Observational cohort study focused on treatment continuity of patients (pts) treated with XELOX plus bevacizumab (BV) for previously untreated metastatic colorectal cancer (mCRC).

Abstract

661 Background: Systemic chemotherapy for unresectable mCRC has remarkably progressed as a results of wide spread use of irinotecan, oxaliplatin, anti-VEGF antibody and anti-EGFR antibody. It is important to continue treatment combined with these drugs and prolong progression-free survival so as to improve overall survival. Methods: We planned and conducted the prospective observational cohort study of 40 pts treated with XELOX + BV for previously untreated mCRC to investigate the treatment continuity of XELOX + BV. Endpoints were time to treatment-failure (TTF), overall response rate, resection rate, liver resection rate, progression-free survival (PFS), overall survival (OS) and safety. Eligibility criteria were (1) histologically confirmed mCRC, (2) with lesions evaluable by imaging, (3) previously untreated (except for surgery), (4) with condition enough to receive XELOX + BV, (5) written informed consent. Forty pts were planned to be enrolled during 2 years and followed up to 2 years. Results: Between July 2010 and June 2012, 40 pts were enrolled. Baseline characteristics were the following; male/female 24/16, median age 63 yrs (range 35-84 yrs), ECOG PS 0/1/2 33/6/1, primary cite colon/rectum 24/16, primary resection prior XELOX+BV yes/no 35/5, metastatic cite liver/lung/paraaorta/peritoneal/local recurrence/others 23/16/4/7/3/4, the number of metastatic cite 1/2/3 26/9/5.The median TTF was 5.3 months (95%CI: 3.6 – 9.1 months), and the reasons for treatment discontinuation were the following; CR 4 pts, resection 10 pts, progression 12 pts, adverse events 7 pts and pts refusal 3 pts. Four pts continued their treatments.The overall response rate was 52.5% (CR 6 pts and PR 15 pts), resection rate was 25.0% (liver 6 pts, lung 2 pts and primary 2 pts), and liver resection rate was 15.0%. The median PFS was 13.3 months (95%CI: 9.8 months – NR) and the median OS was not reached. Conclusions: Although the median TTF was 5.3 months, the median PFS was prolonged to 13.6 months. This might result from chemo-free interval caused by 4 pts’ CR and 9 pts’ resections. We will further investigate 40 pts’ 2-year survival data. Clinical trial information: UMIN000003416.