Blood-Based Test May Detect Early-Stage Pancreatic Cancer

May 23, 2014
Anna Azvolinsky
Anna Azvolinsky

A blood-based test of four biomarkers including CA 19-9 may help clinicians diagnose pancreatic cancer at an earlier stage.

A blood-based test of four biomarkers including CA 19-9 may help clinicians diagnose pancreatic cancer at an earlier stage. The test correctly identified 92% of samples from patients with pancreatic cancer when compared with samples from healthy individuals. The test could also differentiate patients with cancer from those who have chronic pancreatitis or pancreatic cysts about 90% of the time.

These results were presented by study author Ayumu Taguchi, PhD, MD, assistant professor at the University of Texas MD Anderson Cancer Center in Houston, at a press conference for the American Association for Cancer Research (AACR) special meeting, Pancreatic Cancer: Innovations in Research and Treatment, held May 18–21 in New Orleans.

Only about 10% of patients with pancreatic cancer are diagnosed when their disease is localized to the pancreas, according to Taguchi, partly because of the difficulty of screening those at risk. Currently available imaging techniques such as ultrasound and magnetic resonance cholangiopancreatography (MRCP) can detect early-stage pancreatic cancer and pancreatic cysts, but these techniques are not feasible for screening large populations in terms of cost-effectiveness and invasiveness, Taguchi told Cancer Network. “Blood-based biomarkers would be ideal for screening of early-stage pancreatic cancer,” said Taguchi.

The known blood biomarker CA 19-9 is not reliable enough on its own to be used in a widely implemented test. For example, approximately 5% to 10% of people that have a fucosyltransferase deficiency do not have detectable CA 19-9 levels.

Initially, Taguchi and colleagues used samples from 98 pancreatic cancer patients, 29 patients with chronic pancreatitis, and 50 healthy individuals to narrow down potential biomarkers.

The four biomarkers were then validated in two additional cohorts: one group consisting of 42 early-stage pancreatic cancer patients, 50 healthy individuals, and 50 patients with chronic pancreatitis, and a second group of 22 early-stage pancreatic cancer patients and 14 patients with benign pancreatic cysts. CA 19-9 alone and the four-panel test correctly identified samples negative for pancreatic cancer in 78% and 94% of healthy individuals, respectively.

The study authors are planning to further validate their biomarker panel by using a large number of prediagnostic samples collected prior to patients’ diagnoses with early-stage pancreatic cancer. The team is also integrating potential biomarkers from different platforms, such as microRNAs or autoantibodies, according to Taguchi.

In February, we reported on a blood test that uses the levels of two panels based on microRNA to distinguish advanced pancreatic cancer patients from healthy individuals. These researchers also compared the use of the two panels with the measurement of levels of CA 19-9. This test is still being validated in patients with early-stage pancreatic cancer.

Clinical applications of an early-detection, blood-based test should include identifying those at high risk for pancreatic cancer, identifying those who need further imaging tests, and improving the diagnostic performance of the currently available imaging techniques, said Taguchi.