Circulating mesothelin serves as a marker of pancreatic cancer

3 November 2009

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Researchers have expanded on previous studies, and there may be a new weapon in the arsenal for immune-based strategies in treating pancreatic cancer – mesothelin protein. Findings also showed that circulating mesothelin is a marker of pancreatic disease.

According to research published in Clinical Cancer Research, a journal of the American Association for Cancer Research, the vast majority (99 percent) of patients with pancreatic adenocarcinoma have readily detectable circulating levels of the adenocarcinoma-associated protein mesothelin compared with barely detectable levels in normal healthy donor samples analysed.

Peter Goedegebuure, PhD, and colleagues at the Washington University School of Medicine in St. Louis, evaluated the presence of mesothelin in the serum of patients and examined the correlation of the mesothelin levels with the presence of pancreatic disease. Furthermore, they assessed if patients with pancreatic adenocarcinoma have increased anti-mesothelin immunity.

The researchers used immunohistochemistry (n=10 patients) and ELISA (n=81 patients) to evaluate levels of tumour cell-bound and soluble mesothelin, respectively in patients with pancreatic cancer.

Significantly elevated levels of circulating mesothelin protein were detected in 73 of the 74 patients with pancreatic adenocarcinoma, and in all five patients with benign pancreatic disease, but not in the healthy controls. This suggests that mesothelin is a marker of pancreatic disease, according to Goedegebuure. Furthermore, patients with pancreatic adenocarcinoma had a higher proportion of mesothelin-specific CD4 and CD8 T-cells compared to age-matched healthy controls (50 percent of patients vs. 20 percent of healthy controls).

"Mesothelin is an attractive target from a diagnostic and therapeutic perspective in patients with pancreatic cancer," said Goedegebuure, who is a research associate professor in the Department of Surgery. "Our findings call for additional studies to evaluate the usefulness of circulating mesothelin as a marker of pancreatic disease."

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