Clinical Characteristics and Impact on Prognosis of Melanoma Accompanied by Multiple Primary Malignancies: A Retrospective Analysis.

Introduction: This study aims to explore the clinical characteristics and prognosis of patients with melanoma (MM), which are composed mainly of acral and mucosal MM accompanied by multiple primary tumors.

Methods: A total of 87 patients diagnosed with single primary MM and 87 patients diagnosed with multiple primary malignant tumors were included. Nonmelanoma malignancy tumor type, genetic testing, and the survival data were collected. Pearson's chi-square test, Fisher's exact test, log-rank test, univariate and multivariate Cox's regression analysis were applied.

Results: The most common nonmelanoma malignancies in all patients involved the digestive system; breast cancer, thyroid cancer, lung cancer, and prostate cancer; and breast cancer was more common in patients with acral MM. Mutations in BRAF V600, NRAS, KIT, and TP53 were the most common. Univariate analysis revealed that mutations in KIT and elevated levels of lactate dehydrogenase (LDH) were potential factors that influenced OS. Multivariate analysis revealed that mutations in NRAS and increased LDH levels were related to worse survival and that survival was prolonged in patients with MM as the first primary tumor.

Conclusion: This study preliminarily describes the clinical features and prognosis of patients with melanomas, while the further study with larger sample size is needed.