Local and disease control for nasal melanoma treated with radiation and concomitant anti‐programmed death 1 antibody

Mucosal melanoma of the nasal cavity is a rare disease that has been consistently associated with poor outcome. While complete surgical excision offers the only prospect of a cure, it is associated with a high risk of surgical morbidity due to the challenging anatomical location, and most patients still develop incurable metastatic disease. The efficacy of immunotherapy on mucosal melanoma is lower in comparison with cutaneous melanoma, and mucosal melanoma rarely has BRAF mutations. Although preclinical data have shown that combination treatment with immune checkpoint inhibitors and radiotherapy (RT) improve the response, there have been few reports on the combination of RT and anti‐programmed death 1 therapy for mucosal melanoma of the nasal cavity. We retrospectively investigated 10 cases of mucosal melanoma of the nasal cavity in which combined treatment was applied. The local control (LC) rate of the primary lesion and regional lymph nodes was favorably 100%. On the other hand, the median progression‐free survival (PFS) time was 29.6 weeks (range, 2–82). The 6‐month PFS rate was 60%. Although severe mucositis occurred in one patient, the incidence of treatment‐related adverse events was not significantly increased. RT with anti‐programmed death 1 antibody therapy for mucosal melanoma of the nasal cavity was tolerable and had the potential to improve LC and PFS.