High-Dose Chemotherapy and Autologous Stem Cell Transplantation In Patients With High-Risk Neuroblastoma : Results Of Turkish Pediatric Oncology Group- Neuroblastoma 2003 (TPOG-NBL 2003) Protocol

TPOG-NBL 2003 national protocol was designed to improve treatment results of the high risk patients by adjunction of stem cell rescue with intensive multimodal therapy.

High risk stratification was made according to COG criteria. Just before the third cycle of chemotherapy, patients without progression were allocated into two treatment groups non-randomly by physicians’ and/or parent’s choices guided to the center’s facility, toxicity and social-economical facility to attain the megatherapy. After an induction of 6 chemotherapy cycles, the protocol was divided into two arms which were designed to continue the intensive conventional chemotherapy (CCT), or initiate myeloablative therapy with autologous stem-cell rescue (ASCR). All patients were also given 13-cis-retinoic acid as maintenance therapy.

Fifty-six percent (272 patients) of all neuroblastoma patients was evaluated as high risk. Response rate to induction chemotherapy was 81% (CR/VGPR: 32%, PR: 49%) in patients at the end of induction chemotherapy. Overall EFS and OS at 3-years were 36% and 45%, respectively. Intention-to-treat analysis documented post-induction (after the six cycles of induction chemotherapy) EFS of 46% in CCT arm (137 patients) and 37% in ASCR group (55 patients) (p= 0.037); whereas, OS was 59% and 43%, respectively (p=0.052). Thirty-one patients (11%) died of treatment-related complications.

Survival rates of high-risk neuroblastoma have improved over the last decade in Turkey. The main problems when managing these patients were an effective local control, early progression and death. Megatherapy has not augmented the therapeutic end point in our country’s circumstances. However; the better the supportive care and the higher the patients’ compliance is attained, the higher the survival rates might be obtained in Turkish neuroblastoma patients.

No relevant conflicts of interest to declare.