Clinical score for colorectal cancer patients with lung-limited metastases undergoing surgical resection: Meta-Lung Score

Background: Radical resection of isolated lung metastases (LM) from colorectal cancer (CRC) is debated. Like Fong's criteria in liver metastases, our study was meant to assign a clinical prognostic score in patients with LM from CRC, aiming for better surgery selection. Methods: We retrospectively analyzed data from 260 CRC patients who underwent curative LM resection from December 2002 to January 2022, verifying the impact of different clinicopathological features on the overall survival (OS).Results: At the univariate analysis: higher baseline CEA levels (p = 0.0001), disease-free survival less than or equal to 12 months (m) (p = 0.0043), LM size larger than 2 cm (p = 0.0187), multiple resectable nodules (p = 0.0083), and positive nodal status of the primary tumor (p = 0.0011) were associated with worse prognosis. In a Cox regression model, these characteristics retained their independent role for OS (p < 0.0001) and were chosen as criteria to be assigned one point each for clinical risk score. The 5-year survival rate in patients with 0 points was 88%, while no patients with a 5-point score survived at 2 years. Based on the 0-1 vs. 2-5 score range, we obtained a significant difference in median OS: not reached vs. 40.8 months (95 %CI 36 to 87.5), respectively (p < 0.0001) stratifying patients into good and poor prognosis. The prognostic role of the score was also confirmed in terms of median RFS: not reached in 0-1 scored patients vs. 30.5 months (95 %CI 19.4 to 42) in patients with 2-5 scores (p = 0.0006).Conclusions: When LM from CRC is resectable, the Meta-Lung Score provides valuable prognostic information. Indeed, while upfront surgery should be considered in patients with scores of 0 to 1, it should be cautiously suggested in patients with scores of 2 to 5, for whom a prognosis comparison between preventive surgery and other treatments should be investigated in prospective randomized clinical trials.