The Value of Tumor Size as a Prognostic Factor in Patients with Localized Renal Cell Carcinomas

Kim, Dae Sung; Woo, Young Nam; Lee, Tchun Yong

Abstract

PURPOSE: In the TNM staging system of renal cell carcinomas, the tumor size has been considered an important prognostic factor in predicting the survival of patients with localized renal cell carcinomas. We tried to determine a size cutoff point that maximizes its value as a prognostic factor.
MATERIALS AND METHODS
We reviewed the records of 70 patients who had undergone a radical nephrectomy for a renal cell carcinoma, and were pathologically classified as stage I (T1N0M0) and II (T2N0M0) carcinomas, based on the 1997 TNM staging system, between May 1987 and December 1998. Of the 70 patients, there were 50 men and 20 women, with a mean age of 52.4 years (range 35 to 78 years). The postoperative follow-ups ranged from 10 to 170 months, with a mean of 83 months. The survival curves were calculated by the Kaplan-Meier method at a 7cm cutoff point. The patients were divided into two groups for each size cutoff point from 2.5 to 9cm by 0.5cm intervals. The statistical significance of difference in 5-year survivals between the groups was calculated by log rank tests.
RESULTS
Of the 70 patients, metastases occurred in 7 (5 lung, 1 brain and 1 liver and bone). From the analysis of survival based on tumor size, no statistically significant differences were noted between the size cutoff points. With a present tumor size cutoff point of 7cm, the Fuhrman nuclear grade (p=0.01) was the only statistically different factor between the two groups, with no statistical difference between the two groups for: patient age, sex, tumor histopathology or microscopic intrarenal vascular invasion. Although, there was a significant difference in the 5-year survival in the microscopic intrarenal vascular invasion (p=0.03) and the other prognostic factors.
CONCLUSIONS
Tumor size had no significant influence on the survival of patients with localized renal cell carcinomas treated by a radical nephrectomy.