Screening for neuroblastoma: a 9-year birth cohort-based study in Niigata, Japan.

Between April 1985 and March 1994 (9 years), 229,346 babies were born in Niigata prefecture, and 201,888 (88.0%) underwent mass screening (MS) for neuroblastoma at 6 months of age. To date, 29 infants have been screen-detected as having neuroblastoma (1:7908). All screen-detected patients survived after removal of the primary tumor. In the same birth cohort, 17 additional children were clinically diagnosed as having neuroblastoma. The cumulative incidence rate of neuroblastoma at 5 years of age was 10.5 per 100,000 live births in the 5-year birth cohort before MS was introduced, and 18.6 per 100,000 in the first 5-year birth cohort after MS was introduced. These values were not statistically different. The birth cohort incidence rate increased significantly to 22.2 per 100,000 (p < 5% compared with before MS) after the method of MS was changed to high-power liquid chromatography (HPLC), even though this latest birth cohort has not been followed for 5 years. The population-based mortality rate from neuroblastoma was 5.9 per 100,000 in the 5-year birth cohort before MS, and 4.5 per 100,000 after MS in the first 5-year birth cohort, using the vanillymandelic acid (VMA) spot test. These values were not statistically significant. In contrast, no death was observed in the next 4-year birth cohort after MS using HPLC; however, this birth cohort has not yet been followed for 5 years.