Comparison of the prognosis between pT3a only patients with perirenal fat invasion and T1/T2 patients, respectively: Is it necessary to revice state T3a?

Purpose: As compared with pathologic stages T1 and T2, we aimed to investigate the difference of the prognosis for the patients with perirenal fat invasion (pT3a), and the patients were divided into two groups by the tumor size of 7cm. Materials and Methods: Of the 503 patients who underwent an operation for renal cell carcinoma between June 1995 and April 2004, we retrospectively reviewed the records of 455 patients with T1, T2 and T3a stage renal cell carcinoma without adrenal invasion. We evaluated the cell type, the multifocality of the tumor, the nuclear grade, the presence of a sarcomatoid component and the coagulative histologic necrosis. We divided the patients with pT3a renal cell carcinoma into two groups according to the tumor size of 7cm (Group 1; ≤ 7cm pT3a, Group 2; > 7cm pT3a). The overall survival was estimated using the Kaplan-Meir method and the log-rank test. We used Student's t-test to compare each factors between groups 1 and 2 and the T1 and T2 groups, respectively. The prognostic factors that had an influence on survival were estimated using the Cox proportional hazard regression model in each group. Results: After the exclusion criteria (the presence of adrenal invasion in pT3a patients) were applied, 24 patients were in group 1, 23 patients were in group 2, 328 patients had pT1 disease and 80 patients had pT2 disease. The median follow-up was 45.4 months. When group 1 was compared to the pT1 group, there was no significantly difference of the estimated survival (p=0.21). There was a similar result when comparing the estimated survival between group 2 and the pT2 group (p=0.80). Conclusions: No significant difference exists for the disease specific survival when patients with pT3a disease (Groups 1 and 2) are compared to the patients with either pT1 or pT2 disease. These findings reveal that patients with pT3a disease without adrenal invasion have similar outcomes to patients with either with pT1 or pT2 disease. Therefore, our result suggests that pT3a tumor should be re-classified according to tumor size into pT3a without adrenal invasion.