Is Surgical Treatment Effective or Contraindicated in Patients with Colorectal Cancer Liver Metastases Exhibiting Extrahepatic Metastasis?

Surgical resection for patients with hepatic and extrahepatic colorectal metastases remains controversial. This study aimed to determine the efficacy of curative resection of distant extrahepatic metastatic lesions in patients with colorectal liver metastases (CRLM). From 2007 to 2019, 377 patients with CRLM were treated; of these, 323 patients underwent hepatectomy, and 54 patients with extrahepatic metastases (EHM) had received only chemotherapy. Survival and recurrence were compared between patients with and without EHM. Variables potentially associated with survival were analyzed in univariate and multivariate analyses. Among patients who underwent hepatectomy, the median, 3-, and 5-year overall survival rates for patients with EHM (n = 60) were 32 months, 47%, and 28%, respectively, while those for patients without EHM (n = 263) were 115 months, 79%, and 66%, respectively (p < 0.001). Furthermore, outcomes were similar in R2 patients with EHM and those with unresectable tumors. However, outcomes were significantly better in the R0/1 group than in the R2 and unresectable groups (p < 0.001). Among patients with EHM, multivariate analysis revealed that higher clinical risk score, incomplete resection of all EHM, extrahepatic disease detected intraoperatively, and previous treatment with neoadjuvant chemotherapy were independently associated with worse survival. In patients with CRLM with EHM (liver + one organ), gross curative resection is necessary when surgical treatment is contemplated, and resection of liver metastases should be performed in patients with CRLM with smaller and fewer tumors (e.g., H1).