Abstract
PURPOSE: This study was designed to evaluate and compare the oncological outcomes of patients with pathological T1a (pT1a) small renal cell carcinomas (RCCs) with those with incidental pathological T3a (pT3a) RCCs who have been treated using partial nephrectomy (PN). METHODS: We retrospectively evaluated the records of 1367 consecutive patients who underwent PN for small RCCs (≤4 cm) between 1997 and 2014. The curves for recurrence-free, cancer-specific, and overall survival were estimated using the Kaplan-Meier method. Cox regression analysis was used to estimate the prognostic significance of each variable. RESULTS: Of the 1367 small RCC patients identified, 1324 (96.8 %) had pT1a lesions and 43 (3.2 %) had pT3a lesions. The median ages of the pT1a and pT3a patients were 53.9 and 58.1 years, respectively. Patients received follow-up for a median of 54 months. The 5- and 10-year RFS rates in patients with pT1a and pT3a RCCs were 98.0 and 95.2 %, and 94.4 and 95.2 %, respectively (P = 0.521). None of the patients with recurrent tumors in the pT3a group have died by the time of the writing of this report. A multivariate Cox proportional hazards model showed that tumor size was a significant predictor of RFS and CSS (P < 0.05). However, pT stage (pT3a vs. pT1a) was not a significant predictor of RFS, CSS, or OS (P = 0.104, P = 0.573, and P = 0.441, respectively). CONCLUSIONS: Our study found that pT3a stage disease following PN for small RCCs (≤4 cm) had similar oncological outcomes to those of pT1a stage.