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Genomic Test May Aid Lung Cancer Detection
A new test will allow patients suspected of having lung cancer to undergo fewer and less-invasive tests to determine if they have the disease.
Researchers have found that a genomic biomarker can accurately determine the likelihood of a lung lesion being malignant. The New England Journal of Medicine published findings online from two large, prospective, multicenter studies, Airway Epithelium Gene Expression in the Diagnosis of Lung Cancer (AEGIS) I and II. These findings support physicians’ use of the test to identify patients who are at low probability for having lung cancer, sparing them from costly and risky procedures.
“We are seeing an increase in the number of lesions suspicious for lung cancer found on chest imaging of current and former smokers. In the past, these patients have been subjected to invasive tests when traditional bronchoscopy tests prove inconclusive,” said senior author Avi Spira, MD, MSc, Professor of Medicine, Pathology, and Bioinformatics at Boston University School of Medicine (BUSM) and a co-developer of the test.
Previous work by Spira found that the pattern of gene activity in cells lining the upper respiratory tract can identify cancer that is developing deeper in the lung. “The ability to test for molecular changes in this ‘field of injury’ allows us to rule out the disease earlier without invasive procedures.”
The study involved 639 patients (298 in AEGIS I and 341 in AEGIS II) at 28 sites in the United States, Canada and Ireland who were undergoing bronchoscopy, a common nonsurgical procedure to assess lung lesions for cancer. Using airways cells collected by the bronchoscopy, the researchers found this genomic test, when evaluated with the bronchoscopy, had a combined sensitivity of 97% for detecting lung cancer, compared to 75% for bronchoscopy alone.
“This study validates the effectiveness of the bronchial genomic biomarker among those undergoing bronchoscopy in two independent groups. We found that it has high sensitivity across different sizes, locations, stages, and cell types of lung cancer,” added Spira. “The combination of the biomarker and bronchoscopy has a sensitivity of 96% and 98% in the AEGIS-1 and AEGIS-2 groups, respectively.”
The test, the Percepta Bronchial Genomic Classifier, is being developed by Veracyte, Inc. The 23-gene molecular classifier uses proprietary genomic technology to detect molecular changes that occur in the epithelial cells lining the lung’s respiratory tract in current or former smokers with lung cancer. These changes can be detected in cells obtained from standard cytology brushings taken during bronchoscopy from the mainstem bronchus and indicate the presence of malignancy or disease processes from distant sites in the lung.
An estimated 250,000 patients undergo a bronchoscopy for suspected lung cancer each year, with approximately 40% producing nondiagnostic results. This can lead to invasive procedures such as transthoracic needle biopsy or surgical lung biopsy that are risky and expensive.
“In intermediate risk patients with a nondiagnostic bronchoscopy, a negative genomic test warrants consideration of a more conservative diagnostic approach that could reduce unnecessary invasive testing in patients without lung cancer,” Spira said.
Sources: BUSM, May 17, 2015; and Veracyte Inc.; May 17, 2015.