Childhood cancer clue.

In 1983, Paul Zeltzer of the University of Texas Health Science Center at San Antonio and his colleagues found that children with neuroblastoma, a nerve cell cancer, had high levels of an enzyme called NSE (neuron-specific enolase) in the tumor and bloodstream. They have now found that children with medulloblastoma, a brain tumor, also have high levels of the enzyme.

Brain tumors are the second most common childhood cancer, behind leukemia, and neuroblastoma is third. Both neuroblastoma and medulloblastoma are often fatal.

finding high levels of the same enzyme in the two tumors suggests a biochemical link that could help with treatment. "If we find a group of drugs that are successful in treating one, they may be useful for the other," ZELTZER TOLD SCIENCE NEWS.

With neuroblastoma, levels of the enzyme are measured to establish the severity of the cancer and how aggressively it should be treated. "This enzyme is like a sophisticated crystal ball," Zeltzer says. If the enzyme level is as predictive in medulloblastoma, children with a low NSE level can be spared toxic, experimental treatments.

Other advantages, notes Zeltzer, are that it could make diagnosis easier and provide a market of effectiveness of treatment.