TOXICAN: a guide for grading dermatological adverse events of cancer treatments.

Purpose: The dermatological toxicity of cancer treatments is frequent and sometimes debilitating. Its reference classification, the NCI-CTCAE (National Cancer Institute-Common Terminology Criteria for Adverse Events), is sometimes difficult to use and does not include yet the newest toxicities. Our objective was to create a guide, TOXICAN, based on the CTCAE, which is easy to use in everyday practice and which facilitates the recognition and grading of these dermatological toxicities.

Methods: This guide was developed by a working group ("GESTIM") comprising oncodermatologists, allergists, pathologists, and researchers from Nantes University Hospital. It was based on the dermatological toxicities found in the CTCAE and adapted to daily practice. These toxicities were grouped into categories and associated with photographs of typical cases to aid recognition. A simplified grading scale derived from the CTCAE was also created. This booklet was validated by means of user evaluation, and then the Delphi consensus method.

Results: We selected 32 dermatological toxicities, including 12 created by our group, sorted into 7 categories: skin rash, dry skin/pruritus, hyperkeratotic papules, palmoplantar changes, hair and nail changes, mucosal changes, and others. Our simplified grading scale only differed from the CTCAE for one item, urticaria. Three items were modified after evaluation by the user group and 11 after application of the Delphi method.

Conclusion: The objective of our practical guide is to facilitate the use of the CTCAE for recognizing and grading dermatological toxicity of cancer treatments in order to provide optimal guidance for therapeutic adaptations. Its impact on clinical practice remains to be evaluated.