Stephen L. Gans overseas lecture. Mass screening for neuroblastoma in Japan: lessons learned and future directions.

BACKGROUND/PURPOSE Since 1985, a nationwide mass screening program (MS) for neuroblastoma has been conducted for 6-month-old infants throughout Japan, resulting in the detection of more than 1,900 cases of neuroblastoma. The outcome of these patients has been excellent: more than 97% of them are alive. Yet, several reports suggest that the number of advanced-stage neuroblastoma patients over 1 year of age has not changed substantially. The current report focuses on the 15-year experience with MS of the Kyushu Pediatric Oncology Study Group. METHODS The clinical and biological features of neuroblastoms detected (n = 320) and not detected by MS (n = 245) were compared. Regional and national statistics for neuroblastoma before and after 1985 were analyzed using standard epidemiologic measures for the occurrence of disease. RESULTS The majority of the MS-positive cases were biologically favorable and had an excellent outcome. In contrast, the majority of non-MS patients in whom neuroblastoma later developed had advanced-stage, unfavorable-prognosis tumors. The overall mortality rate of neuroblastoma in the Kyushu area was not improved by MS. CONCLUSIONS The optimal time for screening is the point at which neuroblastomas regressing spontaneously can no longer be detected, but more aggressive disease can be found. A birth cohort study could determine the optimal timing for a second screening. Identification of other new prognostic factors may be required.