Saliva May Help Early Detection of Pancreatic Cancer

When you are fighting pancreatic cancer, the most lethal of all cancers, you need all the help you can get. A team from the University of California, Los Angeles, have introduced a possible new weapon to the battlefield: saliva as a diagnostic tool that may aid in early detection of the disease.

Pancreatic Cancer
The National Cancer Institute reports that an estimated 42,470 new cases of pancreatic cancer were diagnosed in the United States in 2009, and more than 35,000 patients died of the disease. Pancreatic cancer is the fourth leading cause of cancer death in America, and the lifetime risk of developing the disease is about one in 72 for both women and men.

One factor that makes pancreatic cancer so deadly is that its typical symptoms—abdominal pain and jaundice--do not appear until the disease is in an advanced stage. Fewer than 5 percent of people who are diagnosed with pancreatic cancer live for five years, according to the World Health Organization, and full remission is a rarity. Availability of an early detection tool would be a significant step in fighting the disease.

Pancreatic cancer is also difficult to fight because the cause is not known, although experts have identified some risk factors. They include smoking (cigarette smokers are 2 or 3 times more likely than nonsmokers to develop the disease), having diabetes, being African American, and having chronic pancreatitis (an inflamed pancreas). Some studies suggest a high-fat diet and exposure to certain chemicals also increase risk of developing the disease. However, many people who have known risk factors do not get the disease.

The UCLA Study
A team of investigators from the UCLA School of Dentistry, the David Geffen School of Medicine at UCLA, the UCLA School of Public Health, and UCLA’s Jonsson Comprehensive Cancer Center have shown that a salivary diagnostic tool may be helpful in identifying and fighting the disease.

In the study, the senior investigator, David Wong, DMD, DMSc, and his team studied the saliva in 90 subjects. When they analyzed altered gene expression, they identified four biomarkers that differentiated pancreatic cancer patients from people who had chronic pancreatitis or who were healthy with 90 percent sensitivity and 95 percent specificity.

Although the sample size was small, the researchers believe their findings “underscore the potential for salivary diagnostics to play a pivotal role in the detection of systemic cancers and diseases,” according to Lei Zhang, PhD, a co-first author of the study and an assistant researcher at the UCLA School of Dentistry Dental Research Institute.

The development of an early detection tool for pancreatic cancer could save thousands of lives. A saliva diagnostic tool could be a simple, safe, cost-effective, and noninvasive answer. The study’s authors are making plans to test the salivary biomarkers in a larger group of subjects in a multicenter study, and note that the possibility these biomarkers could identify very early-stage and perhaps even pre-invasive pancreatic cancer should be investigated.

SOURCES:
UCLA news release, Feb. 15, 2010
National Cancer Institute