Response rates to hepatic arterial infusion (HAI) pump therapy in patients with metastatic colorectal cancer liver metastases (mCRC LM) after progression on all standard chemotherapies.

Abstract

597 Background: To evaluate the overall response rate of HAI with floxuridine (FUDR) in the refractory setting in patients with mCRC LM. Methods: After obtaining an IRB waiver a computerized search was performed for patients with mCRC treated with 5FU, oxaliplatin and irinotecan +/- EGFR and VEGF inhibitor from 2003-2012. Charts were reviewed to ensure patients (pts) had received all standard therapies prior to HAI pump placement. All pts received HAI FUDR and no new systemic targeted or cytotoxic therapies were used with HAI pump. Imaging was re-reviewed for confirmation of progression prior to HAI pump placement and for best response using RECIST 1.1 criteria. Results: 75 pts were identified; of these 23 had radiographic disease progression on all standard chemotherapies (5FU, irinotecan and oxaliplatin) prior to having a pump placed. Of the 23 evaluable pts, the median age was 53 (range 37-75). Six pts had low volume extrahepatic metastases at the time of pump placement. The overall response rate (ORR) was 8/23 (35%); 10/23 (43%) pts had stable disease (SD). The median duration of SD was 4 months (range 1-10). Median follow up, measured from the date of HAI initiation, was 24 months and median overall survival (OS) was 22 months (95% CI 13-16). The median hepatic progression free survival (hPFS) was 4.5 months [CI: 3.8-6.7]. Thirteen pts developed extrahepatic disease progression (including 5 pts with preexisting extrahepatic disease). The median overall PFS was 3.9 months [95% CI 2.24-5.33]. Median number of HAI treatments was 4 cycles (range 1-13). Six out of 23 (26%) pts required a 50-75% dose reduction by the second cycle due to elevated liver function tests and 18/23 (78%) required a dose reduction after the 3rd cycle. No pts required stents or developed long term liver or biliary toxicity. Conclusions: In a cohort of 23 patients with mCRC LM, refractory to all standard agents, treatment with HAI FUDR resulted in an ORR by RECIST 1.1 of 35% and median OS of 22 months. Further studies focusing on locoregional therapy in patients with liver predominant disease are warranted. Studies to molecularly characterize these tumors are ongoing.