Neuroblastoma screening in Japan: population-based cohort study and future aspects of screening.

INTRODUCTION

It is unknown whether screening for neuroblastoma has the benefit of reducing the incidence of advanced diseaseor mortality due to neuroblastoma.Japanese nationwide massscreening for 6 month old infants was launched in 1985 and was performed using quantitative high-performance liquid chromatography (HPLC) between years 1990 to 2003.

MATERIALS AND METHODS

We compared the incidence rates (IR) and the mortality rates (MR) per 100,000 births of neuroblastomas diagnosed before 6 years of age between 2 cohorts: children born during the years 1980 to1984 (Pre-screen cohort, n = 7,620,203) and 1990 to1998 (Screen cohort, n = 10,878,918). We then proposed the optimal timing and procedures for future screening.

RESULTS

Cumulative IR in the Screen cohortwas significantly higher than the Pre-screen cohort (29.80 vs. 11.96, P <0.0001). On the other hand, IR of neuroblastoma diagnosed after 24 months old in the Screen cohort was significantly lower than in the Pre-screen cohort (P <0.0001). The cumulative MR of the Pre-screen cohort was 5.35, whereas that of the Screen cohort was 2.82 (P <0.0001).

CONCLUSIONS

HPLC mass-screening for neuroblastoma at 6 months of age found a marked increase in incidence in younger children (less than 12 month old) and a significant decrease in mortality rates overall. To reduce overdiagnosis of regressing cases and to identify preclinical stages of unfavourable cases, we propose using HPLC-screening at 18 months of age.