PHILADELPHIA, Sept. 24 (UPI) -- New research suggests arteries contain a higher concentration of circulating tumor cells, or CTCs, than veins, calling into question the standard method of taking liquid biopsies for cancer.
Assays to analyze liquid biopsies of blood for CTC are approved for diagnostic use with metastatic breast, colorectal or prostate cancer.
Researchers at Thomas Jefferson University found liquid biopsies may not be as accurate as they could be based on where blood is drawn from.
"If we can validate this approach for uveal melanoma, we hope to be able to catch cancer before it develops into metastatic disease," said Dr. Takami Sato, a professor of medical oncology at Thomas Jefferson University, in a press release. "On the other hand, our research raised a concern that venous blood specimencs, which are tested as the standard practice for CTC measurement, might not be the best source for CTC detection."
Researchers working with 17 uveal melanoma patients took blood from both the femoral arteries and antecubital veins to test for CTCs.
They reported CTCs were detected in 100 percent of the arterial blood samples, and 52.9 percent of those taken from veins.
"Our data indicate that arterial blood specimens might be a better source of circulating uveal melanoma cells," researchers wrote in the study. "Although less conveniently processed, perhaps arterial blood should be evaluated as sample source for measurement of CTCs."
The study is published at EBioMedicine.