The impact of metastasectomy on survival of patients with synchronous metastatic renal cell cancer in Finland: A nationwide study.

Background and objective: Most of the studies on metastasectomy in renal cell cancer are based on metachronous, often oligometastatic disease. Prior data on the impact of metastasectomy in synchronous metastatic renal cell cancer (mRCC) is, however, very scarce. We aimed to investigate the role of complete and incomplete metastasectomy in a large, nationwide patient population.

Methods: We analyzed nationwide data, including all synchronous mRCC cases in Finland diagnosed during a 6-year period identified from the Finnish Cancer Registry, and complemented with patient records from the treating hospitals. We only included the patients who underwent removal of the primary tumor by nephrectomy. We performed univariate and multivariable adjusted analysis to identify the effect of metastasectomy on overall survival (OS) and cancer-specific survival (CSS).

Results: We included 483 patients with synchronous mRCC. Overall, 57 patients underwent complete and 96 incomplete metastasectomy, while 330 patients had no metastasectomy. The median OS was 17.9 and CSS 17.2 months for all patients. The median OS and the median CSS were 59.3 and 60.8 months for the complete, 21.9 and 25.1 for the incomplete, and 14.5 and 14.8 months for the no metastasectomy groups (p < 0.001 for differences). In both applied multivariable statistical models, the OS and CSS benefit from complete metastasectomy remained significant (hazard ratios (HRs) varied between 0.42 and 0.54, p < 0.001) compared with the no metastasectomy group. However, there was no improvement in survival estimates in the incomplete metastasectomy group compared with the no metastasectomy group (HRs varied between 1.04 and 1.10, p > 0.40).

Conclusions: Complete metastasectomy, when possible, can be considered as a treatment option for selected patients with synchronous mRCC who are fit for surgery. By contrast, we found no survival benefit from an incomplete metastasectomy suggesting that such procedures should not be performed for these patients.