Prognostic factors after R0 resection of colorectal cancer liver metastases: A systematic review and pooled-analysis

Background: Prognostic variables associated with outcome after curative (R0) Resection of Colorectal Cancer (CRC) liver metastases are paramount in identifying high-risk patients after surgery. The aim of this study was to identify risk factors related to Overall Survival (OS) after R0 resection of CRC liver metastases. Methods: A literature search on prognostic factors after resection of liver metastases was performed. Studies were eligible if covariates associated with OS were reported in patients with R0 resected CRC liver metastases. Independent prognostic factors associated with OS were identified using multivariate analysis. Results: Twenty-four publications with a total of 4855 patients were eligible. In multivariate analyses, a disease-free interval < 12 months (hazard ratio [HR] 1.47, P = 0.0002), the size of the largest metastasis (HR 1.56, P < 0.0001), the total number of metastases (HR 1.73, P < 0.00001), a primary tumor with node-positive status (HR 1.56, P = 0.002), a rectal primary tumor (HR 1.48, P < 0.00001), a high carcinoembryonic antigen level (HR 1.49, P = 0.02), a high tumor grade (HR 2.42, P < 0.00001), and extrahepatic disease (HR 2.03, P < 0.00001) were associated with an increased risk of death after R0 resection of CRC liver metastases in at least 3 studies. Conclusion: We identified 9 clinicopathological prognostic factors that could help identify high-risk patients and guide further treatment and follow up decisions. In particular burden of liver and extrahepatic metastases and grade are those associated with a higher risk of death.