Impact of adjuvant immunotherapy in resected stage II/III/IV melanoma: A single center experience.

Abstract

e21565 Background: The incidence of malignant melanoma (MM) in Mediterranean countries is estimated at 3- 5/100.000 inhabitants/year with a predicted rising trend. MM is responsible for over 90% skin cancer deaths due to its tendency to metastasize early. Surgical excision is the treatment of choice for early-stage melanoma, however, 40-60% of patients with high recurrence risk melanoma, thick ulcerated primary melanomas (Stage IIC) and those with lymph node involvement (Stage III), experience a tumor relapse. Adjuvant therapy in resected high-risk melanomas has shown improved Relapse-Free-Survival (RFS), although no Overall Survival (OS) benefit has been observed to date. This retrospective observational study, conducted in one center, aims to evaluate effectiveness and safety of adjuvant therapies for resected high-risk melanoma. Methods: Single center cross-sectional study that included patients with a resected high-risk melanoma candidate for adjuvant treatment, at 2015-2022 period. Convenience sampling 48 patients recruited. Median follow up 55,4 months. Results: Median age was 54y, 52% were male and 93’6 is cutaneous melanoma. 53% were BRAF WT. Median Breslow (mm) was 3’85, median num/mm2 mitosis are 4 and 62’5% had ulceration. 15% presented satelosis or intransit metastasis and 55% had a lymphadenectomy. Melanoma stage: 9%IIB, 11%IIC, 11%IIIA, 25%IIIB, 38%IIIC, 2% IIID and 2% IV. Adjuvant treatment: 22% nivolumab, 20% ipilimumab+nivolumab, 12% ipilimumab, 16% interferon.75% of patients completed adjuvant treatment, 14% stopped for toxicity and 9% presented disease relapse (21% loca, 64% systemic). Best treatment response in relapse was 12% partial response, 37% progression. Toxicity: 18% presented grad ¾ toxicity. Efficacy: median RFS was 78’8m and median OS was NR. Conclusions: Adjuvant treatment is associated with an increased DFI in resected high risk melanoma patients. Adjuvant therapy was generally well tolerated, with manageable adverse events, consistent in type and incidence to those seen in clinical trials that allowed the approval for these compounds in adjuvant and metastatic scenarios. Prospective studies are needed to determine new biomarkers for the selection of those patients who could benefit to a greater extent from adjuvant therapies in resected high-risk melanoma.