The Benefit Of Locally Ablative Treatment In Lung Metastasis From Colorectal Cancer

Abstract

Despite emerging evidence of locally ablative treatment (LAT) in oligometastatic setting, diagnosis-specific data are needed to convince in multi-disciplinary daily practices. Recently published randomized controlled trial (PulMiCC, n = 65) raises doubts about the benefit of lung metastasectomy in lung metastasis from colorectal cancer (CRC). In this reason, we aimed to study whether LAT had an independent impact on survival in this clinical setting. From 2010 to 2017, 1,262 patients were diagnosed as lung metastasis from CRC in a highly experienced single institution. Lung metastasis-directed locally ablative treatment (LAT) has increased with an average annual increase of 12% during study period. A total of 463 patients (36.6%) received LAT: surgical resection 373 cases, SABR 66 cases, and both 24 cases. Primary end-point was overall survival (OS), defined as the time from the date of diagnosis of lung metastasis. The number of pulmonary and extrapulmonary metastases were reviewed and counted in CT images, retrospectively. The median follow-up period was 45.2 months (IQR, 29.3-79.0). Patients who underwent LAT had younger age, normal CEA level, a smaller number of pulmonary and/or extrapulmonary metastasis (all P < .05). Most LAT patients had ≤5 lung metastases (95.3%) and controlled/no extrapulmonary metastases (80.5%) compared to no LAT group (52.2% and 13.5%, respectively; all P < .05). 10-year OS was 43.2% (35.8% to 50.6%) and 1.6% (0.4% to 2.8%) in patients with or without LAT (P <.001). In the LAT group, 65 (14%) patients also received salvage LAT to new metastasis on disease progression (surgical resection 44 cases and SABR 21 cases). In multivariate analysis, LAT showed independent survival benefit after adjusting all confounding variables (HR 0.29, P < .001). Additionally, higher Charlson comorbidity index, increased numbers of lung metastases, and increased numbers of extrapulmonary metastases were significantly associated with inferior OS (all P < .05). LAT to the lung metastasis may provide significant disease control for selected patients. In this large dataset, estimated survival at 10 years for LAT group was 43%, which seems greater than has been assumed. As systemic therapy and imaging advances better present the patients with lower disease burden, we believe that the debate could move on from “whether to treat” to “who, when, and how to treat”.