Researchers have developed a novel immunoassay for detecting early-stage pancreatic cancer that identifies and quantifies blood levels of the PAM4 protein - a unique antigen present in almost 90 percent of pancreatic cancers and precancers.

"Most patients with pancreatic cancer are diagnosed when the disease is advanced and more difficult to cure," said lead author David V. Gold, Ph.D., a member of the Garden State Cancer Center in New Jersey.

"In this study, we found that the PAM4 protein is quite accurate at identifying patients with pancreatic cancer and, if validated in larger studies, would be a promising tool for detecting this disease in its earlier, more treatable stages, before it spreads to other organs."

The PAM4 antibody (also called clivatuzumab) used in this assay reacts with a protein produced by pancreatic cancer cells. The protein is not detectable in normal pancreatic cells and is rarely detected in pancreatitis, a non-cancerous condition, making it highly specific for pancreatic cancer.

The researchers evaluated an immunoassay for the PAM4 protein in 68 patients who had pancreatic cancer surgery and 19 healthy controls. They found that the test was 62 percent sensitive for detecting stage 1 pancreatic cancer, 86 percent sensitive for stage 2 disease and 91 percent sensitive for stage 3/4 cancers. The assay was 81 percent sensitive for detecting all stages of pancreatic cancer.

The investigators concluded that these promising data warrant further evaluation to determine how the test can improve the management of patients with pancreatic cancer. If these results are confirmed, it may become possible to test people at risk for pancreatic cancer (patients with a history of tobacco use, or those with genetic or other medical factors) on a yearly basis, to enhance the chance of early detection.

Currently, just 7 percent of pancreatic cancer cases are detected at an early stage, before the cancer has spread to other parts of the body. The survival rate for stage 1 pancreatic cancer is 20 percent, compared with just 1.8 percent for those diagnosed when the disease has metastasized.

The investigators noted that the clivatuzumab antibody may also prove useful for treating the disease by acting as a carrier for agents (such as radioactive isotopes) that can target and kill cancer cells.