A newly identified gene, called metadherin, might cause breast cancer tumors to spread and become resistant to chemotherapy, according to a study published Tuesday in the journal Cancer Cell, the Baltimore Sun reports. According to the Sun, patients with localized breast cancer have a five-year survival rate of 98%, but women with metastasized breast cancer have a five-year survival rate of 27%. The Sun reports that the newly discovered gene appears to make tumor cells "sticky," allowing them to adhere to blood vessels in various organs and penetrate surrounding tissue. The study found that many copies of metadherin were present in a large percentage of aggressive and deadly cancers. Unlike recent developments related to the BRCA1 and BRCA2 gene mutations, which increase the likelihood of developing breast cancer, the new gene is not expected to aid doctors in preventing cancer from developing. Rather, "[i]t would predict whether the patient's breast cancer is likely to spread and kill," the Sun reports (Desmon, Baltimore Sun, 1/6).

Yibin Kang, assistant professor of molecular biology at Princeton University, and colleagues from the Cancer Institute of New Jersey found that metadherin is "overrepresented" in 30% to 40% of the breast cancer patients studied. Kang said that the tumor cells with an over-expression of the metadherin gene were "tougher" and "survive[d] better when attacked by a broad spectrum of drugs." However, when the researchers genetically altered the tumors to remove the metadherin, chemotherapy attacked the tumor more effectively, he said (Chambers, Newark Star-Ledger, 1/6).

Kang said that the team is hopeful about the development of a drug to block the expression of metadherin, adding that pharmaceutical companies are examining the study's findings (Newark Star-Ledger, 1/6). Ben Park, an associate professor of oncology at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University, called the study "hypothesis-generating ... not hypothesis-proving" (Baltimore Sun, 1/6). He added that he is skeptical that a single gene will provide the "magic bullet" for targeting the disease (Newark Star-Ledger, 1/6).

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