MANAGEMENT OF SMALL SOLITARY UNILATERAL RENAL-CELL CARCINOMAS - IMPACT OF CENTRAL VERSUS PERIPHERAL TUMOR LOCATION

Recent studies have suggested that nephron sparing surgery and radical nephrectomy provide equally effective therapy for patients with small (less than 4 cm.), solitary, unilateral renal cell carcinoma and a no rmal contralateral kidney. We evaluate whether central versus peripher al tumor location in the involved kidney is a significant factor affec ting treatment outcome in these patients. Materials and Methods: Patie nts with a single, small (less than 4 cm.), localized, unilateral, spo radic renal cell carcinoma were identified from our institutional regi stry. From 1972 to 1995, 145 patients fulfilling these criteria were t reated with either nephron sparing surgery (86) or radical nephrectomy (59). Mean postoperative followup was 51.4 months. Tumor characterist ics and outcome measures were analyzed in 35 patients with central ver sus 110 with peripheral renal cell carcinomas according to the type of treatment. Results: We detected 27 central (77%) and 75 peripheral re nal cell carcinomas (68%) incidentally. Nephron sparing surgery was us ed to treat 19 central (54%) and 67 peripheral (61%) carcinomas. Patho logical tumor stage was T1 to 2 in 33 central (94%) and 91 peripheral (82%) cases. Grade 1 to 2 renal cell carcinoma was present in 28 centr al (80%) and 85 peripheral (77%) tumors. Postoperatively, when compari ng patients with central versus peripheral renal cell carcinomas there was no difference in 5-year cancer specific survival (100 versus 97%) , tumor recurrence (5.7 versus 4.5%) or renal function (mean serum cre atinine 1.43 mg./dl, in both groups). These parameters were also equiv alent in patients treated with nephron sparing surgery versus radical nephrectomy overall and within the central versus peripheral renal cel l carcinoma subgroups. Nephron sparing surgery was technically more co mplicated in central renal cell carcinomas with a longer renal ischemi a time (55 versus 34 minutes, p <0.05) and more frequent entry of the collecting system (74 versus 47%, p <0.05) compared to peripheral carc inomas. Two patients (2.3%, 1 central, 1 peripheral) had local tumor r ecurrence after nephron sparing surgery. Conclusions: There were no si gnificant biological differences between centrally versus peripherally located small solitary unilateral renal cell carcinomas. Nephron spar ing surgery is technically more demanding in patients with central tum ors. However, treatment with nephron sparing surgery or radical nephre ctomy is equally effective regardless of tumor location.