Role of local ablative treatment in oligometastatic non-small cell lung cancer: a meta-analysis

This meta-analysis analyzed the oncologic role of local ablative treatment (LAT) in oligometastatic nonsmall cell lung cancer. METHOD: Pubmed, MEDLINE, Embase, and Cochrane Library were searched until October, 2022. Studies comparing LAT with standard care (control) were included. Sensitivity analyses were performed including randomized controlled studies (RCTs). Subgroup analyses were performed according to specific categories and metastatic burden. The primary endpoints were overall survival (OS) and progression-free survival (PFS). Considering the median OS and PFS from landmark studies, 2-year OS and 1-year PFS rates were used to calculate pooled odds ratios (ORs). RESULTS: A total of 20 studies (four RCTs) encompassing 1750 patients were included. Surgery and radiotherapy (60 and 90% of studies) were mainly used as LATs. Pooled ORs of OS and PFS were 3.492 (95% CI:2.612–4.699, P<0.001) and 3.743 (95% CI: 2.586–5.419, P<0.001), favoring LAT, respectively. Sensitivity analyses, including RCTs showed ORs of 4.111 (P<0.001) and 4.959 (P=0.001) regarding OS and PFS, favoring LCT, respectively. Pooled 1-year and 2-year OS rates were 83.8 and 58.4% in LAT arms, whereas 64.4 and 31% in control arms; pooled 1-year and 2-year PFS rates were 64.6 and 32.8% in LAT arms, and 36.1 and 10% in control arms. In subgroup analyses, the pooled ORs were 3.981 (P<0.001), 3.355 (P<0.001), and 1.726 (P=0.373) in synchronous, oligopersistence, and oligoprogression/recurrence subgroups, respectively. Regarding PFS comparison, pooled ORs were 5.631 (P<0.001), 3.484 (P<0.001), and 1.777 (P=0.07), respectively. According to metastatic burden categories, pooled ORs favored LAT arms in both analyses including low-metastatic and high-metastatic burden subgroups. CONCLUSION: The present study supports the role of LAT in treating nonsmall cell lung cancer oligometastasis. The oligoprogression/recurrence disease could have less LAT benefit than synchronous or oligopersistent disease.