RESUMEN
To compare the efficacy and safety of cetuximab biweekly regimen with those of standard weekly regimen as a first-line therapy of KRAS/RAS wild-type metastatic colorectal cancer. Methods: Patients who received weekly or biweekly administra-tion of cetuximab plus FOLFOX/XELOX as a first-line therapy from July 2010 to December 2017 in Cancer Hospital, Chinese Academy of Medical Sciences were retrospectively screened for eligibility. Objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and frequencies of adverse events (AEs) between the two groups were compared. Results: Of 152 eligible patients, 55 were in the biweekly group and 43 were in the weekly group. The biweekly group had significantly higher ORR than the weekly group (76.3% vs. 54.8%, P=0.025). Median PFS in the biweekly and weekly groups were 10.3 and 8.8 months, respectively (P=0.288), and the median OS were 33.5 and 27.4 months, respectively (P=0.563). The two groups showed no significant difference in PFS and OS. For overall AEs, the biweekly group presented significantly more stomatitis (32.7% vs. 14.0% , P=0.032) and tended to show substantially more acne-like rash (80.0% vs. 62.8%, P=0.058) and leukopenia and/or neutropenia (72.7% vs. 55.8%, P=0.081). The frequency of 3/4 grade acne-like rash in the biweekly and weekly groups were 18.2% and 7.0%, respectively (P=0.105). The frequency of all grade 3/4 AEs between the two groups showed no significant difference (P>0.05). Conclusions: Biweekly regimen of cetuximab plus FOLFOX/XE-LOX had similar efficacy and higher ORR compared with those of standard weekly regimen. Cetuximab administered biweekly may be an optional choice in clinical practice, with close attention paid to increased frequency of certain AEs.