Association Between Helioderma and Response to Immunotherapy in Patients With Metastatic Melanoma

The detection and management of melanomas must be very early because the prognosis largely depends on the extent of the disease at the time of diagnosis. For patients with melanoma, immunotherapy or dual therapy is used as treatment in unresectable and metastatic (AJCC stage IV) cases, depending on mutation status. Primary immunotherapy is possible in mutated patients in the absence of threatening progression. However, not all patients respond well to immunotherapy, so biomarkers that predict treatment response are needed to optimize patient benefit. The onset, development, and course of melanoma are based on the accumulation of genomic changes, including high loads of ultraviolet-induced mutations, which make melanoma the most immunogenic tumor. In several tumor types, tumor mutation load (TMB) and immune infiltration have been reported to predict response to immunotherapy. Indeed, the higher the TMB, the more the tumor is likely to produce a neo-tumor antigen, target of the reactivation of the immune system. No threshold value of TMB has been determined to date, having a predictive value in melanoma. The degree of helioderma could be a potentially discriminating marker of the degree of UV exposure and therefore of mutagenesis. Preliminary results have reported the interest of this approach but must be confirmed because it was a small study (Russo et al). UV-induced DNA damage results in clinical signs of heliodermia or photoaging: more or less deep wrinkles, loss of elasticity, thinning of the skin, lentigo pigmentary disorders, yellowish color of the skin, telangiectasias, on the skin areas exhibited. Helioderma could therefore be an easily accessible clinical predictor of a good response to immunotherapy. The aim of the study is to study association between helioderma and response to immunotherapy in patients with metastatic melanoma.