Immunodiagnostic Test Predicts Progression of Pancreatic Cyst to Cancer

By using an immunodiagnostic test to detect the Das-1 antibody biomarker in fluid from pancreatic cysts, researchers were able to identify those cysts that were likely to become cancerous with 95% accuracy.

Although pancreatic cystic lesions (PCLs) are frequently and incidentally detected, it has been difficult to determine their risk of malignancy. Previous studies had indicated that in immunohistochemical and ELISA analyses of tissue and cyst fluid from pancreatic intraductal papillary mucinous neoplasms (IPMNs), the monoclonal antibody Das-1 identified those at risk for malignancy with high levels of specificity and sensitivity. Therefore, investigators at Washington University (St. Louis, MO, USA) used pancreatic cyst samples from a multicenter cohort to validate the ability of Das-1 to identify high-risk PCLs, in comparison to clinical guidelines and clinical features.

For this study, the investigators obtained cyst fluid samples of 169 PCLs (90 IPMNs, 43 mucinous cystic neoplasms, and 36 non-mucinous cysts) from patients undergoing surgery at four tertiary referral centers. Histology findings from surgical samples, analyzed independently and centrally re-reviewed in a blinded manner, were used as the reference standard. An ELISA with Das-1 was performed in parallel using banked cyst fluid samples.

The results of the analyses revealed that the ELISA for Das-1 identified high-risk PCLs with 88% sensitivity and 99% specificity, and 95% accuracy, at a cut-off optical density value of 0.104. In 10-fold cross validation analysis with 100 replications, Das-1 identified high-risk PCLs with 88% sensitivity and 98% specificity.

“Some cysts have the potential to become pancreatic cancer, so there is the thought that we should err on the side of caution and remove the cysts,” said first author Dr. Koushik K. Das, assistant professor of medicine at Washington University. “But pancreas surgery is complicated. It often requires removal of the spleen, portions of the stomach, small intestine, and bile duct. In an ideal world, we only would do surgery on people whose pancreatic cysts are likely to develop into cancer. As it is, we probably do not operate on some people who need surgery and sometimes do operate when cancer is not present because we are working with imprecise information. Many cysts, if not most, probably should be left alone. But we do that at our peril because we may miss individuals harboring cancer. If we had a better biomarker, we would not have to rely on imperfect clinical and radiographic information.”

The Das-1 ELISA study was published in the June 5, 2019, online edition of the journal Gastroenterology.

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