BACKGROUND: An indolent course is associated with neuroblastoma (NB) in adolescents and adults. In the current study, the authors analyzed this phenomenon in a large series of children with metastatic NB. METHODS: The authors studied 38 patients who were diagnosed with NB in the first decade of life and had metastatic disease 5 years or more from diagnosis. RESULTS: The median age at diagnosis was 3 years 10 months. MYCN was amplified in 2 of 28 patients tested. Of 30 patients with classic Stage 4 NB, 9 had a late first recurrence of disease (4.3-13 years from diagnosis). Of eight patients who had atypical cases at diagnosis (one isolated mandibular lesion, two Stage 4-N, five non-Stage 4), six had a late first distant recurrence of disease (4 years 11 months-38 years 8 months). Nineteen patients were off therapy continuously for 3 years or more before disease recurred a first or second time. Myeloablative therapy was used to consolidate a first or second response in 27 patients. High-dose conventional therapy helped to achieve a second remission of disease in 9 of 20 patients assessable for response of first recurrence but achieved no major responses of second or third relapse in 10 of 11 patients. The combination of anti-G(D2) immunotherapy and/or cis-retinoic acid, targeted radiotherapy, and multiple cycles of chemotherapy with modest toxicity helped prolong survival. Twelve patients survive at 5 years 6 months+ to 19 years 4 months+ from diagnosis (median, 6 years 10 months+), including four with complete remission of disease; 10 received anti-G(D2) immunotherapy after recurrence. The other 26 patients died of disease (n = 22) or toxicity (n = 4) at 5 years-41 years 5 months from diagnosis (median, 6 years 5 months). CONCLUSIONS: The concept of indolent or smoldering NB should not be limited to adolescents/adults. The expanding repertoire of anti-NB treatments, including biologic therapies and chemotherapy regimens of modest toxicity, can convert childhood NB into a chronic disease with prolonged survival after recurrence.
