Clinical and molecular prognostic predictors of malignant peripheral nerve sheath tumor.

OBJECTIVE: Malignant peripheral nerve sheath tumors (MPNST) are relatively rare sarcomas and poorly understood. We sought to find clinicopathological and molecular predictors of survival for Chinese MPNST patients.
METHODS: Clinical information from 146 MPNST patients treated in the Tianjin Medical University Cancer Institute and Hospital was collected and 56 cases of formalin-fixed and paraffin-embedded tissues were available for immunohistochemical examination of expression of hepatocyte growth factor receptor (c-MET), E3 ubiquitin-protein ligase Mdm2 (MDM2), and TP53.
RESULTS: The 5-year tumor-free survival rate was 24 % and the median tumor-free survival time was 25.64 months. The 5-year overall survival rate was 57 % and the median overall survival time was 132.57 months. The expression patterns of c-MET, TP53, and MDM2 were heterogeneous with total positivity rates of 82.1 % (46/56), 55.4 % (31/56), and 73.2 % (41/56), respectively. The univariate analysis not only showed that tumor size, Neurofibromin 1 (NF1) status, the American Joint Committee on Cancer (AJCC) stage, surgery, MDM2 expression, and TP53 expression had significant correlation with the tumor-free survival, but also demonstrated that radiotherapy, chemotherapy, tumor size, and NF1 status had significant correlation with the overall survival. Even though multivariate analysis found no independent prognostic predictor of MPNST, tumor size and NF1 status had significant correlation with the tumor-free survival and overall survival of MPNST patients.
CONCLUSIONS: With this, the largest documented Chinese cohort, our data supply powerful Chinese evidence of the prognostic role of tumor size and NF1 status in MPNST.