HudsonAlpha Institute for Biotechnology researchers have discovered a measurable indicator in blood plasma that could identify patients who have colon polyps.
The finding is an important first step in developing a blood test to screen for colon polyps that could become cancerous or even for colon cancer. The study was published online last week in Clinical Cancer Research, a publication of the American Association for Cancer Research.
“A blood test that fulfills the role currently played by colonoscopies would have major positive impacts,” said Brian Roberts, a senior scientist in the Myers Lab at HudsonAlpha and the lead author for the published study.
“A lot of people joke about how they’d love to avoid the discomfort of colonoscopies,” he said, “but there’s a serious issue with people not actually getting screened.”
According to the American Cancer Society, of the adults age 50 and older for whom physicians recommend a colonoscopy screening, only about 65 percent comply.
For the project, Roberts and a group of scientists from four labs across HudsonAlpha studied small RNA – short strands of ribonucleic acid – in blood plasma collected from patients at the University of Alabama at Birmingham (UAB) School of Medicine. The sample collection was part of a collaboration with Dr. Robert Kimberly and Meredith Fitz-Gerald at the Center for Clinical and Translational Science at UAB; and Dr. C. Mel Wilcox, director of the Gastroenterology and Hepatology Division in the Department of Medicine at UAB.
RNA is present in all cells, and while its best-known role is to act as a messenger carrying instructions from DNA for making proteins, the RNA types found in this study have diverse and complex functions. The team focused on “cell-free” RNA, found outside of cells in the liquid portion of blood, called plasma. Differences in the amount of certain cell-free RNA molecules identified patients with colorectal adenomas from those without. Colorectal adenomas are the type of colon polyp that can turn into cancer.
The patients in the study were a diverse group, representing nearly equal numbers of men and women mostly over 50 years old, with some younger patients as well. In addition, about 30 percent of the patients were African-American, which means the RNA measurement method described in the paper works nearly equally well for men and women of both African and European descent, across a range of ages.
In the short term, these findings won’t affect patient care, according to Richard Myers, president and science director at HudsonAlpha. The study was conducted in the Myers Lab at HudsonAlpha, where Myers is also a faculty investigator.
“There’s a lot more work to do before patients might see a test like this at the clinic, but we’re optimistic that with more research and after clinical trials, eventually, we will see blood-based screening for colon polyps and colon cancer itself offered routinely to patients,” Myers said.
Moving forward, the group is considering other physical markers that could be measured in blood, such as cell-free DNA, proteins or immune system measurements, that could add to the RNA signature found in their study. They are also looking to repeat the study in a larger patient population.
In addition to Roberts and Myers, HudsonAlpha researchers who worked on the study include Andrew Hardigan, Dianna Moore, Ryne Ramaker, Angela Jones and Greg Cooper.