Background: To determine safety and efficacy of radiofrequency ablation (RFA) for local treatment of lung metastases of renal cell carcinoma (RCC), sequenced or combined with systemic treatments.
Methods: Retrospectively, we studied 53 patients treated by RFA for a maximum of six lung metastases of RCC. The endpoints were local efficacy, overall (OS), disease-free (DFS), pulmonary progression-free (PPFS) and systemic treatment-free (STFS) survivals, complications graded by the CTCAE classification and factors associated with survivals. Potential factors analysed were: clinical and pathological data, tumoral staging of TNM classification, primary tumor histology, Fuhrman's grade, age, number and size of lung metastases and extra-pulmonary metastases pre-RFA.
Results: One hundred metastases were treated by RFA. Median follow-up time was 61 months (interquartile range 90-34). Five-year OS was 62% (95% confidence interval (CI): 44-75). Median DFS was 9.9 months (95% CI: 6-16). PPFS at 1 and 3 years was 58.9% (95%CI: 44.1-70.9) and 35.2% (95%CI: 21.6-49.1), respectively. We observed 3% major complications (grade 3 and 4 of CTCAE classification). Local efficacy was 91%. Median STFS was 28.3 months. Thirteen patients (25%) with lung recurrence could be treated by another RFA. T3/T4 tumors had significantly worse OS, PPFS and STFS. Having two or more lung metastases increased the risk of pulmonary progression more than threefold.
Conclusion: Integrated to systemic treatment strategy, RFA is safe and effective for the treatment strategy of lung metastasis from RCC with good OS and long systemic treatment-free survival. RFA offers the possibility of repeat procedures, with low morbidity.
Keywords: Local treatment; Lung metastases; Metastases; Oligometastasis; Radiofrequency ablation; Renal cell carcinoma.