[The treatment and prognosis of peripheral primitive neuroectodermal tumor]

Objective: To evaluate the treatment and prognosis of peripheral primitive neuroectodermal tumor (pPNET). Methods: From March 2006 to April 2015, 47 patients with pPNET who had undergone chemotherapy in our hospital were enrolled. The clinical data and survival information of these patients were collected and interpreted retrospectively to analyze the effect of each treatment on the survival of patients. Results: The median overall survival (OS) for whole group was 23.5 months, and 5-year survival rate was 33.8%. In the patients who underwent radical surgery, the median OS was 70.4 months, the 5-year survival rate was 54.4%, the median disease-free survival (DFS) was 23.1months, and 5-year DFS rate was 34.4%. Sixteen patients had recurrences or metastasis after surgery. Eighty-one percent of them (13/16) occurred within 2 years after surgery. The difference of median OS between patients who got adjuvant chemotherapy and those who did not was statistically significant (P=0.04). But the difference of median PFS between these two groups was not statistically significant (P=0.057). There was no statistically significant difference for median OS (P=0.619) and median DFS (P=0.191) between patients who got adjuvant radiotherapy and those who did not. The recurrence rate between these two groups was not statistically significant (P=0.40). The median OS and PFS for 34 patients who received first-line palliative chemotherapy was 10.7 months and 3.2 months. 1-year and 2-year survival rates were 48.0% and 17.8%. The response rate and clinical benefit rate for first-line chemotherapy was 53.1% and 75.0%. The median PFS and OS for patients who received platinum-based regimens were 3.3 months and 14.5 months. The median PFS and OS for patients who got non-platinum regimens were 2.7 months and 10.3 months. There was no significant difference of PFS and OS between platinum-based and non-platinum regimens. Palliative surgery and radiotherapy did not improve the OS of pPNET this cohort. Conclusions: Comprehensive treatment including chemotherapy, radiotherapy and surgery is the standard treatment model for early pPNET patients. Adjuvant chemotherapy significantly improved the overall survival of early pPNET patients. Chemotherapy is the main treatment for patients with advanced pPNET. Platinum-based chemotherapy seem to be a good option.