Gene Can Dampen Chemo Drug Effectiveness

WEDNESDAY, June 10 (HealthDay News) -- Women with a certain type of gene may show marked resistance to an important chemotherapy drug used to treat breast cancer, new research suggests.

Scientists at the U.S. National Cancer Institute (NCI) suspect that the variation in the SOD2 gene affects how a patient responds to cyclophosphamide, an agent used against breast tumors, blood cancers and other malignancies. The research is the first to show a mechanism and a biomarker for cyclophosphamide resistance.

Although this is not good news for some patients, the findings have a silver lining: New tests may soon be developed to help doctors screen for genetic markers and create "tailored" therapies, according to an NCI news release.

"In the future, such tests may be used to guide the treatment of patients with the SOD2 variation, ensuring that they receive a therapy that is more effective than cyclophosphamide-based therapy," senior study author Stefan Ambs, of the NCI's Center for Cancer Research, said in the news release.

The study, published online June 9 in Clinical Cancer Research, looked at 588 breast cancer patients in Norway and the United States. Those who had the variation experienced poorer survival on the drug, the researchers found. Scientists believe that the SOD2 variant interferes with the structure and function of an important cellular protein.

More information

The American Cancer Society offers more information on breast cancer.