Malignant peripheral nerve sheath tumors: Analysis of the national cancer database

Objectives: Malignant peripheral nerve sheath tumor (MPNST) is a rare type of soft tissue sarcoma (STS) that carries significant mortality. Given the rarity of MPNST, current knowledge on the disease is limited. We aim to characterize patient, tumor, and treatment factors, and determine variables associated with 5-year overall survival (OS) in individuals with MPNST. Materials and Methods: We utilized the National Cancer Database (NCDB) to identify adult patients diagnosed with MPNST from 2004 to 2015, and analyze patient, tumor, treatment, and survival data. American Joint Committee on Cancer (AJCC 8) staging criteria for STS was utilized. Results: In our cohort of 2,858 patients with MPNST, median age at diagnosis was 47. The 5-year OS rate was 52%. Age, race, tumor size, and treatment regimen significantly predicted 5-year OS on univariate analysis. AJCC 8 stage appeared to predict 5-year OS in head and neck tumors (though not significantly), but not trunk and extremity tumors. Conclusion: While our cohort of patients with MPNST are typically relatively young and healthy, 5-year OS is only 52%. Notably, age extremes, large tumor size, and certain treatment regimens are associated with worse outcomes. While AJCC 8 staging guidelines may have some value in predicting OS in head and neck tumors, they do not reliably risk stratify patients with trunk and extremity MPNST. Ultimately, MPNST is associated with high mortality with few modifiable risk factors, and survival may not be adequately predicted by current staging systems.