Salivary mRNA associated with pancreatic cancer

Digestive Disease Week 2008

Salivary mRNA biomarkers may detect pancreatic cancer at an earlier stage than other pancreatic cancer detection methods, according to data presented at Digestive Disease Week 2008.

James Farrell, MD, an assistant professor of medicine at University of California, Los Angeles, and colleagues conducted the study using saliva collected from patients with clinically confirmed pancreatic cancer, chronic pancreatitis and from healthy controls.

“Saliva has often been referred to as the ‘body’s mirror’ and thus has appeal as a non-invasive mechanism to detect disease,” Farrell said during his presentation. “This is not a new concept. Based on recent technologies that detect mRNA markers, we decided to evaluate the role of saliva to detect pancreatic cancer.”

In a gene-based assay of the saliva of 12 healthy controls and 12 patients with pancreatic cancer, the researchers found 181 mRNA markers that were significantly upregulated. They validated eight of these genes in an independent cohort. Five of the genes were previously reported.

The researchers then took an exon-based approach, which is a more detailed evaluation of mRNA. The saliva of 11 healthy controls and 8 patients with pancreatic cancer was evaluated. They performed a transcriptomic discovery using polymerase chain reaction, and they identified 190 exons that showed significantly increased upregulation.

The top 38 exons underwent further validation, where they confirmed a more than four-fold elevation of 22 of these exons. Fourteen of the exons were validated in a second independent cohort comparing the saliva of patients with pancreatic cancer with that of patients with pancreatitis and healthy controls.

Farrell said that they are currently working to validate all of the exon biomarkers in a new independent cohort. – by Emily Shafer

For more information:
Farrel JJ, Zimmerman B, Ammar A, et al. #317. Presented at: Digestive Disease Week 2008; May 17-22; San Diego.