Survival and prognosis of neurofibromatosis type 1-associated malignant peripheral nerve sheath tumours: a systematic review and meta-analysis

BACKGROUND: Malignant peripheral nerve sheath tumour (MPNST) is a rare, aggressive sarcoma with high mortality. MPNST can develop sporadically, after radiation therapy or in association with neurofibromatosis type 1 (NF1). The treatment is challenging especially if surgical removal is not possible. NF1 is an autosomal-dominant genetic disorder most often caused by a germline pathogenic variant in the NF1 gene and in rare cases a deletion of the NF1 gene. Patients with NF1 have a higher risk of developing several different cancers, of which MPNST is one of the most frequent. MPNST in individuals with NF1 often presents with large MPNST which are often not accessible for surgery. Several studies have shown that patients with NF1-associated MPNST (nfMPNST) have an overall inferior survival than those with sporadic MPNST (sMPNST). Despite this, NF1 status alone may not be a causative factor for poor prognosis, which might rather be due to the incidence of larger tumours, which are more challenging to resect in toto. METHODS AND RESULTS: A systematic research protocol was made using the PRISMA-P model and the review question and inclusion and exclusion criteria were defined using the PICO model. The study characteristics defined by PICO include patients with NF1 as the population of interest. The development of MPNST was considered as the intervention, patients with sMPNST were chosen for comparison and the primary outcome of interest was survival. The literature search was performed on 12 October 2024 and 4,394 studies were eligible for screening, of which 36 studies were included in this study. Meta-analysis of eight studies found NF1 status to be a risk factor for the survival of MPNST. The reported survival rates varied between studies, but the 5-year overall survival (OS) remained poor in general, Awith 15 studies showing a significantly inferior survival for nfMPNST. Only four studies have a worse survival for sMPNST, but none with a significant difference. CONCLUSION: The findings in this systematic review and meta-analysis of 36 studies indicates that patients with nfMPNST have a worse survival compared to sMPNST.