A simple nasal swab in patients suspected of having lung disease may have the potential to distinguish between benign and malignant lung lesions, according to a recent study by the Boston University School of Medicine (BUSM).
The new test, together with a patient’s clinical information, will help doctors identify those unlikely to have cancer, sparing them from costly, invasive procedures.
U.S. guidelines recommend lung cancer screening with computed tomography (CT) for current and former smokers aged 55 through 80 who smoked at least 30 pack-years and who have quit within the past 15 years.
But while nearly a quarter of high-risk screened subjects have a pulmonary lesion, 95 percent of them are ultimately diagnosed as benign, suggesting that most patients are receiving unnecessary invasive procedures.
A team led by BUSM medicine, pathology and bioinformatics professor Avrum Spira may have now developed an additional, non-invasive diagnostic approach that identifies patients likely to have benign disease — eliminating the need for invasive lung biopsies or other diagnostic procedures.
“Our group previously derived and validated a bronchial epithelial gene-expression biomarker to detect lung cancer in current and former smokers. This innovation, available since 2015 as the Percepta Bronchial Genomic Classifier, is measurably improving lung cancer diagnosis,” Spira, MD, MSc, the study’s corresponding author, said in a press release. “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.”
After examining nasal swabs from current and former smokers undergoing evaluation of pulmonary lesions suspected of lung cancer, the team found 535 genes that were differentially expressed in lung cancer patients compared to those with benign disease.
Restricting the analysis to 30 genes and combining them with patient data (age, smoking status, time since quit and mass size) showed high specificity and sensitivity in identifying those at low risk of having 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,” added Spira, who is also a pulmonologist at Boston Medical Center. “The ability to test for molecular changes in this ‘field of injury’ allows us to rule out the disease earlier without invasive procedures.”
Marc Lenburg, PhD, professor of medicine at BUSM and co-senior author, added that the results “clearly demonstrate the existence of a cancer-associated airway field of injury” that can be measured in nasal epithelium.
“We find that nasal gene expression contains information about the presence of cancer that is independent of standard clinical risk factors, suggesting that nasal epithelial gene expression might aid in lung cancer detection,” he said. “Moreover, the nasal samples can be collected non-invasively with little instrumentation or advanced training.”