Similar functional outcomes after partial nephrectomy for clinical T1b and T1a renal cell carcinoma

OBJECTIVES: To examine the medium-term functional outcomes of partial nephrectomy for clinical T1b renal cell carcinoma, and to compare them with those of radical nephrectomy for clinical T1b and with those of partial nephrectomy for clinical T1a tumors. METHODS: The participants of this study were patients operated for clinical T1a and clinical T1b tumors operated at Tokyo Women's Medical University, Tokyo, Japan, between January 1979 and June 2011. A total of 67 patients underwent partial nephrectomy for clinical T1b tumor, 195 patients underwent radical nephrectomy for clinical T1b tumors and 324 underwent partial nephrectomy for clinical T1a tumors. The outcomes of these three groups were compared. RESULTS: Partial nephrectomy provided better preservation of residual renal function compared with radical nephrectomy for clinical T1b, and the postoperative estimated glomerular filtration rate was similar in the patients who underwent partial nephrectomy for clinical T1b and those who underwent partial nephrectomy for clinical T1a. Postoperative renal function was steadily maintained after partial nephrectomy during the medium-term follow up. The probability of freedom from new onset of chronic kidney disease after partial nephrectomy for clinical T1b tumors was significantly higher from that after radical nephrectomy for clinical T1b tumors, and similar to that after partial nephrectomy for clinical T1a tumors. CONCLUSIONS: The higher anatomical complexity of clinical T1b tumors is unlikely to provide a significant influence on postoperative renal function after partial nephrectomy, when compared with the clinical T1a tumors. These findings support the beneficial role of partial nephrectomy in the preservation of renal function of clinical T1b renal cell carcinoma patients undergoing surgery.