Prognosticfactors in patients with renal cell carcinoma: is TNM (1997) staging relevant in Indian subpopulation?

BACKGROUND: RCC (Renal Cell Carcinoma) is a common genitourinary malignancy, but its behavior has not been studied in the Indian Subpopulation. AIMS: The aim of this study was to assess the validity of 1997 AJCC TNM staging in Indian subpopulation and also to identify independent predictors for survival in patients having RCC. SETTING AND DESIGN: Retrospective uncontrolled analysis of patients with RCC was performed at our centre. MATERIAL AND METHODS: Medical records of patients of undergoing radical nephrectomy at our center between 1994 to August 2003 were identified retrospectively. Medical records of 178 patients were available for analysis. Patient characteristics, preoperative imaging and surgical details were reviewed. Each tumor was staged according to the 1997 AJCC TNM classification. Nuclear grade was assigned according to the Fuhrman's grading system. STATISTICAL METHODS: Statistical analysis was performed using statistical software and descriptive statistics and survival functions were obtained. Univariate and multivariate analysis of factors affecting outcome of the patient were performed. RESULTS: Mean follow up period was 42.3 months (range 3 to 108 months). Stage wise 5-year Cancer specific survival was 87.2% in stage 1 disease, 74.3% in stage 2, 36.4% in stage 3 and 3.1% in stage 4. Univariate analysis revealed that stage, grade and lymph node status were statistically significant (P=0.009, 0.007 and 0.003 respectively). Sub-classifying stage 1 tumors between tumor of less than 4 cm. and more than 4 cm. did not reveal any statistically significant difference in survival (P=0.32). Multivariate analysis model revealed that Fuhrman's grade and lymph node status were statistically significant (P=0.007 and 0.002 respectively). CONCLUSION: This study validates the TNM (1997) staging for RCC as having significant survival impact in the Indian subpopulation. Sub-classifying stage 1 tumors between tumor of less than 4 cm. and more than 4 cm is not of much importance. Nuclear grade and lymph node involvement are important independent predictors of survival. Organ confined tumors with high nuclear grades need to be followed up more rigorously.