Background/aims: Hepatic resection is one of the most effective therapies for colorectal liver metastasis. However, extrahepatic metastasis is frequently encountered within a short time postoperatively. We attempted to clarify the risk factors for extrahepatic metastasis in patients with colorectal liver metastasis.
Methodology: We retrospectively analyzed data obtained from 116 consecutive patients with colorectal liver metastasis. To determine predictors of extrahepatic metastasis within 1 year of admission for treatment of colorectal liver, we examined 12 clinicopathologic factors by univariate and multivariate logistic regression analyses.
Results: Eighty-five underwent hepatectomy and/or thermal ablation (hepatectomy group) and 31 underwent only chemotherapy (non-hepatectomy group). Thirty-one in the hepatectomy group and 19 in the non-hepatectomy group developed extrahepatic metastasis at 1 year after admission. Univariate analysis showed that treatment without hepatectomy and lymphatic vessel permeation at the primary site were significant predictive factors for extrahepatic metastasis within 1 year. Multivariate analysis showed lymphatic permeation of the primary tumor, and treatment without hepatectomy to be significantly related to the occurrence of extrahepatic metastasis within 1 year.
Conclusions: The two factors that we identified put patients with colorectal liver metastasis at high risk for extrahepatic metastasis. Systemic chemotherapy may be needed to prevent extrahepatic disease in such patients.