New Tool Shows Promise for Early Lung Cancer Screening
FRIDAY Oct. 8, 2010 -- A new diagnostic tool that looks for signs of early stage lung cancer in the lining of the cheek show some promise in preliminary research.
Called partial wave spectroscopic (PWS) microscopy, the novel screening approach functions as a kind of optical sweep of the cheek that makes use of the fact that cells located far from the site of an actual tumor undergo specific tell-tale changes in their molecular composition.
"The basic idea is that smoking not only affects the lungs but the entire airway tract," lead author Dr. Hemant K. Roy, director of gastroenterology research at NorthShore University HealthSystem in Evanston, Ill., explained in a news release from Northshore.
"By examining the lining of the cheek with this optical technology, we have the potential to prescreen patients at high risk for lung cancer, such as those who smoke, and identify the individuals who would likely benefit from more invasive and expensive tests versus those who don't need additional tests," Roy explained.
Roy and colleagues from Northwestern University report their observations online and in the Oct. 15 print issue of Cancer Research.
While lung cancer survival is predicated on early detection and early surgical intervention, there are currently no recommended screening methods specifically aimed at uncovering the disease at an early stage, the study authors noted.
That means that the majority of lung cancer patients -- 90 percent of whom are smokers -- are diagnosed at a late stage, contributing to a low survival rate of just 15 percent at five years. In fact, in the United States, lung cancer is the leading cause of cancer fatalities.
Enter so-called "biophotonics" technology tools, such as PWS.
Developed by a Northwestern researcher, PWS has enough cutting-edge sensitivity to be able to detect the kind of small cellular changes that indicate the presence of cancer down to the 20 nanometer level. The technique has already been tested in a successful effort to screen for colon cancer and pancreatic cancer, the study authors noted.
With that in mind, Roy's team tested the PWS screening method on 135 patients, nearly half of whom were lung cancer patients with a history of smoking. Among the others, just over one-quarter were smokers diagnosed with chronic obstructive pulmonary disease, and the rest were a mix of healthy smokers and nonsmokers.
After swabbing each patient's mouth, cheek cells were optically scanned. The team found that PWS was successful at accurately distinguishing between cancer patients and individuals without cancer more than 80 percent of the time -- a rate that the authors said is equivalent to that of screening methods used for other cancers.
If the technique continues to perform well under further testing, the study authors suggested, it could eventually be used as a pre-screening tool to detect those high-risk patients who would benefit from additional testing, such as CT scans.
Dr. Roy Herbst, chief of the section of thoracic medical oncology at the M.D. Anderson Cancer Center in Houston, described the study as "a very interesting use of the latest technology."
"Certainly lung cancer is a disease that more than half the time has already spread and is incurable," he noted. "So, if we could find it earlier it would be a huge advance."
"So, while this is still preliminary and not yet ready for use in the clinic, the work here suggests that you can use a modern tools to develop a noninvasive technique that can help find the disease earlier and determine who's at a greater risk for malignancy than others," Herbst said. "And that would allow us to intervene sooner, which of course would be very helpful."
For more on lung cancer screening and diagnosis, visit the U.S. National Cancer Institute.
Posted: October 2010