Effects of mass screening for neuroblastoma on incidence, mortality, and survival rates in Osaka, Japan

Objectives: To evaluate the effects of mass screening for neuroblastoma, ti me trends of incidence, mortality, and survival of neuroblastoma in Osaka P refecture were analyzed. Methods: Data for this analysis was obtained from the population-based Osak a Cancer Registry. Time trends of incidence and mortality rates were analyz ed by calendar year and by birth cohort. Survival was compared between befo re and after the introduction off systematic screening. Results: From 1970-94, 457 cases of neuroblastoma and 182 deaths from neuro blastoma were observed in Osaka. The annual age-standardized incidence rate per million children increased from 7.5 in 1970-84 to 20.5 in 1985-94, whi le the mortality rates did not differ between these two periods. Analysis b y birth cohort showed that the incidence rate at 0 year of age per 100,000 live births increased from 2.30 in 1970-79 (unscreened) to 19.80 in 1988-89 (screening by high-performance liquid chromatography, HPLC). The incidence rate in children 1 and 2-4 years of age also increased according to the in troduction of HPLC. The mortality rate in children 1-4 years of age per 100 ,000 live births slightly decreased from 3.87 in 1970-79 to 3.30 in 1988-89 , which was presumed to be derived from the improvement in survival due to the progress in treatment. Conclusions: It is strongly suggested that mass screening for neuroblastoma causes harm because of overdiagnosis, and it has little effect on decreasi ng the incidence and the mortality of neuroblastoma at 1-4 years of age.