A simple blood test could soon allow early detection of breast cancer, according to a new study. Researchers at the Houston Methodist Research Institute have determined that a certain biomarker in the bloodstream can reveal the presence of nascent tumor growth in breast tissue. The findings could transform screening methods and treatment strategies against the cancer that currently kills nearly 40,000 women each year in the U.S. alone.

The study, which is published in the journal Clinical Chemistry, sought to develop new methods of oncological diagnosis by isolating so-called serum biomarkers – observable “signatures” indicative of physiological phenomena. Specifically, the researchers wanted to determine whether the enzyme carboxypeptidase N (CPN) can be said to generate such signatures in the bloodstream. According to senior author Tony Hu, the findings suggest that values associated with CPN not only indicate the presence of breast cancer, but also its stage.

"In this paper we link the catalytic activity of [CPN] to tumor progression in clinical samples from breast cancer patients and a breast cancer animal model," he said in a press release. "Our results indicate that circulating peptides generated by CPN can serve as clear signatures of early disease onset and progression."

The CPN enzyme, which regulates certain proteins after they are created, could thus inspire a new wave of inexpensive, non-invasive breast cancer tests. The researchers estimate that once this biomarker-sensitive technology is finished, a cheap blood sample may be sufficient to identify early tumor growth. "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 current study is the latest in a growing series of inquiries into early oncological diagnosis. In these studies, researchers look for new ways of identifying breast cancer, pancreatic cancer, and other types of tumors that can be difficult to detect before it’s too late. Another example is “Novel Methylation Biomarker Panel for the Early Detection of Pancreatic Cancer” – a National Institutes of Health (NIH) study that ties certain epigenetic alterations in the blood stream to early pancreatic tumor growth.

Source: Y. Li, Y. Li, T. Chen, A. S. Kuklina, P. Bernard, F. J. Esteva, H. Shen, M. Ferrari, Y. Hu. Circulating Proteolytic Products of Carboxypeptidase N for Early Detection of Breast CancerClinical Chemistry, 2013.