Researchers may have unlocked a door to the discovery of how breast cancer metastasizes to the brain, leading to optimism about future treatments of the disease.

Dr. Diane Palmieri of the National Cancer Institute, Rockville, Md., says the gene, hexokinase 2, was more highly expressed in brain metastasis in patients with breast cancer than in primary breast tumors. The study containing this discovery was published in Molecular Cancer Research. Hexokinase 2 plays a starring role in glucose metabolism, which provides fodder for tumors to grow. It also effects apoptosis, the cell survival process.

"Potential therapies would need to turn off this gene and thus starve the tumor of its growth potential," Dr. Palmieri says.

Researchers analyzed both primary tumors as well as brain metastases, finding higher levels of hexokinase 2 in the metastatic tumors compared to unrelated primary tumors. The median survival for patients with high levels of hexokinase 2 expression in their brain metastasis was 9.6 months, but patients survived a median of 17.5 months for those with lower expression. This finding is a giant step in the search for a breast cancer cure, Dr. Brunhilde Felding-Habermann says.

"Improvements in breast cancer therapy have made prognoses like brain metastasis a growing problem," says Dr. Felding-Habermann, an associate professor at the Scripps Research Institute, La Jolla, Calif., "and this research points to a potential target for future therapies."