Racial/ethnic disparities and incidence of malignant peripheral nerve sheath tumors: results from the Surveillance, Epidemiology, and End Results Program, 2000-2014

Background: Malignant peripheral nerve sheath tumors (MPNSTs) are rare tumors, generally high-grade, and comprise ~ 5-10% of soft tissue sarcomas. Over two-thirds of MPNSTs metastasize, and upwards of 40% clinically recur. Etiologic risk factors for MPNSTs are historically understudied. There is evidence to suggest MPNST incidence differs across racial/ethnic groups in pediatric populations. Therefore, we sought to estimate differences in MPNST incidence by race/ethnicity among all ages in the United States.

Methods: Incidence data were obtained from the Surveillance, Epidemiology, and End Results (SEER-18) Program, 2000-2014. Race/ethnicity was categorized as: White; Black; Asian; Other; and Latino/a ("Spanish-Hispanic-Latino"). Latino/a included all races, while all other categories excluded those identified as Latino/a. Age-adjusted incidence rate ratios (IRR) and 95% confidence intervals (CIs) were generated in SEER-STAT (v8.3.4). We estimated incidence rates among all ages, and among those diagnosed < 25 and ≥ 25 years.

Results: MPNST cases were abstracted from SEER-18 (n = 1047). Among all age groups, Blacks experienced an elevated incidence of MPNSTs compared to Whites (IRR_Blacks = 1.26, 95% CI 1.04-1.50). Asian and Latinos/as experienced lower incidences compared to Whites (IRR_Asians = 0.78, 95% CI 0.61-0.99; IRR_Latinos/as = 0.84, 95% CI 0.69-1.02). In subgroup analyses, no statistically significant associations with MPNSTs were identified among cases diagnosed < 25 years of age, whereas the associations observed among all age groups were prominent among those diagnosed ≥ 25 years of age.

Conclusions: Incidence rates of MPNSTs were highest in Blacks compared to Whites and other minority groups. This study suggests specific patterns exist in terms of race/ethnicity and age at diagnosis of MPNSTs.