Study of Skin Toxicity of Cetuximab: Find a Link Between Skin Inflammation and Tumor Response

Colon cancer is one of the most common cancers in France with more than 36,000 new cases per year. Despite significant advances in therapeutic care, the prognosis of colon cancers with metastases remains bad. The treatment of metastatic disease is based on chemotherapy coupled with therapeutic antibodies. The most commonly used are anti-EGFR (Epidermal Growth Factor Receptor), which allowed a significant increase in patient survival. They are responsible for skin toxicity in the form of an acneiform rash which can be debilitating for patients and require discontinuation of treatment. However, this toxicity is strongly correlated with treatment efficacy. Understanding the mechanisms of cutaneous side effects of anti-EGFR is therefore a major challenge to treat and better understand the association with treatment efficacy. The objective of this study is to investigate a link between cutaneous inflammatory response in patients treated with anti-EGFR, serum level of anti-EGFR and treatment efficacy. It will be conducted systematic consultations dermatology, skin biopsies and blood samples in patients treated with anti-EGFR. From biopsies, it will be searched by an infiltration of inflammatory cells and expression of genes involved in skin inflammation.