Comparison of Side Effects of Anti-epidermal Growth Factor Receptor (Anti-EGFR) Antibody Drugs During Initial Induction and Reinduction in Colorectal Cancer: A Case Series.

Anti-epidermal growth factor receptor (anti-EGFR) antibodies are used to treat colorectal cancer. The incidence of side effects is higher in patients who receive re-administration than in those who were initially introduced. In this report, we describe three cases. Case 1 involved a woman in her 70s. Compared with the initial administration, skin rash, skin dryness, and stomatitis grades were observed to be high. Finally, the patient was diagnosed with progressive disease (PD) after five months, which was shorter than that at the time of initial administration. Case 2 involved a man in his 70s, who was restarted on panitumumab monotherapy. Approximately one month after re-administration, the patient developed early grade 3 skin symptoms and hypomagnesemia, peaking at 0.8 mg/dL. Finally, the patient was diagnosed with PD after approximately six months, which was shorter than that at the time of initial administration. Case 3 involved a man in his 30s. After resuming the same treatment, the patient developed paronychia up to grade 3, which continued for approximately two years with dermatological intervention. In the ambulatory therapy center, multi-disciplinary medical staff are involved in the prevention of serious complications. Early intervention and patient education regarding the adverse effects connected with re-administration are essential.