Safety and efficacy of thermal ablation for small cell lung cancer liver metastases

Small cell lung cancer (SCLC) is a high-grade neuroendocrine carcinoma associated with early development of distant metastases, which portends a worse prognosis. The median survival of metastatic SCLC with standard treatment is only 9-11 months, with a 5-year survival of 1-2%. Patients with SCLC are often initially responsive to systemic therapies, but once they develop resistance to them, locoregional therapies like thermal ablation should be investigated for possible improvements in morbidity and mortality. This brief retrospective report evaluates six patients with SCLC liver metastases (LMs), treated in 11 thermal ablation sessions (radiofrequency ablation or microwave ablation). Technical success was achieved in all treatments (100%). After the first ablation, 3/7 ablated tumors had residual disease. Survival outcomes were determined using the Kaplan-Meier method. Median local tumor progression-free survival (LTPFS) was 2.9 [95% confidence interval (CI): 0.5-3.9] months. Median assisted LTPFS, defined as tumor control with subsequent retreatment, was 25.9 (95% CI: 8.3-not reported) months. Median overall survival (OS) was 14.3 months. There was one adverse event (1/11) of grade 1, according to the Common Terminology Criteria for Adverse Events version 5.0, fatigue within a month of ablation, which self-resolved. The results suggest that thermal ablation is safe for SCLC LMs. Although LTPFS was very modest, the long duration of assisted LTPFS and OS in this small, retrospective study suggests that thermal ablation may be a promising treatment option.