Different characteristics of neuroblastomas in cases found by mass screening and non-screening: evaluation of mass screening for neuroblastoma in Kitakyushu City.

Abstract

Neuroblastoma accounts for 24 of 109 patients who have been managed by the pediatric tumor outpatient clinic of our university hospital. Among the malignant solid tumors, neuroblastomas are the most numerous. We investigated neuroblastomas found by mass screening oncologically and epidemiologically. Up until March 31, 1991, seven cases were detected from 64,885 infants who received mass screening by the Kitakyushu City System which we had introduced in 1985. This system is based on an individual health survey program for infants in the city. Six of seven cases found by the screening were treated in our department. None of them, including stage III and stage IV cases, showed any conventional risk factors such as high serum levels of neuron specific enolase, ferritin, amplification of N-myc gene, nor cytogenetic abnormalities. Histopathological studies revealed that ganglioneuroblastoma was observed in 9 of 13 cases over one year of age, whereas it was observed only in two screened cases out of 11 cases under one year of age. According to the classification of Shimada et al., there was one stroma-rich tumor, which is rare in infants and usually a matured type, in the screened cases. Interestingly, another one of the six screened cases regressed spontaneously without any treatment. These cases suggested that some neuroblastomas in the process of maturation or spontaneous regression could be detected by mass screening. On the other hand, 9 of 13 non-screened cases over one-year-old died. Although mass screening at six months of age decreased the mortality rate by neuroblastoma in infancy, the prognosis of neuroblastoma in patients over one-year-old remained still poor. Mass screening should be carried out in a health survey program at one year and six months of age in order to improve the outcome.