Abstract:OBJECTIVE: This study aimed to investigate the effect of clearance of tumor cells in autologous bone marrow after induction chemotherapy (based on RT-PCR detection) on the outcome in patients with neuroblastoma. METHODS: Thirty-two neuroblastoma patients with histological bone marrow metastasis at diagnosis but without tumor cells in marrow based on the immunohistochemistry detection after induction therapy were eligible to this study. The neuroendocrine protein gene product 9.5 (PGP9.5) was measured with RT-PCR, as a bio-marker to detect the presence of tumor cells in bone marrow at diagnosis and after induction chemotherapy. RESULTS: All patients were PGP9.5 positive in bone marrow at diagnosis. After induction chemotherapy, 16 patients remained PGP9.5 positive in marrows. A 3.4±0.9 year-follow-up showed a relapse in 11 out of the 16 patients, with event free survival (EFS) of 31%. In contrast, among the other 16 PGP9.5 negative patients, only 5 relapsed after (3.2±0.7 years) treatment, with EFS of 69%(P = 0.018). Conclusions Clearance of neuroblastoma cells through induction chemotherapy (based on RT-PCR detection) in autologous bone marrow is associated with better prognosis in patients with neuroblastoma.
