Salvage R0 Resection on Post-Recurrence Survival After Pulmonary Metastasectomy for Colorectal Cancer: A Multicenter Retrospective Study.

Abstract

Although pulmonary metastasectomy is an established treatment for colorectal cancer, recurrence is frequent. Repeat resection for hepatic recurrence is a recognized paradigm, but the clinical significance of salvage surgery for pulmonary recurrence remains less defined. This study evaluated recurrence patterns and the association with salvage R0 resection on post-recurrence survival using a time-dependent model. We retrospectively reviewed 182 patients who achieved R0 resection at their initial pulmonary metastasectomy at two institutions between 2008 and 2022. Post-recurrence survival was calculated from the date of first recurrence. To account for immortal time bias, salvage R0 resection was modeled as a time-dependent covariate in a multivariable Cox model. Recurrence occurred in 76 patients (41.8%). Single-organ recurrence was observed in 80.3%, with the lung being the most frequent site (42.6%) among single-organ recurrences. Salvage R0 resection was achieved in 33 patients (43.4%), all of whom had single-organ recurrence. The 5-year post-recurrence survival was significantly higher in the salvage R0 group than in the non-R0 management group (53.0% vs. 14.6%; log-rank p < 0.001). In the time-dependent multivariable analysis, achieving salvage R0 resection was independently associated with improved post-recurrence survival (hazard ratio 0.359; 95% confidence interval 0.163-0.794; p = 0.011). Six patients remained recurrence-free for over 5 years after salvage R0 resection without systemic therapy. Achieving salvage R0 resection provides a significant survival benefit comparable to repeat hepatectomy outcomes. For patients with single-organ recurrence after pulmonary metastasectomy, aggressive local intervention aimed at R0 resection should be considered a key therapeutic strategy.