Spit Test

By Dan Gordon

Published Oct 1, 2006 12:00 AM

Oral cancer will be diagnosed this year in approximately 30,000 Americans, only half of whom will survive more than five years. But if the cancer is detected early, there is an 80–90 percent chance of survival.

"Oral cancer is a debilitating disease that, when not deadly, can result in profound facial disfigurement, speech impairment, and an inability to eat normally," says David T. Wong, the dental school's associate dean of research and a member of UCLA's Jonsson Cancer Center, who is leading the effort. "Our motivation in investigating the saliva signature for oral cancer was to create a simple yet highly accurate way to detect this disease early enough to aid in avoiding such outcomes."

But there's more at stake here. The dental school's diagnostics breakthrough is a telling demonstration of how dental practitioners are increasingly working more closely with patients and their M.D.s. The initial foray into salivary diagnostics carries the promise of a new era in which a wide range of diseases — such as breast cancer and type 2 diabetes — might be found simply, cheaply and more quickly, saving lives. "Being able to detect disease before clinical symptoms is seen as the Holy Grail in many areas of medicine," Wong says. "The ability to do so using noninvasive means is still a quest."

Scientists have long recognized that saliva contains the full complement of proteins, hormones, antibodies and other molecular substances frequently measured in standard blood tests to monitor health and disease, but they lacked the tools to analyze the fluid. But the advent of nanotechnology — ultra-tiny machines that read the simplest cell structure — is ushering in new ways to identify, collect, preserve and amplify genetic material and proteins, removing a big barrier to the undertaking.

In 2002, the National Institute of Dental and Craniofacial Research, part of the federal National Institutes of Health, invested $85 million in studies aimed at turning saliva diagnostic tests into a clinical reality. UCLA, one of seven institutions to receive funding, engaged in identifying the genetic changes that can be found in saliva at the outset of the disease process and developing the technology that will quickly and accurately analyze human saliva to determine whether these disease markers are present. The initiative included researchers from UCLA's Henry Samueli School of Engineering and Applied Science.