Blood Test Differentiates Pancreatic Cancer from Pancreatitis

A blood test has been developed that uses a humanized antibody to identify pancreatic cancer but it does not react with chronic pancreatitis tissues.

The test, which detects levels of the PAM4 antigen in blood samples will be important because it has the potential to be used as an assay to only pick up pancreatic cancer or the potential risk pancreatic cancer.

The use of the immunoassay was studied by the scientists at the biopharmaceutical company, Immunomedics (Morris Plains, NJ, USA) in 120 patients who had been diagnosed with benign diseases of the pancreas. They found 24 (20%) were positive for the PAM4 antigen. The majority of these cases had been diagnosed with chronic pancreatitis, which is a risk factor for pancreatic cancer, and all had had an operation to remove part of the pancreas because of the severity of their disease or because they had had the disease for an extended period of time.

The study found that 64% of pancreatic cancer patients with early stage disease and 85% with advanced disease, which had metastasized and spread to other organs were found to have the PAM4 antigen which was detected by the monoclonal antibody clivatuzumab. This antibody is specifically reactive with pancreatic ductal adenocarcinoma (PDAC) and does not react with chronic pancreatitis tissues. The overall specificity was 80% with respect to benign pancreatic disease. When the investigators looked at the surgical specimens of those with the chronic pancreatitis, they found that the PAM4 was found only within pancreatic intraepitheral neoplasia lesions (PanINs), which are known to be precursors to pancreatic cancer, and not within the inflamed tissue.

Cynthia L. Sullivan, MS, MBA, President and Chief Executive Officer of Immunomedics, said, “We believe this blood test has the potential to become a companion diagnostic for our clivatuzumab directed radiation therapy we are developing for pancreatic cancer. The Phase Ib study of yttrium-90 labeled clivatuzumab has completed the enrollment of pancreatic cancer patients with two or more prior therapies.” The study was presented by David V. Gold, PhD, at the Annual Meeting of the American Association for Cancer Research held April 6 -10, 2013, in Washington DC (USA).

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