Survival and NF1 Analysis in a Cohort of Orthopedics Patients with Malignant Peripheral Nerve Sheath Tumors

Daniel K Knewitz; Colin J Anderson; William T Presley; MaryBeth Horodyski; Mark T Scarborough; Margaret R Wallace

doi:10.1155/2021/9386823

Survival and NF1 Analysis in a Cohort of Orthopedics Patients with Malignant Peripheral Nerve Sheath Tumors

Sarcoma. 2021 Oct 4:2021:9386823. doi: 10.1155/2021/9386823. eCollection 2021.

Authors

Daniel K Knewitz¹, Colin J Anderson^{2

3}, William T Presley⁴, MaryBeth Horodyski², Mark T Scarborough^{2

5}, Margaret R Wallace^{4

5

6}

Affiliations

¹ University of Florida College of Medicine, MS3, Gainesville, FL, USA.
² Department of Orthopaedics and Rehabilitation, University of Florida College of Medicine, Gainesville, FL, USA.
³ Department of Orthopedic Surgery, Levine Cancer Institute and Musculoskeletal Institute, Carolinas Medical Center-Atrium Health, Charlotte, NC, USA.
⁴ Department of Molecular Genetics & Microbiology, University of Florida College of Medicine, Gainesville, FL, USA.
⁵ University of Florida Health Cancer Center, Gainesville, FL, USA.
⁶ University of Florida Genetics Institute, Gainesville, FL, USA.

Abstract

Neurofibromatosis type 1 (NF1) is an autosomal dominant tumor syndrome in which benign plexiform neurofibromas are at risk of transforming into malignant peripheral nerve sheath tumors (MPNSTs), a very rare soft-tissue sarcoma. The prognosis of patients with MPNSTs is poor, with most studies reporting <50% survival at five years. However, studies evaluating MPNSTs are limited and report heterogeneous results. Because no MPNST-specific evidence-based treatment guideline exists, individual institutional experiences are very informative to the field. The main objective of this study was to investigate and report MPNST prognostic clinical and genetic biomarkers from our institution's Orthopedics service experience treating 20 cases from 1992 to 2017. Most patients were treated with resection and adjuvant radiation. Extended follow-up, averaging 11.4 years (ranging 1.1 to 25.1), revealed excellent five-year survival rates: 70% for overall and 60% for metastatic disease. An S100 B immunonegative tumor phenotype was associated with a significantly worse outcome than MPNSTs with positive S100 B stain. In addition, NF1 gene mutation analysis was performed on 27 families with NF1 in which at least one affected family member developed MPNSTs. Of the 27 NF1 germline mutations, five were large deletions spanning (or nearly spanning) the gene (18.5%), substantially more than such deletions in NF1 in general, consistent with increased risk of MPNSTs in such cases.