Scientists at the University of Bradford in West Yorkshire, U.K. say they have developed a new blood test that can determine if an individual has cancer. The lymphocyte genome sensitivity (LGS) test could not only detect some cancers earlier than ever before, but it may eventually eliminate the need for some types of biopsies, as well as identify those more likely to develop cancer in the future, according to the research team.
The study (“Sensitivity and specificity of the empirical lymphocyte genome sensitivity assay: implications for improving cancer diagnostics”) was published in the FASEB Journal.
To develop this test, Diana Anderson, Ph.D., and colleagues took blood samples from a group of people that included healthy individuals, cancer patients, and people believed to be at a higher risk than normal to develop cancer. Lymphocytes in these samples were examined in a comet test, by embedding the cells in agar on a microscope slide. In this test, damage to the DNA of the cells was caused by treatment with ultraviolet (UVA) light. This damage was observed in the form of DNA pieces being pulled within the agar in an electric field toward the positive end of the field. This caused a comet-like tail, and the longer the tail, the more DNA damage.
Different thicknesses of the agar were applied to the slides. In healthy people, as different thicknesses were added, DNA-damaged tail responses returned to normal levels. In cancer patients, DNA-damaged tail responses remained high, and in those people who might develop precancerous diseases, tail responses were in between. This means that people with cancer have DNA which is more easily damaged by UVA than do other people, so the test shows the sensitivity to damage of all the genome in a cell, explained Dr. Anderson. The LGS test has been used to examine blood samples from cancer patients with melanoma, colon cancer, and lung cancer, and all gave the same outcomes.
“Optimization allowed test sensitivity or specificity to approach 100% with acceptable complementary measures,” wrote the investigators. “This modified comet assay could represent a stand-alone test or an adjunct to other investigative procedures for detecting cancer.”
