Adjuvant immunotherapy in high-risk stage II melanoma: real-world outcomes from a large multicenter retrospective study

Background: Cutaneous melanoma (CM) is an aggressive cancer since early stages. Stage IIB/C CM present significant recurrence risk. Recently, adjuvant immunotherapy demonstrated to increase recurrence-free survival (RFS) in this setting. Objective: Assess safety and efficacy of adjuvant immunotherapy for stage IIB/C CM in a real-world setting. Methods: Stage IIB/C CM patients treated with adjuvant immunotherapy in eight centers from the "Gruppo Oncologico Italia Meridionale" (GOIM) were retrospectively investigated. Data were collected over a median follow-up of 16 months. Results: Ninety-six patients with a median age of 59 years were included. Most participants were male (64.6%). Approximately 60.4% were classified stage IIB and 39.6% stage IIC, with the majority of tumors localized on the trunk (54.2%). Toxicity occurred in 63.5% of patients with 79.7% of these events classified as grade 1-2 (CTCAE v5.0). The most reported events were thyroid dysfunction, fatigue, gastrointestinal disorders and itchiness. Recurrence was observed only in 7 patients (7.3%). Conclusions: The 12-month and 24-month RFS were respectively 98.7% and 82.6%. The toxicity profile was generally manageable in a real-life population, however 17.6% of all patients experienced grade 3-4 AEs, underscoring the importance of evaluating adjuvant therapy in a multidisciplinary setting.