University of Minnesota Completes Study of Large-Scale Screening for Childhood Cancer

Infant screening for neuroblastoma, one of the most common forms ofsolid tumors in young children, fails to detect the most severe form ofthe disease, according to a group of international researchers led by Universityof Minnesota faculty. After screening nearly 500,000 Canadian infants forneuroblastoma, the group found that screening did not detect the most severeneuroblastomas even though it found twice as many cancers as had been expected.The researchers conclude that, if left to run their course, some neuroblastomasdetected by screening in infancy either go away or fail to progress. Resultsof the Quebec Neuroblastoma Screening Project appear in the December 21,1996, issue of The Lancet.

"Widespread infant screening for neuroblastoma does not save livesand could subject infants to unnecessary cancer treatments," saidMendel Tuchman, one of three principal investigators of the study. No suchroutine screening programs are currently in place in the United States,added Dr. Tuchman, who is professor of pediatrics and a member of the Universityof Minnesota Cancer Center. Other principal investigators were WilliamWoods, professor of pediatrics and director of the South Carolina CancerCenter at the University of South Carolina; and Bernard Lemieux, professorof pediatrics at the University of Sherbrooke in Quebec. Leslie Robison,holder of the Cancer Center Children's Cancer Research Fund chair in pediatriccancer at the University of Minnesota; and Russell Luepker, professor andhead of the division of epidemiology in the University of Minnesota Schoolof Public Health, also were involved in the study.

"When the disease develops before the child is a year old, it isoften successfully treated," said Tuchman, whose laboratory developedand performed the screening test. "After that age, it could evolverapidly into an advanced stage disease with a very high mortality. It isextremely unfortunate that infant screening does not detect the severeneuroblastomas that develop in older infants."

Two Distinct Types of Neuroblastoma

Researchers now believe that there are at least two distinct types ofneuroblastoma. One that appears at birth or shortly thereafter may resolvespontaneously without leaving any trace of the disease. A more advancedform appears in older infants and carries a high mortality. One in 7,000children is diagnosed with neuroblastoma, making it one of the most commonmalignant tumors in young children. In 90% of cases, the disease affectsthose under 5 years of age.

"While screening for cancer has great appeal, these results demonstratethe importance of large-scale studies to make sure we don't do more harmthan good and end up wasting millons of dollars," said Robison. Priorto the study, many people had advocated for widespread infant screeningin the United States, based on preliminary reports from programs in Japan.

The $6.6 million Quebec Neuroblastoma Screening Project was funded bythe National Cancer Institute (NCI). The NCI grant was based on the resultsof a pilot study in the Twin Cities funded by the American Cancer Society.

Children born between 1989 and 1994 in the Province of Quebec were screenedfor neuroblastoma. Quebec was chosen for the study because it had an establishedprogram to screen for metabolic defects at the age of 3 weeks. Parentssubmitted urine samples from their children at the ages of 3 weeks and6 months. Researchers analyzed samples from 425,816 3-week-olds (91% ofthose eligible). At 6 months of age, samples from 349,706 (75%) of thosechildren were again analyzed. The 118 detected neuroblastoma cases weremore than twice the 54 expected, when compared with newborns in Ontarioand Minnesota, where screening was not performed.