Dermatological side effects of immunotherapy drugs and targeted cancer therapies: Importance of dermatology and oncology collaboration.

Introduction: Novel anti-cancer drugs such as targeted cancer therapies and immune check-point inhibitors (ICIs) have adverse events, especially concerning the skin. The aim of this study is to report an overview of the commonly consulted dermatological side effects of ICIs and targeted cancer therapies in clinical practice, along with their management.

Methods: In this single-center study, we evaluated consecutive oncological patients who were referred from the oncology outpatient clinic to the dermatology outpatient clinic due to skin side effects of ICIs and targeted therapies. All patients were examined and treated at the same day of referral by experienced dermatologists. Patient characteristics, clinical findings, diagnostic workups and treatments were retrieved from outpatient records.

Results: Sixty three patients were enrolled. Most common diagnoses were lung carcinoma, melanoma and colon carcinoma. Fifty patients (79%) were using targeted therapies while 13 (21%) were using ICIs. Xerosis was the most common side effect (44%), followed by acneiform rash, paronychia, eczema and pruritus. Majority of the side effects were grade 2 and 3. Psoriasis was a common side effect of ICIs. One patient had a newly developed dysplastic nevus on vemurafenib treatment. Oncological treatment was not withheld in any of the patients.

Conclusions: This study revealed the most commonly consulted skin side effects of novel anti-cancer drugs and their management in daily practice. We underlie the importance of collaborative work of oncology and dermatology professionals as early management of cutaneous side effects of targeted therapies and ICIs improves patient outcomes.