Mass screening for neuroblastoma and mortality in birth cohorts.

Mortality resulting from neuroblastoma in birth cohorts in both Sapporo City and the whole of Japan was investigated to evaluate the effects of a high-performance liquid chromatography (HPLC) mass screening program, targeting on 6 month-old infants. In Sapporo City, the non-HPLC screened cohort showed no reduction in mortality at 4 years of age compared with the pre-screening cohort. However, the HPLC screened cohort showed a reduction of 69% in mortality compared with the pre-screening cohort. On a nation-wide scale, there was a significant decline in mortality for the non-HPLC screened cohort compared with the pre-screening cohort; for the HPLC screened cohort for 1989-1991, there was also a reduction in mortality for children younger than 2 years of age. The incidence of neuroblastoma at 1-4 years of age in the HPLC cohort in Sapporo City was about half that in the pre-screening cohort, along with and probably because of an increasing incidence among infants in the same cohort. Our findings suggest that HPLC screening may detect some poor-prognosis neuroblastoma cases at early stages, thus providing for more favorable therapy.