Bronchoscopy is often the initial diagnostic procedure performed in patients with pulmonary lesions suspicious for lung cancer. A bronchial genomic classifier was previously validated to identify patients at low risk for lung cancer after an inconclusive bronchoscopy. In this study, we evaluate the potential of the classifier to reduce invasive procedure utilization in patients with suspected lung cancer.
In two multicenter trials of patients undergoing bronchoscopy for suspected lung cancer, the classifier was measured in normal appearing bronchial epithelial cells from a mainstem bronchus. Among patients with low and intermediate pretest probability of cancer (n=222), subsequent invasive procedures following an inconclusive bronchoscopy were identified. Estimates of the classifier’s ability to reduce unnecessary procedures were calculated.
Of the 222 patients, 188 (85%) had an inconclusive bronchoscopy and follow-up procedure data available for analysis. Seventy-seven (41%) patients underwent an additional 99 additional invasive procedures, which included surgical lung biopsy in 40 (52%) patients. Benign and malignant disease were ultimately diagnosed in 62 (81%) and 15 (19%) patients, respectively. Among those undergoing surgical biopsy, 20 (50%) were performed in patients with benign disease. Were the classifier used to guide decision making, procedures could have been avoided in 50% (21 of 42) of patients undergoing further invasive testing. Further, among 35 patients with an inconclusive index bronchoscopy that were diagnosed with lung cancer, the sensitivity of the classifier was 89%, with 4 (11%) patients having a falsely negative classifier result.
Invasive procedures following an inconclusive bronchoscopy occur frequently and the majority are performed in patients ultimately diagnosed with benign disease. Using the genomic classifier as an adjunct to bronchoscopy may reduce the frequency and associated morbidity of these invasive procedures.