[Long-term follow-up of neuroblastoma in children less than 18 months of age].

Objective: To assess the clinical features and long-term outcomes of neuroblastoma (NB) in children less than 18 months of age, so as to provide evidence for further improvement of treatment. Method: Clinical data(sex, age, stage, risk group, treatment response, follow-up, etc.) of 155 NB patients under age of 18 months from June 2000 to December 2015 in Shanghai Children's Medical Center were analyzed retrospectively. The clinical features were summarized and the long-term follow-up results were evaluated. The overall survival (OS) and event-free survival (EFS) were analyzed by using Kaplan-Meier method. Factors including age, stage, risk group, bone marrow and bone metastasis, N-MYC status and dehydrogenase(LDH) level were analyzed by Log-Rank test. Result: Totally 155 eligible patients (96 males, 59 females) were included. The median age of disease onset was 7 months (11 days to 18 months). There were 31 cases of stage 1, 19 cases of stage 2, 45 cases of stage 3, 38 cases of stage 4 and 21 cases of stage 4S. The median follow-up time was 36 months (range 4 to 189 months), the 3-year and 5-year EFS rate were 89.6% and 85.2% respectively and the 3-year and 5-year OS rate were 96.2% and 94.1%, respectively. A total of 15 recurrent or progressed cases were observed. The median time to first recurrence was 11 months (range 3 to 39 months), 6 cases eventually died. Second malignancy occurred in one patient. The patients who had relapsed disease within 12 months from initial diagnosis have much lower 3-year OS rate than those in whom the disease recurred 12 months later (25.7% vs . 83.3%, P =0.020). Although the number of chemotherapy courses in median-high risk group reduced from 8.6 courses to 7.5 courses after the revision in 2008, the survival rate showed no significant difference between before and after (5-year EFS 74.4% vs . 84.3%, 5-year OS 89.0% vs . 92.9%, both P >0.05). In patients with stage 1 and stage 2, the 3-year EFS of 34 cases with surgery alone and 16 cases accepted chemotherapy were both 100%. Age at diagnosis, stage, risk group, MYCN status, LDH level, bone marrow involvement and bone infiltration had significant impacts on prognosis(all P <0.05). Conclusion: Satisfactory outcomes could be achieved in neuroblastoma in children aged within 18 months; the prognosis was better in children at age less than 12 months compared with 12-18 months. MYCN amplification, LDH more than 5 times upper limit of normal range, bone marrow and bone infiltration were associated with worse prognosis.Excellent survival rates could be achieved in children with stage 1 and 2 disease within 18 month's old accepted surgery alone, chemotherapy or radiotherapy could be avoided in these patients so as to reduce long-term adverse reactions.