A simple nasal swab may be able to detect lung cancer without painful, invasive biopsies. Researchers at Boston University School of Medicine (BUSM) found that a genomic biomarker in the nasal passage can accurately determine if a suspicious lung lesion is malignant.

Their findings, which appear in the Journal of the National Cancer Institute, will allow physicians to confidently identify patients who are at low probability for having lung cancer, thus sparing them from costly and risky procedures.

Current smokers, and many former smokers, are considered at high risk of lung cancer, and are encouraged to undergo chest imaging, including X-rays and computed tomography or CT. When suspicious nodules are spotted, unnecessary and invasive follow-up procedures, including surgical lung biopsy, are often performed on patients whose tumors are eventually found to be benign.

The Boston researchers had previously identified a biomarker in bronchial epithelial cells in current and former smokers. "This innovation, available since 2015 as the Percepta Bronchial Genomic Classifier, is measurably improving lung cancer diagnosis," said Dr. Avrun Spira.

"Given that bronchial and nasal epithelial gene expressions are similarly altered by cigarette smoke exposure, we sought to determine in this study if cancer-associated gene expression might also be detectable in the more readily accessible nasal epithelium," said Spira.

After examining nasal epithelial cells swabbed from current and former smokers undergoing diagnostic evaluation for pulmonary lesions suspicious for lung cancer, the researchers determined that the cells affected by lung cancer extended to the nose and could be a non-invasive biomarker to detect lung cancer.

"There is a clear and growing need to develop additional diagnostic approaches for evaluating pulmonary lesions to determine which patients should undergo CT surveillance or invasive biopsy," said Spira, who added that the discovery could allow doctors to rule out the disease earlier without invasive procedures.

Not only could a nasal swab test spare people with benign lesions from expensive and invasive tests, it could also help positively identify cancer earlier, essential for increasing a patient's chance of survival.

According to the American Cancer Society (ACS), people diagnosed with stage IV lung cancer have only a 1 percent chance of surviving for five years, and a 2016 British study found that approximately 70 percent of patients aren't diagnosed until their disease is advanced.

More than 224,000 new cases of lung cancer are diagnosed in the U.S. every year, and about 158,000 people die from the disease. According to the ACS, 1 out of 4 cancer deaths are due to lung cancer.