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

Abstract

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 ¼ 0.554). And the percent changes of glomerular filtration rate after partial nephrectomy were not different at last follow-up (P ¼ 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 ¼ 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. Key words: Glomerular filtration rate -Kidney neoplasms -Nephrectomy -Partial -Size H istorically, radical nephrectomy has been established as the standard treatment for localized renal cell carcinoma.1 Renal cancer does not represent a single disease, but a compendium of a complex family of tumors, with variable metastatic potential ranging from benign tumor to clear cell carcinoma.2 Therefore, the rationale of radical nephrectomy for 20% to 30% of patients with benign or low malignant potential renal tumors has been questioned. Partial nephrectomy (PN), or nephronsparing surgery, has become a treatment of choice for clinical T1a renal masses and has been shown to provide comparable oncologic outcomes.3 In addition, PN offers lower renal function impairment compared with radical nephrectomy. 4 As a result, the prevention of chronic kidney disease possibly helps to obtain a better overall survival, and constitutes a wider use of PN. And some international guidelines suggest that PN can be applied also in clinical T1b tumors. 5,6 The European Association of Urology guidelines have recommended PN as an alternative treatment for single renal mass larger than 4 cm, if possible. 5 The American Urological Association guidelines have suggested that PN could be helpful for T1b tumors in patients whose renal function needs to be preserved. 6 Furthermore, a recent study was reported providing...