[Neuroblastoma in children under than 1 year of age]

Our objective was to carry out a prospective multicenter study of neuroblastoma patients diagnosed between 0 and 12 months of age.

Diagnostic procedures included histology, catecholamine excretion, bone marrow cytology and MIBG-scan. Staging was evaluated according to the INSS classification. After 1992, Simada criteria were used and also N-myc amplification, DNA index and P-glycoprotein determinations in tumoral tissue. The surgical technique employed and complications derived from it were also evaluated. The patients were treated according to stage with multicenter Spanish protocols N-I-87 and N-II-92. Overall survival and event free survival were calculated by actuarial methods.

Between October 1987 and June 1992, a total of 140 infants less than one year of age were registered and diagnosed of neuroblastoma, representing 40% of all neuroblastoma cases. Median age was 0.3 years and 73% were less than 6 months of age at diagnosis. The most frequent stage was 1 (35%) followed by 4-S (20%). The frequency of unfavorable prognostic factors was the following: LDH (21%), NSE (14%), ferritin (18%), Shimada (7%), DNA (35%), NMA (3%), TrakA (23%), P-glycoprotein (19%). Surgery was performed in 133 children: total resection was reported in 94 and > 90% in another 22 cases. Complications attributed to surgery occurred in 12% of the cases. Chemotherapy was given in 73 cases and radiotherapy in 7. The five year total survival is 91% and the event free survival 88%. Survival by stages: Stage 1 = 91%, stage 2A = 88%, stage 2B = 100%, stage 3 = 84%, stage 4 = 56% and stage 4-S = 100%.

1) The majority of neuroblastoma cases in infants less than one year old are diagnosed before six months of age. 2) For this age group stages 1 and 4-S are the most frequently observed. 3) Unfavorable biological factors are less frequent than for children over one year of age and are associated with disseminated disease (advanced stage). 4) The outcome is excellent, except for stage 4 patients. The cases in stage 1 and 2 may be treated by surgery alone. Chemotherapy may be of benefit for stage 3 patients.