Renal cell carcinoma recurrences and metastases in primary non-metastatic patients: a population-based study.

Purpose: To present the occurrence of metastases and local recurrences in primary non-metastatic patients with renal cell carcinoma (RCC) in a contemporary Swedish population-based cohort.

Methods: Between 2005 and 2009, a total of 4527 patients were included in the prospective National Swedish Kidney Cancer Register accounting for nearly all RCC patients in Sweden. Among M0 patients, 472 (13 %) had no follow-up data registered within 5-year follow-up time and were excluded from the analysis.

Results: In total, 939 (21 %) had distant metastases at presentation with a decrease from 23 to 18 % during the inclusion period. Of 3107 patients with follow-up data and with M0 disease, 623 (20 %) were diagnosed with a tumor recurrence during 5-year follow-up. Mean time to recurrence was 24 months (SD ± 20 months). Among these, 570 patients (92 %) were at primary diagnosis treated with radical nephrectomy, 23 patients (3.7 %) with partial nephrectomy and 12 patients (1.9 %) with minimally invasive treatments. The most frequent sites of metastases were lung (54 %), lymph nodes (22 %) and bone (20 %). The treatment of recurrence was in 50 % systemic treatments, while metastasectomy was performed in 17 % of the patients, out of which 68 % were with a curative intention.

Conclusions: In this population-based study, 21 % of the patients had metastatic disease at presentation, with a decreasing trend over the study period. During 5-year follow-up, 20 % of the primary non-metastatic patients had recurrent disease. Of the patients with recurrence, half were given systemic oncological treatment and 17 % underwent metastasectomy.