Prognostic value of body mass index in Korean patients with renal cell carcinoma

Whether body mass index is a prognostic factor in patients with renal cell carcinoma continues to be debated. We investigated the association between body mass index, and clinical/pathological features and prognosis in a large cohort of Korean patients with renal cell carcinoma.

The medical records of 1,017 patients with renal cell carcinoma who underwent curative surgery between 1988 and 2006 were reviewed. Mean followup was 76.9 months. We analyzed the association of body mass index at surgery with tumor pathological features, and its associations with cancer specific survival and overall survival were evaluated using the Kaplan-Meier method and Cox regression models. Additional survival analysis was performed in a subgroup of 897 patients with T1-4N0M0 disease.

Of the 1,017 patients 363 (35.7%), 526 (51.7%) and 128 (12.6%) had a body mass index of less than 23 (normal), 23 to 27.5 (overweight) and 27.5 or greater (obese) kg/m(2), respectively. Overweight and obese patients had less aggressive tumors, such as less lymph node and/or distant metastases (p = 0.001), low pathological T stage (p = 0.047) and low Fuhrman grade (p = 0.033) vs normal weight patients. In terms of cancer specific survival and overall survival multivariate analysis showed that overweight (p = 0.040 and p = 0.047, respectively) and obese (p = 0.024 and p = 0.010, respectively) patients had good survival rates compared to those with a body mass index in the normal range in the cohort (T1-4NallMall) groups. In addition, overweight (p = 0.022 and p = 0.029, respectively) and obese (p = 0.009 and p = 0.002, respectively) status was significantly associated with cancer specific and overall survival in the T1-4N0M0 groups.

Our findings suggest that overweight and obese Korean patients with renal cell carcinoma have more favorable pathological features and a better prognosis than those with a normal body mass index.