Management of Colorectal Cancer with Synchronous Liver Metastases: A systematic review of national and International Clinical Guidelines (CoSMIC-G)

Introduction: The contemporary management of patients with colorectal cancer and synchronous liver metastases is complex. This study appraises the recommendations made by national/international guidelines for the diagnosis and management of patients with synchronous liver metastases from colorectal cancer. Methods: A systematic review of national and international guidelines published between 2011 and 2024 was carried out using PubMed, OvidSP and Guidelines International Network databases. The quality of guidelines was evaluated using the Appraisal of Guidelines for Research & Evaluation II (AGREE II) instrument. Guidelines were assessed for the quality of advice for specific scenarios. The protocol was registered with PROSPERO (CRD42021243744). Results: The search strategy returned ninety unique articles with 11 guidelines eligible for inclusion. Of these, one (9 %) guideline defined 'synchronous disease' at outset, eight (73 %) recommended neoadjuvant chemotherapy as first intervention. Seven (64 %) guidelines supported synchronous hepatic resection with colectomy. One (9 %) recommended against synchronous surgery. Conclusions: This study demonstrates important variations between international clinical guidelines on diagnostic workup and management of synchronous liver metastases in colorectal cancer. [167 words].