Amplification of 9q34 in childhood adrenocortical tumors: a specific feature unrelated to ethnic origin or living conditions

Adrenocortical tumors (ACT) in children under 15 years of age exhibit some clinical and biological features distinct from ACT in adults. Cell prolifer ation, hypertrophy and cell death in adrenal cortex during the last months of gestation and the immediate postnatal period seem to be critical for the origin of ACT in children. Studies with large numbers of patients with chi ldhood ACT have indicated a median age at diagnosis of about 4 years. In ou r institution, the median age was 3 years and 5 months, while the median ag e for first signs and symptoms was 2 years and 5 months (N = 72). Using the comparative genomic hybridization technique, we have reported a high frequ ency of 9q34 amplification in adenomas and carcinomas. This finding has bee n confirmed more recently by investigators in England. The lower socioecono mic status, the distinctive ethnic groups and all the regional differences in Southern Brazil in relation to patients in England indicate that these d ifferences are not important to determine 9q34 amplification. Candidate amp lified genes mapped to this locus are currently being investigated and Sout hern blot results obtained so far have discarded amplification of the abl o ncogene. Amplification of 9q34 has not been found to be related to tumor si ze, staging, or malignant histopathological features, nor does it seem to b e responsible for the higher incidence of ACT observed in Southern Brazil, but could be related to an ACT from embryonic origin.