Asthma gene variants may cut risk of brain cancer

New research suggests that gene variants, which are known to raise the risk of Asthma, decrease the risk of glioblastoma multiforme (GBM) , a common type of brain cancer that is rapidly fatal.

Variants or "polymorphisms" are minor changes in a gene that can influence how often the associated protein is produced in a cell and how well it functions.

Several reports have linked Asthma with a reduced risk of brain tumors, but the studies may have suffered from various design issues, said lead author Dr. Judith Schwartzbaum, from Ohio State University in Columbus. "So, to me, the evidence just wasn't credible."

In the present study, Schwartzbaum's team looked for an association between asthma-related gene variants and GBM in a study of 111 patients with this tumor and 422 comparison subjects. An extensive literature search was conducted to identify variants that have been consistently linked to an increased or decreased risk of Asthma.

In agreement with previous findings, self-reported asthma was associated with a decreased risk of GBM, the researchers note in the journal Cancer Research.

Two variants were tied to a heightened risk of GBM, whereas another was associated with a reduced risk. As it turns out, the two former variants are known to decrease the risk of asthma, whereas the latter raises the risk.

"Now I'm interested in determining if these polymorphisms just happen to have independent roles in the two diseases or does having Asthma or allergy symptoms reduce the risk of GBM," Schwartzbaum said.

"I'd also like to find a polymorphism that increases the risk of both diseases," rather than raises the risk of one and lowers the risk of the other. Such a variant could serve as a target for new drugs, she explained.

SOURCE: Cancer Research, July 15, 2005.