Generation of an Artificial Intelligence Algorithm Based on the Analysis of Melanoma Peri-scar Dermatoheliosis, as a Predictive Factor of Response to Anti-PD-1

Inclusion Criteria: ▪ Adult patients with inoperable stage III or IV melanoma, or inoperable skin carcinoma (squamous cell carcinoma or basal cell carcinoma). Retrospective cohort: patients who have received curative treatment with anti-PD1, +/- anti-CTLA-4 or anti-LAG-3 for their skin cancer for at least 90 days, with at least 6 months of follow-up, without immunosuppression and whose primary tumour site is not altered by concomitant dermatosis. Adjuvant immunotherapy is tolerated if it was stopped at least 6 months before the start of curative treatment. Interferon is also tolerated if it was stopped at least 6 months before the start of curative treatment. Radiotherapy is tolerated if it did not take place at the site of the primary melanoma scar. For squamous cell carcinomas, prior radiotherapy on the scar is acceptable (it must simply not have been administered during the period of anti-PD-1 treatment in order to be able to reliably assess the response). Inoperable primary tumours are eligible. Targeted therapy is accepted before the start of curative treatment with immunotherapy. Chemotherapy is not accepted prior to the initiation of curative treatment with immunotherapy. ▪ Prospective cohort: Patients who have not received immunotherapy for the management of their skin cancer at the start of curative treatment with anti-PD-1, +/- anti-CTLA-4 or anti-LAG-3. Adjuvant immunotherapy is tolerated if it has been discontinued for at least 6 months prior to the start of curative treatment. Interferon is also tolerated if it has been discontinued for at least 6 months prior to the start of curative treatment. Radiotherapy is tolerated if it has not been administered at the site of the primary cancer scar. Targeted therapy is accepted before starting curative treatment with anti-PD-1, +/- anti-CTLA-4 or anti-LAG-3. Chemotherapy is not accepted before the start of curative treatment with anti-PD-1, +/- anti-CTLA-4 or anti-LAG-3. ▪ Patients who have agreed to participate in the research and have signed an image rights authorisation form. Exclusion criteria: * Retrospective cohort: Patients who have received curative treatment with anti-PD-1, +/- anti-CTLA-4 or anti-LAG-3 for skin cancer for less than 90 days * Patients who received adjuvant immunotherapy within 6 months prior to curative treatment * Patients who received chemotherapy prior to curative treatment * Patients whose primary skin cancer site cannot be photographed (e.g. choroidal melanomas, mucosal melanomas, with the exception of vulvar or penile melanomas, etc.). * Patients treated with systemic corticosteroids (dose greater than 10 mg/day) at the start of the immunotherapy in question, * Patients who are immunocompromised (associated blood disorder, human immunodeficiency virus infection, transplant patients, etc.) at the start of immunotherapy, * Patients with iatrogenic peri-scar vitiligo, * Patients who have refused to participate in the research, * Adults protected by law.