The Dilemma of the Disappeared Colorectal Liver Metastasis: Systematic Review of the Systematic Reviews

Abstract

Introduction: Colorectal liver metastasis (CRLM) contributes to approximately 50% of metastasis related mortality in patient with colorectal cancer. Tumour response to chemotherapy has significantly improved. As a results, a phenomenon termed “disappearing Colorectal Liver Metastases” (dCRLM) develops. The aim of this study is to evaluate if the best management of dCRLM could be recommended from the available literature. Method: English language published literature was searched with no restriction on date. Systematic reviews were the primary target for inclusion. The main outcomes were recurrence free survival (DFS), overall survival (OS) for both treated lesions and those underwent surveillance, complete pathological response (CPR) in resected dCRLM and sensitivities of different imaging modalities. Meta-analysis was conducted. Results: Out from 38 records, only 7 reviews were included. The standard contrast enhanced computed tomography (CE-CT) was inferior to high-resolution gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) in detecting CRLM after chemotherapy. Preoperative imaging is twice as likely to miss dCRLM as intraoperative imaging. Out of 919 surgically resected dCRLMs, 389 (42.3%) (IQR: 27.9-65.8%) achieved CPR. Out of 472 dCRLMs left in situ, 153 (32.4%) had recurrence (IQR: 20.5-57.8%). Conclusion: The best management for dCRLM could not be recommended due to the low quality of literature . However, trends are observed for better outcomes with surgery for patients with CPR. CPR could be induced by Hepatic artery infusion. EOB-MRI should be a preferred preoperative imaging modality for patients with CRLM and CE-IOUS could be an alternative.Tabled 1EP01A-068ComparisonResultRisk of missing CRLM after chemotherapy: CE-CT vs EOB-MRIRisk ratio: 2.26, CI (1.16-4.39), P<0.00001Risk of missing CRLM after chemotherapy: EOB-MRI vs Contrast enhanced intraoperative ultrasound (CE-IOUS)Risk ratio: 1.10,CI (0.99-1.23), P=0.08Risk of missing dCRLM: CE-IOUS vs Intraoperative ultrasound (IOUS)Risk ratio: 0.42, CI (0.16-1.07), P=0.07Risk of missing CRLM after chemotherapy: Preoperative vs intra-operative imagingRisk ratio: 2.52,CI (1.80-3.50), P<0.00001Risk of not acheiving CRR : Hepatic artery infusion (HAI) chemotherapy vs non-HAI chemotherapyRisk ratio:0.72, CI(0.51-1.01),P=0.06Risk of not achieving CPR in resected lesions: HAI chemotherapy vs non-HAI chemotherapyRisk ratio: 0.03, CI (0.00-0.20), P=0.0003DFS : resected dCRLM showed CPR vs no CPRHazard ratio: 0.40, CI (0.01-12.70), P=0.60OS : resected dCRLM showed CPR vs no CPRHazard ratio: 0.36, CI (0.03-4.12), P=0.41DFS: treated dCRLM vs dCRLM left in situHazard ratio: 0.72, CI (0.04-13.54), P=0.83 Open table in a new tab