Purpose: We determine independent prognostic indicators for renal cell carcinoma using the revised 1997 TNM staging criteria.
Materials and methods: The records of 643 consecutive patients undergoing partial or radical nephrectomy at our institution between 1987 and 1998 were reviewed. Preoperative evaluation of functional status using the Eastern Cooperative Oncology Group (ECOG) criteria was performed in all cases. Renal cell carcinoma grade and stage were evaluated using the 1997 American Joint Committee on Cancer grading and TNM staging criteria, respectively. Patients were followed for a mean plus or minus standard deviation of 47+/-40 months (median 87). Kaplan-Meier survival curves were used to determine 5-year cancer specific survival for all patient groups. Univariate analysis using log rank sum tests was performed to evaluate the prognostic significance of overall TNM stage, tumor stage, disease grade and ECOG status. Multivariate analysis was performed to determine which factors had an independent impact on survival of patients with renal cell carcinoma.
Results: The 5-year cancer specific survival rate was 91%, 74%, 67% and 32% for TNM stages I, II, III and IV lesions, respectively (p<0.001). Analysis demonstrated a survival rate of 83% for stage T1, 57% for stage T2, 42% for stage T3 and 28% for stage T4 disease (p<0.001), and 89% for grade 1, 65% for grade 2, and 46% for grades 3 and 4 (p<0.001). Multivariate analysis revealed that overall TNM stage and grade of disease were the most important prognostic indicators for renal cell carcinoma (p<0.001). ECOG classification was a less significant predictor (p = 0.031) and tumor stage was not shown to have any independent impact on patient survival (p = 0.138).
Conclusions: Better survival rates of patients with localized and advanced renal cell carcinoma can be demonstrated with recent advances in diagnosis and treatment. The revised 1997 TNM criteria manifest an appropriate adjustment in staging renal cell carcinoma based on these improvements, with overall stage correlating with cancer specific survival. In contrast, while effectively predicting survival, tumor stage did not demonstrate an independent impact on renal cell carcinoma prognosis under multivariate analysis. Instead, other factors, such as ECOG status and more importantly grade of disease, appeared to affect survival significantly as independent elements. Based on our recent experience with patients treated for renal cell carcinoma in the era of enhanced technology and improved survival, tumor grade and molecular markers may serve as useful adjuncts to TNM staging in guiding treatment and predicting survival outcomes.