Blood markers that would detect pancreatic cancer

Researchers funded by the National Institutes of Health (NIH) have developed a blood test to detect pancreatic ductal adenocarcinoma, one of the deadliest types of cancer. This new test could improve survival rates of the pancreatic cancerwhich is usually diagnosed in advanced stages, when therapy is less likely to be effective. The findings were published in Clinical Cancer Research.

In general, only approximately 1 in 10 pancreatic cancer patients survive more than five years since diagnosis. However, experts predict that by detecting and treating cancer at an early stage, survival would improve. Although early detection of cancer is key, there are currently no detection methods that allow it to be done.

In the study, scientists at the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, and the Mayo Clinic, Rochester, Minnesota, used a phased approach to analyze biomarkers in blood drawn from patients with pancreatic cancer and similar patients without pancreatic cancer. They included two blood biomarkers previously explored for this purpose: carbohydrate antigen 19-9 (CA19-9), used to monitor response to treatment in patients with pancreatic cancer, and thrombospondin 2 (THBS2), another previously used marker. None of these markers worked well as a screening tool. CA19-9 may be elevated in people with benign conditions such as pancreatitis and bile duct obstruction, while other patients do not produce it at all due to genetic factors.

By analyzing stored blood samples, the team found two new biomarker proteins that were elevated in the blood of patients with early-stage pancreatic cancer compared to healthy volunteers: the aminopeptidase N (ANPEP) and the polymeric immunoglobulin receptor (PIGR).

By combining ANPEP and PIGR with CA19-9 and THBS2, the four-marker panel successfully distinguished pancreatic cancer cases from non-cases in 91.9% of cases for all stages combined, with a false positive rate of 5% in non-cases. Similarly, in early-stage cancer (stage I/II), the four-marker test identified 87.5% of cases.

“By adding ANPEP and PIGR to existing markers, we have significantly improved our ability to detect this cancer when it is most treatable,” said the study’s principal investigator, Kenneth Zaret, Ph.D., from the Perelman School of Medicine at the University of Pennsylvania.

Importantly, the four-marker test successfully distinguished cancer patients from both healthy individuals and those with non-cancerous pancreatic conditions, such as pancreatitis.

“The findings of our retrospective study justify the conducting more testing in broader populationsespecially in people before they develop symptoms,” Zaret said. “These prediagnostic studies would help determine whether the test could be used as a screening tool for people at high risk of developing the disease based on their family history, genetic screening results or personal history of pancreatic cysts or pancreatitis.”