Objective: To evaluate the risk of local recurrence and metastatic spread of renal cancer treated by conservative surgery with a minimum follow-up of 5 years.
Material and methods: All patients operated for renal cancer by conservative surgery in our department between November 1989 and March 1997 were included in this retrospective study and were submitted to annual follow-up. These patients presented conventional indications (solitary T1N0M0 tumours < 4 cm) or indications of necessity (all stages).
Results: The minimum follow-up was 5 years (range: 63-143 months; median: 90 months). This series comprised 30 partial nephrectomies, 15 performed for solitary T1N0M0 tumours < 4 cm, and conservative surgery was performed by necessity in 15 patients (10 patients with T1N0M0 tumours, 5 patients with T2 or M+ tumours). All tumours less than 4 cm on imaging were less than 4 cm on the operative specimen. In stage T1N0M0 tumours, the prediction of pathological stage by preoperative imaging was accurate in 24 out of 25 cases, with 24 pT1N0M0 and 1 pT3aN0M0 on final histology. The resection margins were negative in 29 out of 30 patients. One patients with a stage T2N0M+ tumour (7.5 cm in diameter) had a positive resection margin. Two out of 30 patients developed impaired renal function after surgery to a solitary kidney. Renal function at 3 months remained identical to preoperative renal function in all other patients. For 24 patients with pT1N0M0 tumours < 4 cm, the specific recurrence-free survival was 100% (median follow-up: 90 months; range: 63 to 143 months). Among the 6 patients with T2 or M+ tumours, 5 patients (84%) died from metastatic disease at 18, 22, 24, 28 and 54 months, while 1 patient (16%) was still alive without recurrence at 119 months.
Conclusion: The indication for conservative surgery for T1N0M0 renal tumours < 4 cm is a validated treatment option for unifocal renal cancer. This series confirms the data reported in the literature with a minimum follow-up of 5 years. Stage pT3a tumours on postoperative diagnosis have a high risk of recurrence and metastatic spread, which may constitute an indication for secondary radical nephrectomy. Annual surveillance by imaging is essential.