Limited ability of the renal ablation-specific (MC)2 risk scoring system to predict major adverse events from percutaneous renal microwave ablation

•(MC)2 score was not higher in patients with major adverse events, compared to minor or no events.•Tumor size was greater in patients with major adverse events than patients with minor adverse events.•Patients with central tumors were also more likely to experience major adverse events compared to those without central tumors.•(MC)2 score has poor ability to predict major adverse events.•Tumor size and tumor centrality may serve as better predictive factors of major adverse events.