Combined biomarker test identifies benign pancreatic cysts with high accuracy
A combination of two biomarker tests differentiates benign serous cystic neoplasms from potentially malignant pancreatic lesions with “near perfect” accuracy, allowing patients who test positive to avoid additional screening and surgery, according to new research.
The test combines vascular endothelial growth factor A (VEGF-A), a protein associated with blood vessel formation that is upregulated in many tumors, and cyst fluid carcinoembryonic antigen (CEA), a protein associated with cell adhesion that is increased in individuals with certain cancers. In this study, testing for each of these proteins individually accurately differentiated serous cystic neoplasms (SCN) from other pancreatic lesions, but the combination was nearly as effective as gold standard pathologic testing.
“Every day, surgeons follow patients who have pancreatic cysts that have no risk of cancer but are still worrisome,” C. Max Schmidt, MD, PhD, FACS, professor of surgery and biochemical/molecular biology at Indiana University School of Medicine, said in a press release. “They perform surgery or conduct diagnostic tests just to make sure they’re not wrong. With VEGF-A and CEA, we believe we may have invented a test that can help that group of patients who don’t have a risk of cancer get off the testing cycle and avoid surgery which, in and of itself, has a risk of mortality or complications.”
To test the accuracy of these biomarkers, Schmidt and colleagues used an enzyme-linked immunosorbent assay to test for them in pancreatic cyst/duct fluid obtained from 149 patients who had their pancreatic cysts surgically removed and diagnosed by pathology.
VEGF-A alone differentiated SCN with 100% sensitivity and 83.7% specificity, and CEA alone performed with 95.5% sensitivity and 81.5% specificity. Together, the biomarkers performed with 95.5% sensitivity and 100% specificity, which would have enabled 26 patients with SCN to avoid unnecessary surgery, the researchers concluded.
“Many investigators are looking for biological markers to help them understand which pancreatic cysts go on to form cancers,” Schmidt said in the press release. “Our laboratory is doing that, but it’s also looking for markers to help determine which ones never have the chance of becoming cancers in the first place. These are benign, and they’re fooling us into thinking they could become cancers. If we can do that with confidence, we’ll find patients who can avoid potentially morbid surgery on the pancreas to remove something that never needed to be removed.”
Until the test is validated in large prospective studies and a central laboratory for cystic fluid analysis is established, Schmidt recommended “that pancreatic surgical programs send specimens to the Indiana University Health Pancreatic Cyst and Cancer Early Detection Center in Indianapolis.”
This research was initially presented at the Western Surgical Association 124th Scientific Session in November 2016, and has since been published in the Journal of the American College of Surgeons. – by Adam Leitenberger
Disclosures: The researchers report no relevant financial disclosures.