Identification of patients who most benefit from hepatic arterial infusion (HAI) combined or not with systemic chemotherapy for the treatment of unresectable colorectal liver metastases

14565 Background: Although locoregional treatments such as hepatic arterial infusion (HAI) claim the advantage of delivering higher doses of anticancer agents directly into the affected organ, there is substantial lack of evidence for benefit in terms of overall survival (OS). To test the hypothesis that systemic chemotherapy affects OS of patients with unresectable colorectal liver metastases treated with HAI. Furthermore, we investigated patient- and tumor-related predictive factors that might identify patients who most benefit from HAI regimen. Methods: In this retrospective study, 153 consecutive patients treated at our institution were considered. In group-A (n=72), patients were treated with HAI alone (floxuridine (FUDR) 0.2 mg/Kg + leucovorin (LV) 4 mg/m2 + desamethasone 20 mg 14 days/month) between 1994 and 1999. In group-B (n=81), patients were treated with the same HAI regimen combined with systemic chemotherapy (5-fluorouracil (5FU) 450 mg/m2 + LV 20 mg/m2) between 1999 and 2003. Results: No difference in OS was observed between group-A and group-B (median OS: 18.0 and 19.1 months, respectively). Considering all patients (group A + group B), low tumor load was associated with a better tumor response rate, but none of the traditional clinico-pathological prognostic factors correlated with OS. Median OS was better in patients with less than 50% of liver parenchyma involvement (21.3 vs 13.2 months; P<0.0001) as well as in responders (complete or partial response) versus non-responders (24.4 vs 13.4 months; P<0.0001). The combination of low tumor load with good tumor response to HAI was the only variable retained at multivariate analysis, and identified a subgroup of patients with a very favorable clinical outcome (median survival: 34.2 months; hazard ratio: 0.347, CI: 0.249–0.564, P< 0.0001). Conclusions: Combination with 5FU+LV systemic chemotherapy did not lead to an OS benefit over FUDR-based HAI alone. The identification of tumor response predictors is urgently needed, as it would lead to the tailored treatment of patients with low load but unresectable metastatic liver disease who most benefit from HAI therapy. No significant financial relationships to disclose.