Agent shows ability to suppress brain metastasis and related damage

• Brain metastasis remains an unconquered challenge in cancer treatment.
• Pigment epithelium-derived factor suppressed brain damage.
• Agent is already being studied for macular degeneration.

"We are making progress from the neck down in cancer treatment, but brain metastases are increasing and are often a primary reason patients with breast cancer do not survive," said Patricia S. Steeg, Ph.D., head of the Women's Cancers Section at the National Cancer Institute's Centre for Cancer Research.

Steeg, who is also a deputy editor of Clinical Cancer Research, another journal of the AACR, said very few drugs that are effective for the treatment of breast cancer break what scientists call the "blood-brain barrier" and treat disease established inside the brain.

Striving to understand

Scientists are striving to understand the mechanisms and effects of brain cancer metastasis.

Steeg and colleagues observed the role of pigment epithelium-derived factor (PEDF) on metastatic breast cancer cell lines. PEDF is currently being studied as a therapy for macular degeneration because it has been shown to protect neurons in the retina.

Researchers found that PEDF managed to suppress the brain metastatic activity of these lines. Furthermore, it exerted a prosurvival effect on neurons and shielded the brain from tumour-induced damage. Specifically, there was a 3.5-fold reduction in the number of dying neurons adjacent to tumours expressing PEDF.

Although further research is needed to confirm these findings and their applicability, Steeg said the findings represent a significant step forward in trying to manage this condition.

This study was supported by the intramural research programs of the National Cancer Institute and the National Eye Institute and by the US Department of Defence Breast Cancer Research Program.