Effectiveness of prehepatectomy intra-arterial chemotherapy for multiple bilobar colorectal cancer metastases to the liver: a clinicopathologic study of peritumoral vasculobiliary invasion

BACKGROUND: Consensus remains to be achieved concerning prehepatectomy neoadjuvant chemotherapy as a treatment strategy for multiple bilobar colorectal liver metastases, in part because the effect of prehepatectomy neoadjuvant chemotherapy has not been determined pathologically. We investigated the efficacy of prehepatectomy intra-arterial chemotherapy for multiple bilobar colorectal cancer metastases to the liver. METHODS: Clinicopathologic data for 37 consecutive patients with > or =5 bilobar liver metastases from colorectal cancer who underwent hepatectomy were analyzed retrospectively with respect to long-term outcome and histological findings in resected liver tumors. RESULTS: In the 15 patients receiving neodadjuvant chemotherapy (NEO+ group), liver metastases progressed in 2 patients, remained stable in 8 patients, responded more than 50% in 4 patients, and responded completely in 1 patient (combined response rate, 33.3%). Overall and hepatic recurrence-free survival tended to be higher in responders than in nonresponders ( P = .053). Microscopic invasion of the portal vein, hepatic vein, and bile ducts near liver tumors was less frequent according to use of neoadjuvant chemotherapy and responsiveness to the therapy (responders, 20.0%; patients not receiving neoadjuvant therapy NEO-], 72.7%; P < .05). Such microscopic invasion independently predicted hepatic recurrence by multivariate analysis ( P = .011). CONCLUSIONS: A neoadjuvant chemotherapy-associated decrease in microscopic vasculobiliary invasion by metastatic liver tumors was related to clinical response and favorable outcome.