Age at diagnosis as a powerful predictor for disease recurrence after radical nephrectomy in Japanese patients with pT1 renal cell carcinoma

Objectives: To review clinical outcomes and to identify clinicopathological variables as predictors of disease recurrence in a cohort of Japanese patients undergoing radical nephrectomy for renal cell carcinoma (RCC). Methods: The present study included a total of 710 consecutive Japanese patients who underwent radical nephrectomy and were diagnosed as having localized pT1 RCC. The significance of several clinicopathological factors in predicting postoperative disease recurrence was assessed by univariable and multivariable analyses. Results: Median age was 66 years (range 32-90 years). Open and laparoscopic radical nephrectomies were carried out for 436 (61.4%) and 274 (38.6%) patients, respectively. Tumor size was 4 cm or less in 461 (64.9%) patients and greater than 4 cm and 249 (35.1%) patients. During the observation period (median 36 months; range 3-111 months), postoperative disease recurrence developed in 37 patients (5.2%), of whom 10 (1.4%) died of disease progression. The 1-, 3- and 5-year recurrence-free survival rates were 98.3%, 95.0% and 92.7%, respectively. Age at diagnosis and tumor size were found to be significantly associated with recurrence-free survival at both univariable and multivariable analysis. Furthermore, there were significant differences in the recurrence-free survival with respect to both independent predictors. Conclusions: Age at diagnosis in addition to tumor size appears to be independently related to disease recurrence in Japanese patients with pT1 RCC. Thus, an intensive follow up for older patients seems to be advisable.