Abnormal Hair Growth in Patients with Metastatic Colorectal Cancer Treated with the Anti-Epidermal Growth Factor Receptor Monoclonal Antibody Panitumumab

The study investigated abnormal hair growth in 24 patients with metastatic colorectal cancer treated with panitumumab, an anti-EGFr monoclonal antibody. It was found that 41.6% of patients developed hypertrichosis or trichomegaly, typically appearing on the cheeks, upper lip, and chin, within a median of 3.46 months after treatment initiation. No significant differences were observed in gender, race, or age between those who developed hypertrichosis and those who did not. The hair growth was not correlated with other skin toxicities or treatment regimens, but a higher response rate was noted in patients with hypertrichosis, linked to the duration of anti-tumor treatment. Further research was suggested to understand the underlying mechanisms of this side effect.