Recurrences after nephron-sparing treatments of renal cell carcinoma: a competing risk analysis.

Purpose: To examine associations between ablative therapy (AT) and partial nephrectomy (PN) and the occurrence of local recurrence (LR), distant metastatic recurrence (DMR) and all-cause mortality in a nation-wide real-world population-based cohort of patients with nonmetastatic renal cell carcinoma (nmRCC).

Methods: Data on 2751 AT- or PN-treated nmRCC tumours diagnosed during 2005-2018, representing 2701 unique patients, were obtained from the National Swedish Kidney Cancer Register. Time to LR/DMR or death with/without LR/DMR was analysed using Cox regression models.

Results: During a mean of 4.8 years follow-up, LR was observed for 111 (4.0%) tumours, DMR for 108 (3.9%) tumours, and death without LR/DMR for 206 (7.5%) tumours. AT-treated tumours had a 4.31 times higher risk of LR (P < 0.001) and a 1.91 times higher risk of DMR (P = 0.018) than PN-treated, with no significant differences in risk of death without LR/DMR. During a mean of 3.2 and 2.5 years of follow-up after LR/DMR, respectively, 24 (21.6%) of the LR cases and 56 (51.9%) of the DMR cases died, compared to 7.5% in patients without LR/DMR. There were no significant differences between AT- and PN-treated regarding risks of early death after occurrence of LR or DMR.

Conclusion: AT treatment of patients with nmRCC implied significantly higher risks of LR and DMR compared with PN treatment. To minimize the risks of LR and DMR, these results suggest that PN is preferred over AT as primary treatment, supporting the EAU guidelines to recommended AT mainly to frail and/or comorbid patients.