Impact of metabolic liver disease on colorectal cancer and liver metastases: Pathophysiology and implications for hepatobiliary surgery

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing globally and affects a growing proportion of patients with colorectal cancer (CRC). Beyond shared risk factors such as obesity and metabolic syndrome, MASLD appears to actively shape a pro-metastatic hepatic microenvironment, with important implications for colorectal liver metastases (CRLM), particularly in the surgical setting. Methods: This narrative review synthesizes epidemiologic, mechanistic, imaging, and clinical data on the interplay between MASLD and CRC/CRLM, with a focus on hepatobiliary surgical relevance. Results: MASLD is associated with increased risks of colorectal adenomas and CRC. Key mechanisms contributing to a pro-metastatic hepatic niche include insulin resistance, adipokine dysregulation, gut-liver endotoxemia with TLR4/NF-kappa B activation, chronic inflammation, fibrosis and extracellular matrix remodeling, and oxidative stress. Clinically, steatohepatitis and fibrosis are linked to higher perioperative morbidity, postoperative liver failure, and worse short-term outcomes after hepatectomy, whereas simple steatosis shows heterogeneous associations with survival. Chemotherapy-associated liver injury frequently overlaps with MASLD. In addition, MASLD reduces CT sensitivity for small hepatic lesions, while abbreviated non-contrast MRI improves surveillance. Conclusions: MASLD is a clinically relevant modifier of CRLM biology and surgical risk. Early identification, metabolic optimization, MASLD-informed perioperative planning, and MRI-based surveillance should be prioritized. Prospective phenotype-resolved studies are needed to refine risk stratification.