COMPARISON OF NEPHRON-SPARING SURGERY IN CENTRAL VERSUS PERIPHERAL RENAL TUMORS MICHAEL MULLERAD, ALEXANDER KASTIN, PRASAD S. ADUSUMILLI, BOAZ MOSKOVITZ, EDMOND SABO, AND OFER NATIV ABSTRACT Objectives. To determine the feasibility of nephron-sparing surgery (NSS) in patients with centrally located tumors. Methods. A retrospective cohort study of 118 patients who underwent NSS between 1993 and 2002 (35 patients with centrally located tumors and 83 with peripherally located tumors) was performed. Kaplan- Meier curves were constructed to evaluate freedom from local recurrence and disease-specific survival in patients with conventional histologic subtype tumors. The Wilcoxon test was used to compare the curves (two-tailed P 0.05 was considered to be statistically significant). Results. Intraoperatively, in patients with centrally located tumors, the need to close the collecting system (P = 0.035) and for blood transfusions (P = 0.033) was greater. Two perioperative deaths occurred in patients with peripherally located tumors. Two patients with centrally located tumors subsequently under- went nephrectomy. Of the patients with centrally located tumors, 1 patient had a positive margin, 2 patients had local recurrence, and 1 patient developed metastasis. No positive surgical margins or local recurrence was found in patients with peripherally located tumors, although 4 patients developed distant metastasis. Kaplan-Meier curves for patients with conventional histologic subtype tumors demonstrated a statistically significant difference for local recurrence (P = 0.04), but not for survival (P = 0.71). The mean follow-up time was 38.8 and 43.8 months for patients with centrally located and peripherally located tumors, respectively. Conclusions. NSS can be used to postpone, or eliminate the need for, nephrectomy in 94.3% of patients with centrally located tumors and can achieve oncologic disease control similar to that for exophytic lesions. These data indicate that NSS should be considered even for patients with centrally located tumors, taking into account that performing such surgery is a challenging task. UROLOGY 65: 467–472, 2005. © 2005 Elsevier Inc. K idney tumors account for 2% of cancer inci- dence in the United States, contributing to 12,000 deaths per year, 1 and 80% of these tumors are located in the renal parenchyma. The introduc- tion of new imaging modalities in the past two decades resulted in a significant increase in the diagnosis of localized tumors grouped with an an- nual increased incidence rate of 3.8% to 5.0%. 2 The natural history of small renal masses is not entirely clear. A study by Rendon et al. 3 suggested that the course of the disease for renal cortical tu- mors is unpredictable and aggressive tumor behav- ior can be observed at an early or late stage. The standard of care for renal cortical tumors has been total resection of the kidney along with Gerota’s fascia. These patients are at increased risk (approx- imately fourfold) of developing renal insufficiency over time compared with patients who undergo partial nephrectomy. 4 Long-term follow-up data from 15 studies of 611 patients treated with nephron-sparing surgery (NSS) reported accept- able local tumor control, with an overall local re- currence rate of 0% to 7.3% (mean follow-up 35 to 120 months). 5,6 Studies aimed at defining risk factors for local recurrence revealed that tumor size is associated with multicentricity and subsequent outcome. 7,8 A maximal tumor diameter of 4 cm has gained wide From the Department of Urology, Bnai-Zion Medical Center, Technion-Israel Institute of Technology Rappaport Faculty of Medicine, Haifa, Israel; Department of Surgery, Memorial Sloan- Kettering Cancer Center, New York, New York; and Department of Pathology, Carmel Medical Center, Haifa, Israel Reprint requests: Ofer Nativ, M.D., Department of Urology, Bnai Zion Medical Center, 47 Golomb Street, P.O. Box 4940, Haifa 31048, Israel. E-mail: dr_nativ@netvision.net.il Submitted: April 27, 2004, accepted (with revisions): October 18, 2004 ADULT UROLOGY © 2005 ELSEVIER INC. 0090-4295/05/$30.00 ALL RIGHTS RESERVED doi:10.1016/j.urology.2004.10.063 467