Response to N7 induction chemotherapy in children more than one year of age diagnosed with metastatic neuroblastoma treated in UKCCSG centers

Abstract

Background: The highest reported metastatic response rate to induction chemotherapy in patients with neuroblastoma has been achieved by Kushner et al. [Kushner et al.: J Clin Oncol 12:2607-2613,1994; Cheung et al.: Med Pediatr Oncol 36: 227-230, 2001; Kushner et al.: J Clin Oncol 22:4888-4892, 2004] using their N6 and subsequently N7 protocols. This N7 induction was adopted by UKCCSG for new patients in 1999.

Methods: Forty-seven children with metastatic neuroblastoma were recruited between 1999 and 2002. They received the N7 intensive chemotherapy protocol, after full staging including evaluation by I123mIBG imaging where possible.

Results: Thirty patients with positive mIBG scans were evaluable for response, and complete resolution of metastatic disease was obtained in 16 (53.3%). Fourteen patients without positive mIBG scans were evaluated for response according to bone marrow and bone scan data and 11 (78.6%) cleared metastatic disease. The toxicity of this induction therapy was similar to that seen in previous UK protocols, although 14 patients had Brock grade 3 or 4 ototoxicity. Thirty-three patients proceeded to high-dose therapy with no unanticipated toxicities. For the whole group of 44 evaluable patients, the 3-year event-free survival (EFS) and overall survival (OS) were 38.3 and 46.7%, respectively.

Conclusions: Although feasible in terms of delivery, when used in the UKCCSG centers, this protocol achieved a much lower response rate than in the previously published series in the US [Kushner et al.: J Clin Oncol 12:2607-2613,1994; Cheung et al.: Med Pediatr Oncol 36: 227-230, 2001; Kushner et al.: J Clin Oncol 22:4888-4892, 2004].