Retrospective Analysis of Skin Toxicity in Patients under Anti-EGFR Tyrosine Kinase Inhibitors: Our Experience in Lung Cancer.

Background: Tyrosine kinase inhibitors (TKIs) have been introduced for the treatment of lung cancer, improving progression-free survival, objective response rate, and quality of life. However, TKIs can lead to cutaneous toxicities, including papulopustular rash, xerosis, paronychia with/without pyogenic granulomas, scalp disorders, facial hair and/or eyelash growth.

Aim: In this study, we describe retrospectively all cases of mucocutaneous side effects in patients with lung cancer under TKIs referring to our outpatient for the skin care of oncological patients.

Methods: We included patients referring from January 2016 to January 2018 affected by lung cancer and under TKIs. We collected data about the clinical exam, clinical photography, dermoscopy, histology and direct microscopic examination for each patient and we performed retrospectively descriptive analyses to assess whether a specific TKIs is linked significantly to particular cutaneous toxicity.

Results: The majority of skin toxicities were due to afatinib, and the most common skin reaction was rash. We selected 60 patients with skin reactions, treated by TKIs for lung cancer. The majority of skin toxicities were due to afatinib (47/102 adverse reactions) and erlotinib (39/102). The most common skin reaction was rash (63% of patients), followed by xerosis (30%) and granulomas (30%). There was no significant relationship between a specific type of cutaneous reaction and specific EGFRi except for granulomas, developed more frequently in patients under afatinib (p < 0.05).

Conclusion: Most of our patients (63%) developed a cutaneous rash under TKIs. Most commonly afatinib was the drug involved, although it wasn't the most used EGFRi. Moreover, we noticed a significant correlation between afatinib therapy and appearance of granulomas.