Key clinical point: Efficacy of antiepidermal growth factor receptor (EGFR) for treating metastatic colorectal cancer (CRC) differs with primary tumor location, with efficacy being higher with metastatic left-sided colon cancer than with middle/low rectal cancer.
Major finding: Among patients undergoing the first-line anti-EGFR therapy, those with left-sided vsvs middle/low rectal tumor had significantly higher progression-free survival (hazard ratio [HR], 0.67; P = .007), overall survival (HR, 0.62; P = .008), and overall response rate ( P = .002). Findings were similar with nonfirst-line anti-EGFR treatment.
Study details: Findings are from a retrospective cohort study of 609 patients with metastatic CRC who were treated with anti-EGFR therapy. Based on primary tumor location, patients were classified into right-sided colon (n=125), left-sided colon (n=313), and the middle/low rectal (n=171) groups.
Disclosures: The study was supported by grants from the Ministry of Science and Technology, Taiwan; Taipei Veterans General Hospital; and the Taiwan Clinical Oncology Research Foundation. The authors declared no competing interests.
Source: Lee KH et al. Br J Cancer. 2021 Jun 29. doi: 10.1038/s41416-021-01470-2 .