The four combined markers accurately identified 64 percent (sensitivity) of the pancreatic cancer cases and correctly identified 89 percent of those without disease (specificity). That degree of sensitivity and specificity are good for a pilot study but don't yet rise to the levels required for translation in the clinic, which would require investigating more circulating microRNAs in blood in a larger sample of persons representing different stages of the disease and healthy controls.

The study's small sample size, which compared only the extremes of pancreatic cancer or the complete absence of the disease, is a limitation, but the results justify continued development of this strategy, Sen said.

One of the miRNAs in the study is overexpressed in precursor lesions that can lead to full pancreatic cancer. "The fact that a microRNA reported to be overexpressed in pre-invasive pancreatic cancer could be detected in blood plasma from pancreatic cancer patients raises the possibility that a blood test for detecting pre-invasive pancreatic cancer may become a reality," Sen said.

Marker miRNAs used in the study were miR-21, miR-210, miR-155 and miR-196a.

Sen and colleagues are working with the Early Detection Research Network of the National Cancer Institute to develop studies with larger sample sizes that are designed to test miRNA markers associated with different grades and stages of the disease.

Source: University of Texas M. D. Anderson Cancer Center