Molecular groups give context to clinical results

Clinical trials can run for many years. From start to finish, they can sometimes take a decade or longer. But science doesn’t stop during that time. New knowledge can change the context of a long-standing clinical trial.

This is the case with a Children’s Oncology Group (COG) study for children with high-risk medulloblastoma, the most common malignant childhood brain tumor. The study added the chemotherapy drug carboplatin to treatment.

St. Jude research found medulloblastoma has four molecular groups. These groups are WNT, SHH, Group 3 and Group 4. The discovery occurred after the COG study began.

Now that the clinical trial data is in, St. Jude scientists looked at tumor samples from the trial. They assigned participants to molecular groups. The findings changed how the trial’s results were interpreted.

“If all the patients were lumped together, there was only a slight trend toward higher survival,” said Paul Northcott, PhD, Developmental Neurobiology. “But when you look specifically at Group 3, there is a 20% jump in survival. That is a dramatic improvement for such a high-risk group.”

JAMA Oncology published a report on this work.