Effects of Type of Antibody to EGFR and Hypomagnesemia on Overall Survival in First-line Treatment of Patients With Unresectable Advanced/Recurrent Colorectal Cancer.

AIM To clarify the differences in overall survival (OS) depending on the presence or absence of hypomagnesemia and the type of epidermal growth factor receptor antibody as first-line therapy for metastatic colorectal cancer (mCRC). PATIENTS AND METHODS We retrospectively compared the OS in 68 patients who received cetuximab or panitumumab for mCRC at Ogaki Municipal Hospital (Ogaki, Japan) between January 2010 and December 2019. RESULTS The complete and partial response rates in the cetuximab and panitumumab groups were 60.0% and 72.0%, respectively (p=0.470). The OS was significantly longer in the panitumumab group (median=1,007 days, range=208-1,433 days) than in the cetuximab group (median=735 days, range=181-2,391 days; p=0.047). Hypomagnesemia did not contribute to differences in OS in the two groups. CONCLUSION Panitumumab may lead to a longer OS than cetuximab as first-line treatment of mCRC. The presence or absence of hypomagnesemia in cetuximab- or panitumumab-treated patients did not affect OS.