Abstract
OBJECTIVE: To assess the survival benefit of synchronous systemic therapy plus thermal ablation (TA) in oligometastatic colorectal lung metastases (CRLM) and identify independent prognostic factors. BACKGROUND: Optimizing the integration of systemic therapy and TA for potentially curable CRLM remains a significant clinical challenge. METHODS: This study employed a retrospective cohort design, including 326 patients who underwent TA treatment at six tertiary medical centers from March 2014 to October 2022. Patients were categorized into synchronous therapy, upfront ablation, delayed ablation, and no systemic therapy groups based on the timing of systemic therapy relative to TA. Kaplan-Meier analysis and log-rank tests were used to assess survival outcomes. RESULTS: Synchronous systemic therapy yielded the longest median progression-free survival (PFS) (22.0 months) and overall survival (OS) (61.3 months) compared to delayed ablation (13.0 and 49.2 months, respectively) and no systemic therapy (11.9 and 29.3 months, respectively) (all p < 0.05). Synchronous systemic therapy was an independent protective factor for PFS [hazard ratio (HR) = 0.493] and OS (HR = 0.211). Independent risk factors for local tumor progression included tumor size ≥3 cm (HR = 1.75) and peridiaphragmatic location (HR = 1.48). For PFS, independent predictors included tumor numbers (p < 0.001), synchronous metastases (HR = 1.431), and extrapulmonary metastases (p = 0.001). OS was adversely influenced by tumor burden (p < 0.05), extrapulmonary metastases (p < 0.001), and mediastinal lymph node involvement (HR = 1.518). CONCLUSIONS: Synchronous systemic therapy combined with TA significantly enhances PFS and OS in potentially curable oligometastatic CRLM patients.