Incidence of neuroblastoma after a screening program.

Purpose: A significant increase in the incidence of neuroblastoma occurred among a 5-year birth cohort (May 1989 to April 1994) during an active urinary screening program for its early detection. We examined the postscreening incidence of neuroblastoma in the subsequent 5-year birth cohort (May 1994 to April 1999), with follow-up to 2002, to determine whether the incidence remained increased.
Patients and Methods: We reviewed institutional records of patients diagnosed with neuroblastoma during the period from 1994 to 2002 who were born in 1994 to 1999 in the province of Quebec, as well as in the state of Minnesota and the province of Ontario, regions that had served as controls during the screening interval. We calculated and compared incidence rates during the 1994 to 2002 time period.
Results: For the 5-year birth cohort as a whole, the rate of newly diagnosed neuroblastoma was higher in Quebec than in the control populations of Minnesota and Ontario (standardized incidence ratio, 1.34; 95% CI, 1.03 to 1.70). However, in years 4 and 5 of the interval, population-based incidence declined to the same levels as those seen in the control areas.
Conclusion: The institution of a urinary screening program for neuroblastoma led to increased awareness of the diagnosis and an elevated rate of diagnosis even after the completion of the screening evaluation. However, this halo effect was transient, with diagnostic rates subsequently decreasing within the range seen in control populations.