Incidence, Outcomes and Predictors of Primary Central Nervous System Melanoma: A SEER-Based Study

Abstract

Primary central nervous system (pCNS) melanoma is an extremely rare malignant tumor. We explored the incidence, outcomes, and predictors of pCNS melanoma. We queried the Surveillance, Epidemiology, and End Results database to identify all patients diagnosed with pCNS melanoma during 1973-2015. Overall survival (OS) was obtained by using the Kaplan-Meier curves. Log-rank test was used to compare survival across groups of age, sex, race, tumor location, size, surgical resection, radiotherapy, chemotherapy and year of diagnosis. Cox regression was used for univariate and multivariate analysis of survival. A total of 84 pCNS melanomas were identified with a 5-year OS of 37.7%. The overall age-adjusted incidence rate was 0.52 per 10,000,000 person-years. Age ≤19 years (vs. age 20-59 years, hazard ratio [HR]= 2.37, 95% confidence interval [CI]: 1.11-5.07, P= 0.03) and intracranial location (vs. intraspinal, HR= 1.98, 95% CI: 1.04-3.77, P= 0.04) were associated with decreased survival rate. Gross total resection surgery (vs. partial resection, HR= 0.31, 95% CI: 0.15-0.66, P= 0.002) was associated with improved survival rate. There was no significant association between other demographic characteristics, tumor size, therapy methods, year of diagnosis, and OS. The overall age-adjusted incidence rate of pCNS melanoma is 0.52 per 10,000,000 person-years. Age ≤19 years and intracranial tumor location are independent risk factors of low survival rate, whereas gross total resection is associated with better survival rate.