Association of bevacizumab-free interval with efficacy of anti-EGFR therapy in patients with metastatic colorectal cancer

• Published in: Journal of clinical oncology Vol. 32; no. 3_suppl; p. 610
• Main Authors: Komori, Azusa, Taniguchi, Hiroya, Narita, Yukiya, Uegaki, Shiori, Nitta, Sohhei, Yamaguchi, Kazuhisa, Nomura, Motoo, Kadowaki, Shigenori, Takahari, Daisuke, Ura, Takashi, Andoh, Masashi, Muro, Kei
• Format: Journal Article
• Language: English
• Published: 20.01.2014
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/jco.2014.32.3_suppl.610

Abstract only 610 Background: Both bevacizumab (Bev) and anti-EGFR agents are sequentially used for metastatic colorectal cancer (mCRC). Some basic studies reported the interaction between Bev and anti-EGFR agents in vivo. Therefore we hypothesized the shorter Bev-free interval may lead to poor outcome of anti-EGFR therapy. The aim of this study is to examine the association of the interval between last Bev administration and initial anti-EGFR agents with efficacy of anti-EGFR therapy. Methods: We retrospectively reviewed consecutive mCRC patients who underwent combination therapy of anti-EGFR agents and irinotecan after failure of fluoropyrimidines, oxaliplatin, irinotecan, and Bev at a single institution. We divided patients in two groups (group A: the interval between Bev and anti-EGFR agents <6M, group B: ≥6M). Results: A total of 114 patients constituted the cohort of analysis. The median age was 63; 78 (68%) patients were male. Most patients (N=100, 88%) were treated with cetuximab, and 14 patients were panitumumab. Seventy-four patients were group A and 40 patients group B, respectively. There was no significant difference in patient characteristics. Response rate was 24.7% in group A, and 50.0% in group B (p=0.0072). The patients in group B have significantly longer progression free survival (4.2 vs. 6.6 M, HR 0.65, 95% CI 0.43- 0.98, p=0.042) and longer overall survival (11.6 vs. 14.3 M, HR 0.62, 95% CI 0.39- 0.97, p=0.038). Conclusions: The short interval (<6M) between last Bev and anti-EGFR agents may interfere with the efficacy of anti-EGFR therapy.