targeted to reduce renal cell carcinoma.