Researchers have successfully identified the presence of breast cancer cells from serum biomarkers. The carboxypeptidase N enzyme accurately predicted the presence of breast cancer tissue in mice and a small group of human patients. The test is not available to the public as additional studies are required.
"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," said biomedical engineer Tony Hu, who led the project. "Our results indicate that circulating peptides generated by CPN can serve as clear signatures of early disease onset and progression."
There are, at present, no inexpensive tests to detect breast cancer, and the new test would be a non-invasive detection technique, not requiring costly biopsies and imaging.
CPN is an enzyme that alters proteins after they are formed. It was previously linked to lung cancer but has been linked to the detection of breast cancer as well.
What makes Hu's research interesting is that they are separating and detecting low levels of peptides created by CPN normally believed to originate near cancerous cells. By studying these peptides, they could get an estimate of what stage the cancer is in.
But they found that the CPN levels dropped with time, suggesting that it may be difficult to detect later stages of the cancer.
"Even at the eighth week, CPN activity was still significantly higher than baseline," Hu said. "However, we suspect the activity of different enzymes goes up and down as the disease progresses. We will be looking at how we might add known and future biomarkers to the blood test to increase its robustness and accuracy."