A study shows that a test using a monoclonal antibody to detect a cancer marker, the PAM4-protein, in the blood correctly identified nearly two thirds of patients with early stage pancreatic cancer. When combined with CA19-9, another tumor marker that is commonly used to monitor the course of the disease, the new test was able to detect 85 percent of patients with pancreatic ductal adenocarcinoma (PDAC), which makes up approximately 90 percent of all pancreatic cancers.

Based on the test's ability to correctly identify cancers already known in patients in the study, researchers say that the test may hold promise for early detection of pancreatic cancer in individuals at high risk for the disease. In addition, the test – in uncovering the PAM4-protein – opens up the possibility of personalized treatment for patients with pancreatic cancer with the use of PAM4-based imaging and therapy.

"Early detection, in addition to better therapeutics, is urgently needed for patients with pancreatic cancer," said lead author David V. Gold, PhD, director of laboratory administration and a senior member of the Garden State Cancer Center in Morris Plains, NJ. "Pancreatic cancer symptoms are vague, and the disease tends to develop and grow silently. By the time it is detected, it has often spread to other parts of the body, making it nearly impossible to cure. These study results are extremely encouraging and may eventually lead to improved detection of the disease in high-risk individuals."

Patients with early-stage pancreatic cancer have a five-year survival rate of approximately 22 percent, compared to only 1 to 2 percent for those with advanced disease. While the CA19-9 test is routinely used for monitoring pancreatic cancer progression, no test is currently approved by the U.S. Food and Drug Administration for detection and diagnosis of pancreatic cancer.

Gold and his colleagues previously developed the PAM4 blood serum-based test for the detection and diagnosis of PDAC. In earlier research, they demonstrated the test could identify 13 of 21 patients (62 percent) with stage 1 pancreatic cancer.

In the current study, the investigators expanded the research on the use of the PAM4-protein test to include 602 individuals, separated into four groups: patients with pancreatic cancer, including PDAC and other forms of the disease; those with cancers of the surrounding organs; patients with benign pancreatic disease, such as pancreatitis; and healthy adults.

The researchers found that the test detected 76 percent of individuals overall with PDAC, and 85 percent of such individuals when it was combined with the CA19-9 test. Among these, the test accurately detected 64 percent of patients with stage 1 disease, and 85 percent of individuals with advanced disease when the test was combined with the CA19-9 test. In cancers of surrounding organs, the investigators found that about half of patients with extrahepatic biliary (50 percent) and periampullary (48 percent) adenocarcinomas tested positive for the PAM4-protein. Gold said that the latter finding was not unexpected because these cancers originated in closely related organs.

For comparison, 19 percent of patients with benign pancreatic disease and 23 percent with chronic pancreatitis tested positive for the PAM4-protein. "These results demonstrate that reactivity of the PAM4 antibody is highly restricted to PDAC, with the biomarker present at the earliest stages of neoplastic development," Gold said. "To the best of our knowledge, there are no biomarkers or target antigens that are expressed at a similarly high frequency and concentration in PDAC, and which show such specificity."

In future research, the investigators plan to use the test to screen patients who are considered at high risk for pancreatic cancer – such as individuals with chronic pancreatitis, sudden onset diabetes or those with a family history of PDAC – for the presence of PDAC at an early stage of tumor growth.