Nephron sparing surgery for localized renal cell carcinoma: Impact of tumorsize on patient survival, tumor recurrence and TNM staging

Purpose: We studied the impact of tumor size on patient survival and tumor recurrence following nephron sparing surgery for localized sporadic renal cell carcinoma. In addition, we evaluated the usefulness of the new TNM: staging system in which T1 versus T2 tumor status is delineated by tumor size 7 or less versus more than 7 cm., respectively. Materials and Methods: The results of nephron sparing surgery for localized sporadic renal cell carcinoma in 485 patients treated before 1997 were reviewed. Patients were divided into groups according to tumor size as 1-2.5 or less (142), 2-2.5 to 4.0 (168), 3-more than 4 to 7 (125) and 4-more than 7 cm (50). Mean postoperative followup was 47 months. Results: Overall and cancer specific 5-year survival for the entire series was 81 and 92%, respectively. Of 44 patients with recurrent renal cell carcinoma 16 (3.2%) had local recurrence and 28 (5.8%) had metastatic disease. There was no difference in 5-year cancer specific survival or tumor recurrence between groups 1 and 2 or groups 3 and 4. However, these outcome measures were significantly more favorable in groups 1 and 2 combined (tumors 4 cm. or less) compared to groups 3 and 4 combined (tumors more than 4 cm.) (p = 0.001). Conclusions: Following nephron sparing surgery for localized sporadic renal cell carcinoma cancer-free survival is significantly better in patients with tumors 4 cm. or less compared to those with larger tumors. The usefulness of the current TNM staging system can be improved by subdividing T1 tumors into Tla (4 cm. or less) and T1b (4 to 7 cm.).