Metastasectomy versus stereotactic body radiotherapy for lung metastases: a systematic review and meta-analysis of reconstructed time-to-event data on overall and progression-free survival.

Background: Cancer is the second leading cause of death worldwide, with the majority of cancer-related deaths attributable to metastatic disease. Particularly in patients with pulmonary oligometastases, local ablative treatment strategies such as metastasectomy and stereotactic body radiotherapy (SBRT) are important therapeutic options. However, to date, no randomized controlled trials and only limited direct comparative analyses are available evaluating those treatment options. Therefore, the present study aims to perform a meta-analysis based on reconstructed time-to-event data to compare long-term overall survival (LOS) and progression-free survival (PFS) between these treatment strategies based on currently available evidence. Methods: First, we defined our research question using the PICOTS framework. A systematic literature search of three databases (Ovid MEDLINE, the Cochrane Library, and ScienceDirect) was performed in March 2024 and updated in April 2026. We applied the same predefined search strategy across all databases, which was fully documented. Study selection was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Kaplan-Meier curves were processed, time-to-event data were reconstructed, and overall event curves were generated. A Cox regression model was performed. The risk of bias was addressed using the Newcastle-Ottawa Scale (NOS), and sensitivity analyses were conducted. The risk of publication bias was assessed using a funnel plot. Hazard ratios (HRs) and 95% confidence intervals (CIs) were reported for the estimates. Results: Of 5,480 screened studies, nine met the inclusion criteria. They were published between 2014 and 2025. A total of 1,535 patients were included in the final analysis, of whom 949 underwent surgical metastasectomy and 586 were assigned to SBRT. Compared with SBRT, metastasectomy was associated with improved LOS (HR: 0.74, 95% CI: 0.61-0.90, P=0.002) and long-term PFS (HR: 0.774, 95% CI: 0.66-0.91, P=0.002) in the overall analysis. All included studies were retrospective, with limited sample sizes and variable follow-up. In some cases, systematic differences in patient characteristics, as well as variability in the availability and implementation of treatment protocols, may have introduced additional bias. To address these limitations, a subgroup analysis including only risk-adjusted studies was performed. Within this analysis, there was no significant difference in LOS (HR: 0.70, 95% CI: 0.45-1.10) or long-term PFS (HR: 0.67, 95% CI: 0.39-1.15). Conclusions: This analysis suggests that surgical treatment of lung metastases may be associated with better LOS and PFS compared with SBRT in non-risk-adjusted real-world data, reflecting current treatment allocation and clinical practice. However, when using matched cohorts, both treatment strategies show no difference in LOS or PFS, suggesting that, when applied to the same patient population, they may represent equivalent treatment alternatives. Due to inherent limitations and potential selection bias, further investigation is necessary to confirm these findings.