Genomic Test Improves Lung Cancer Diagnosis
Combination of test and bronchoscopy provided 94% diagnostic accuracy (Oct. 23)
A prospective clinical trial has demonstrated the diagnostic accuracy of a genomic test (BronchoGen, Allegro Diagnostics) in combination with bronchoscopy in diagnosing lung cancer. The study results were presented at the 78th annual meeting of the American College of Chest Physicians (CHEST), held October 20–25 in Atlanta, Ga.
The AEGIS I (Airway Epithelium Gene Expression In the DiagnosiS of Lung Cancer I) trial was a prospective, case-controlled, multicenter study designed to evaluate the prediction accuracy of the BronchoGen genomic test compared with and in combination with bronchoscopy. All of the patients were current or former smokers undergoing bronchoscopy for suspicion of lung cancer. Study endpoints included the sensitivity, specificity, negative predictive value (NPV), and positive predictive value of the BronchoGen test for identifying patients with malignancy.
Data were analyzed from a total of 330 patient samples — 240 patients with confirmed cancers and 90 controls. Microarray analysis was performed to identify genes associated with lung cancer, and a prediction model was developed. The test was converted to a reverse transcriptase polymerase chain reaction (RT-PCR) platform to validate the genes discovered on microarrays.
The PCR-based test yielded a sensitivity of 77% and a specificity of 73%. When the gene test was combined with results from bronchoscopy, the sensitivity of detecting lung cancer was 94%, compared with a sensitivity of 74% for bronchoscopy alone. Further, the NPV of the combined test was 0.85, compared with an NPV of 0.65 for bronchoscopy.
According to the test’s manufacturer, the molecular testing platform uses the gene expression of normal epithelial cells in the respiratory tract to detect early signs of lung cancer. The platform is based on the common molecular response that occurs throughout the respiratory tract in current and former smokers with lung cancer. These changes can be detected in a gene-expression signature from nonmalignant airway cells and indicate the presence of remote malignancy in the lung.
Source: Allegro Diagnostics, October 23, 2012.