Findings indicate breast cancer blood test may be possible

Preliminary studies identified the presence of breast cancer cells from serum biomarkers indicating a blood test may be possible, U.S. researchers say. Study leader biomedical engineer Tony Hu of Houston Methodist Research Institute in Houston and colleagues at the New York University Cancer Institute said the mixture of free-floating blood proteins created by the enzyme carboxypeptidase N accurately predicted the presence of early-stage breast cancer tissue in mice and in a small population of human patients. CPN is an enzyme that modifies proteins after the proteins are first created. Past studies have only shown the enzyme is more active in lung cancer patients. The study is the first to show CPN isn't merely more active in breast cancer patients, but there's more of it, Hu said. "In this paper we link the catalytic activity of carboxypeptidase N to tumor progression in clinical samples from breast cancer patients and a breast cancer animal model," Hu said in a statement. "Our results indicate that circulating peptides generated by CPN can serve as clear signatures of early disease onset and progression." The technology is not yet available to the public, and might not be for years, Hu said more extensive clinical tests are needed, and those tests are expected to begin in early 2014. "What we are trying to create is a non-invasive test that profiles what's going on at a tissue site without having to do a biopsy or costly imaging," Hu said. "We think this could be better for patients and -- if we are successful -- a lot cheaper than the technology that exists. While there's more to the cost of administering a test than materials alone, right now those materials only cost about $10 per test." The findings were published in Clinical Chemistry.