Radical Nephrectomy Provides a Worse Prognosis Than Partial Nephrectomy in T3aN0M0 Renal Cancer of Small (≤4 cm) Size and No Invasion of Perisinus Fat

Abstract Background: Radical nephrectomy (RN) is the recommended treatment for T3aN0M0 renal cell carcinoma (RCC). However, it is not necessarily the best treatment for small T3aN0M0 RCCs. We evaluated the effect of tumor size combined with consideration of anatomic types of extrarenal-fat invasion on the surgical decision-making between partial nephrectomy (PN) vs. RN in T3aN0M0 RCC.Methods: Data were obtained from the Surveillance, Epidemiology, and End Results database (2004 to 2015) with 6125 patients suffering from T3aN0M0 RCC. Cox and Fine and Gray models were used for survival analyses. Propensity-score matching was used for PN vs. RN.Results: A larger T3aN0M0 RCC was associated with higher risk of mortality (hazard ratio (HR)all-cause mortality: 1.07, 95% confidence interval (CI): 1.02–1.13, P = 0.011; HRRCC-cause mortality: 1.13, 95%CI: 1.06–1.21, P < 0.001) compared with a small T3aN0M0 RCC. After propensity-score matching, in T3aN0M0 ≤4 cm, RN compared with PN significantly increased the risk of death (HR: 1.77; 95%CI: 1.14–2.74, P = 0.011) and offered no significant difference in RCC-specific survival (HR: 1.57, 95%CI: 0.74–3.36, P = 0.240). However, RN and PN showed no significant difference in overall survival in T3aN0M0 RCC >4 cm (HR: 0.98; 95%CI: 0.59–1.62, P= 0.929) or in T3aN0M0 RCC with sinus/perisinus-fat invasion (HR: 1.18; 95%CI: 0.61–2.27, P = 0.631).Conclusion: PN provided better overall survival compared with RN for small (≤4 cm) T3aN0M0 RCCs without sinus/perisinus-fat invasion. Focusing only on anatomic-invasion characteristics rather than type and tumor size is not sufficient for treatment decisions in T3aN0M0 RCC.