Past and future of neuroblastoma screening in Japan.

In Japan, neuroblastoma is a common malignant tumor for children and its prognosis is unfavorable. Since this tumor excretes excessive amounts of vanillylmandelic acid (VMA) and homovanillic acid (HVA), catecholamine metabolites, into urine, both are sensitive diagnostic markers for neuroblastoma. In 1974, to improve the prognosis for neuroblastoma, a mass screening program by a qualitative VMA spot test for early detection of this tumor for 6-month-old infants was started in Kyoto, Japan. Subsequently, mass screening was also conducted in other areas in Japan. In 1985, mass screening commenced as a nationwide program throughout Japan, and in 1988, screening by quantitative measurement of VMA, HVA, and creatinine was recommended by the Ministry of Health and Welfare. During the 6 years from 1984 to 1989, 468 cases of neuroblastoma were detected from among 5,052,165 infants screened by this program. Analysis of findings in the 357 cases detected by mass screening from its inception in Kyoto until December of 1988 have been presented. The survival rate for these cases was 97% (348 of 357 cases). The prognosis of tumors detected by mass screening has clearly been favorable. In addition, survival rates were improved for all cases of neuroblastoma in Kyoto after the introduction of mass screening. The increased incidence of neuroblastoma in infants and the change in age distribution of all cases of neuroblastoma following the inception of urinary screening as well as the occurrence of spontaneous regression of neuroblastoma in relation to the screening program are discussed. Future problems facing mass screening for neuroblastoma are also presented.