Diagnosing CNS-PNET tumors: Beyond the microscope

The first step to successfully treating a tumor? Figuring out what it is. And for some tumors, that is difficult.

One such example is a rare, aggressive childhood brain tumor called primitive neuroectodermal tumor of the central nervous system (CNS-PNET). These tumors are hard to diagnose under a microscope, complicating treatment choices.

A new study shows how widespread the problem is and points to a possible solution. Led by St. Jude and the German Cancer Research Center, an international research team used molecular techniques to compare hundreds of tumors classified as CNS-PNET to other known brain tumors.

What they found was surprising: based on the molecular data, 61% of the CNS-PNET tumors could be reclassified as a different type of brain tumor. In many cases, the reclassification suggested a completely different treatment.

Of the remaining tumors, most fell into one of four distinct subgroups. Each had unique molecular patterns and genetic alterations.

“In time, these findings should help us assign patients to the appropriate clinical trial and to improve the design of clinical trials—particularly for precision medicines that target the newly identified genetic alterations,” said Brent Orr, MD, PhD, of St. Jude Pathology.

The results were published in the journal Cell.

Read the news release.