NEUROBLASTOMA SCREENING IN INFANTS POSTPONED AFTER THE 6TH-MONTH OF AGE - A TRIAL TO REDUCE OVERDIAGNOSIS AND TO DETECT CASES WITH UNFAVORABLE BIOLOGIC FEATURES

Background. Encouraged by Japanese reports of the benefits of screenin g 6-month-old infants for neuroblastoma, a neuroblastoma screening pro gram was introduced in Austria in 1991. However, because of concerns r elated to ''overdiagnosis'' by screening at this age, the screening te st was performed at a later age. Methods. From March 1991 to February 1995 neuroblastoma screening was performed on filter paper urine speci mens in 100,043 Austrian infants (median age 8.5 months). Primary anal ysis of urine catecholamines (vanillylmandelic acid and homovanillic a cid) was per formed by use of an EIA method. Questionable or positive results were confirmed by high performance liquid chromatography (HPLC ). A double retest was requested following a positive HPLC result. Res ults. Twenty-one infants were admitted to a hospital following repeate dly elevated values of vanillylmandelic acid (VMA) and/or homovanillic acid (HVA). Eleven infants were found to have neuroblastoma (three st age 1, four stage 2 B, lour stage 3). Treatment consisted of surgery a lone with total or subtotal resection in eight cases, surgery and chem otherapy in two cases, and chemotherapy alone in one case. Biologic fe atures were assessed in all tumors excluding ploidy in one case. The m ajority of the tumors analyzed were near-triploid (9/10), however, two tumors revealed N-myc amplification. Conclusion. Our results demonstr ate that stage distribution and biologic features oi neuroblastomas di agnosed by screening at 8.5 months are different from the results of s creening at 6 months. Furthermore, the detection of one neuroblastoma among 9,100 screened infants is significantly lower than the incidence of the Japanese screening program. Our results suggest that screening at an age of 7 to 10 months reduces overdiagnosis and may be of more benefit than earlier screening. (C) 1997 Wiley-Liss, Inc.