177P Radiologic feature after chemotherapy with anti-VEGF drug for CLM

Abstract

Aim/Background: It was reported that novel criteria based on morphologic changes observed on computed tomography in patients with colorectal liver metastasies (CLM) undergoing preoperative chemotherapy and long-term outcomes. The purposes of this study were to confirm the difference of morphologic change to CLM after various chemotherapies. Methods: The study included 38 patients who underwent 5FU-based 1st line regimens with or without molecular target therapy (anti-VEGF drug or anti-EGFR drug) for CLM from 2007 to 2012. They were divided into 3 groups (12 cytotoxic agents alone group, e.g. FOLFOX, XELOX and FOLFIRI, 17 cytotoxic agents with anti-VEGF drug group, and 9 cytotoxic agents with anti-EGFR drug group) retrospectively. All patients underwent routine contrast-enhanced CT at the start of and during chemotherapy. We created a circle to assume 1/4 of the minor axis a radius from the center of a liver tumor, and measured a circular inside CT value of the tumor and an outside CT value and revised the value of erector spinae muscle in a standard. We defined revised inside CT value as Tin, and outside as Tout. Assessment was performed using RECIST. Results: The rate of response in each group was 33.3%, 58.8%, 66.7%. Two of these 38 patients had a complete response. In comparison with CT before the treatment and the CT 12 weeks after the treatment, eight of 9 responder with anti-VEGF drug showed that the Tin decreased more than 30%, whereas none of 7 non responder with anti-VEGF drug didn't show similar morphologic change (p = 0.0014). The morphologic change that the Tin decreased more than 30% was observed in 88.9 % of response patients with anti-VEGF drug, 25.0% of response patients with cytotoxic agents alone, and 40.0% of response patients with anti-EGFR drug. Though there was no statistically significant difference among the three groups (p = 0.06), these results may in part explain the radiologic feature after chemotherapy with anti-VEGF drug for CLM. Conclusions: Liver tumor after chemotherapy with anti-VEGF drug may do different morphologic change from the other chemotherapy. Disclosure: All authors have declared no conflicts of interest.