Mesothelin is a protein normally found on mesothelial cells that line body cavities. Several types of cancer cells make large amounts of the protein that then circulates in the blood. Scientists examined whether elevated blood levels of mesothelin could be used as a biological indicator for pancreatic disease.

In a study of patients with pancreatic adenocarcinoma conducted at the Siteman Cancer Center at Barnes-Jewish Hospital (St. Louis, MO, USA) and Washington University (St. Louis, MO, USA), mesothelin in the blood was significantly higher in 73 of 74 cancer patients when compared to healthy people. Published this month in the November 1, 2009 edition of Clinical Cancer Research, the study also examined whether the protein could be useful for immune-based cancer treatments.

Pancreatic adenocarcinoma, the most common type of pancreatic cancer, strikes about 40,000 Americans per year. However, it is often not diagnosed until advanced stages of the disease because symptoms are nonspecific or completely absent. Less than five percent of patients survive more than five years after diagnosis.

"If we can turn on the immune system to attack cells that have mesothelin, that might become an important part of pancreatic cancer therapy," said cosenior author William G. Hawkins, M.D., a pancreatic cancer surgeon with the Siteman Cancer Center at Barnes-Jewish Hospital and Washington University. "Because mesothelin aids tumor growth, loss of mesothelin could make cancer cells behave more like normal cells. That means even if immunotherapy only knocked out the mesothelin in pancreatic cancer cells instead of killing the cells, it could still be effective. That's what's so exciting about mesothelin as a therapeutic target."

Related Links:
Siteman Cancer Center at Barnes-Jewish Hospital
Washington University