A novel test for lung cancer uses inner cheek cells to identify the disease in high-risk patients.
In a new study presented at CHEST 2005, the 71st annual international scientific assembly of the American College of Chest Physicians (ACCP), scientists found that buccal mucosa, or cells scraped from the inner part of the cheek, may contain information that separates patients with lung cancer from high-risk negatives, a finding that may support cheek cell analysis as a simple and inexpensive early screening method for patients at risk for lung cancer.
"Previous research has shown that cell nuclear changes can extend a significant distance from the site of a malignancy. We have already conducted a successful clinical trial for our sputum test for lung cancer. New data suggest that the effects of lung cancer can also be measured as far away as skin cells in the mouth," said lead researcher Bojana Turic, MD, Director of Clinical and Regulatory Affairs, Perceptronix, Inc, Vancouver, BC, Canada. "Although a clinical test based on buccal cells is still in development, the method of analyzing cheek cells to detect cancer is showing interesting results."
Dr. Turic and colleagues analyzed randomized cheek scrapings of 150 confirmed lung cancer patients and 990 high-risk patients, using Automated Quantitative Cytometry (AQC). Able to detect subtle changes in buccal cell nuclei, the AQC system analyzes several thousand cells per specimen and reduces the data to a single score that predicts the likelihood of the presence of cancer. Of the buccal specimens collected, the AQC showed 66 percent sensitivity at 70 percent specificity overall, and 61 percent sensitivity for stage I lung cancer, which comprised 47 of the 150 cases.
"Stage I lung cancer is considered treatable, but most lung cancers are currently detected beyond stage I," said Dr. Turic. "We believe that early detection is the key to reducing lung cancer mortality and have focused our approach around detecting stage I lung cancer."
Although the test is not intended for screening the general population, researchers are hopeful that the AQC method will become an accurate, noninvasive, inexpensive, and easy-to-administer lung cancer detection test for patients at risk for lung cancer.
"A sufficient amount of cells can be collected by scraping the inside of the cheek with a small wooden spatula similar to a tongue depressor," said Dr. Turic. "Ultimately, this test could be administered in primary care settings or dental offices. The procedure is simple enough that specimen collection could be done by patients themselves." Researchers stress that additional clinical testing of the AQC method is needed, using a sufficient number and appropriate sample of patients in order to validate the test's performance.
Researchers have also developed a sputum test that utilizes the AQC method. They hope to receive Canadian regulatory approval in early 2006. Both tests are intended to provide pulmonary physicians with valuable information to help them manage patients at risk of developing or suspected of having lung cancer.
"Each year, great strides are made in the detection, diagnosis, and treatment of lung cancer," said W. Michael Alberts, MD, FCCP, President of the American College of Chest Physicians. "As with any new cancer screening or therapy, rigorous testing must be conducted in order to establish its safety and efficacy. Therefore, we must remain cautious but hopeful regarding new advances in their initial testing stages."