German researchers identify enhanced treatment of brain tumors

Glioblastoma is regarded as the most malignant form of brain tumor. In many cases, neurosurgeons are not able to remove such tumors completely because of the risk of destroying too much brain tissue in the process. Moreover, it is often impossible to identify all the fine extensions by which the tumor spreads into surrounding healthy tissue. To at least slow down the growth of tumor cells that have remained in the head, almost all glioblastoma patients are treated by radiotherapy after surgery.

"Unfortunately, we can only delay cancerous growth in this way, but we cannot cure patients. The tumor cells, especially the cancer stem cells, are very resistant to radiation," says Peter Huber, who is head of the Clinical Cooperation Unit 'Radiation Oncology' at the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ).

Studies conducted in recent years found that response to radiation therapy in various cancers is better when certain types of cellular growth factors are blocked at the same time. Glioblastoma cells often produce large amounts of a growth factor called TGF-beta (transforming growth factor beta). High levels of TGF-beta in these tumors are correlated with particularly aggressive growth and a poor prognosis. In addition, the factor seems to support the self-renewal capability of glioblastoma stem cells. "We therefore suspect that blocking TGF-beta signaling pathways slows down the self-renewal of cancer stem cells and, thus, may improve radiation treatment outcomes," Prof Huber adds, explaining the background of the study now published.