Risk factors for recurrence after operation in patients with pT1a renal cell carcinoma: Sub-analysis of the multi-institutional national database of the Japanese Urological Association

Background: More patients with renal cell carcinoma are now diagnosed with the disease in its early stages. Although patients with pT1a renal cell carcinoma have a good prognosis and low recurrence rate, a few patients still experience recurrence. Herein, we evaluated the clinicopathological risk factors for postoperative recurrence of pT1aN0M0 renal cell carcinoma. Methods: An renal cell carcinoma survey was conducted by the Japanese Urological Association to register newly diagnosed cases of renal cell carcinoma. A total of 1418 patients diagnosed with pT1aN0M0 renal cell carcinoma who underwent surgery as the primary surgical treatment were included. We analyzed the recurrence-free survival using the Kaplan-Meier method and clinicopathological factors for recurrence using Cox proportional hazards models. Results: Among 1418 patients, 58 (4.1%) had recurrences after a median follow-up of 62.8 months. The median time to recurrence was 31.0 months. Metastases to the lungs and the bone were observed in 20 and 10 cases, respectively. Significant differences in sex, tumor size, Eastern Cooperative Oncology Group performance status, and dialysis history, preoperative hemoglobin levels, C-reactive protein levels and creatinine levels were observed between the recurrence and non-recurrence groups. Multivariate analysis identified male sex, high C-reactive protein level and tumor size ≥3 cm as independent risk factors. The 5-year recurrence-free survival of patients with 0, 1, 2 and 3 risk factors was 99.0, 97.2, 93.1 and 80.7%, respectively. Conclusions: Male sex, tumor diameter and a high C-reactive protein level were independent recurrence risk factors for pT1a renal cell carcinoma; special attention should be paid to patients with these risk factors during postoperative follow-up.