Efficacy of Partial Nephrectomy for Renal Tumors >4 cm: Comparison With Renal Tumors ≤4 cm

Partial nephrectomy has become a treatment of choice for clinical T1a renal masses. Some international guidelines suggest that partial nephrectomy can be applied also in clinical T1b tumors. The aim of this study was to evaluate the feasibility of partial nephrectomy for tumors larger than 4 cm. We reviewed the medical records of 1280 patients who underwent partial nephrectomy and had pathologically confirmed malignancy. Patients were categorized into two groups by the size of tumors on computed tomography image, with a cutoff value of 4 cm. The oncologic and functional outcomes were compared between the two groups. Recurrence-free survival after surgery was estimated using the Kaplan-Meier method. Of the 1280 patients, 203 patients (15.9%) had renal tumors larger than 4 cm. There were significantly more exophytic tumors (P<0.001) and the R.E.N.A.L. scores were significantly higher (P<0.001) in partial nephrectomy >4 cm. Mean ischemic times were significantly different (P<0.001). After 24 months, mean creatinine level between partial nephrectomy >4 cm and partial nephrectomy <= 4 cm was not different significantly (P=0.554). And the percent changes of glomerular filtration rate after partial nephrectomy were not different at last follow-up (P=0.082). The 5-year recurrence-free survival rates were 96.6% in partial nephrectomy <= 4 cm, and 94.5% in partial nephrectomy. > 4 cm (P = 0.416). Based on the present findings, partial nephrectomy for tumors larger than 4 cm showed comparable feasibility and safety to partial nephrectomy for tumors <= 4 cm considering oncologic and functional outcomes, despite longer operative and ischemic time.