Prognostic factors of patients with primitive neuroectodermal tumor after surgery and multimodal treatment

Objective To evaluate the multimodal treatment outcomes and prognostic factors of patients with primitive neuroectodermal tumor (PNET) after surgery. Methods Clinical data about 41 patients who were diagnosed with PNET in Chinese PLA General Hospital from June 2008 to December 2014 were retrospectively analyzed. There were 24 males and 17 females with the median age of 24 years (ranging from 4 to 65 years). Of the 41 cases, 6 patients were cPNET and 35 patients were pPNET. Original sites included limbs (n=8), brain and head (n=10), spinal canal and paravertebral site (n=4), chest (n=5), abdomen (n=7) and pelvis (n=7). All patients had undergone surgical treatment, including 2 cases with surgery alone, 22 patients with surgery and chemotherapy, 4 patients with surgery and radiotherapy, and 13 patients with surgery, radiotherapy and chemotherapy. Results The overall median survival time was 38 months. The overall survival (OS) rates of 1-year, 3-year and 5-year were 87.8%, 51.9% and 37.1%, respectively. The progression-free survival (PFS) rates of 1- and 2-year were 41.3% and 29%. Twenty-six patients had relapse of this disease (63.4%). Univariate analysis showed that gross tumor resection and recurrence after surgery were negative factors of the prognosis of PNET patients. Local radiotherapy could improve the prognosis of these patients. Multivariate analysis concluded that gross tumor resection and surgery combined with chemoradiotherapy were independent prognostic factors (P=0.006, P=0.013). Conclusion Surgery combined with chemoradiotherapy is still a recommended multimodal treatment regimen for PNET patients. Recurrence after surgery affects the survival of PNET patients severely, and radical resection of tumor can improve the prognosis of PNET patients treated with surgery.