Effect of Impaired Lung Function on the Development and Progression of Endobronchial Premalignant Lesions

Background: Chronic obstructive pulmonary disease (COPD) and presence of endobronchial premalignant lesions (EPL) are individual risk factors for lung cancer (LC). However, effect of impaired lung function (ILF) on the natural history of EPL has not been explored. Patients and Methods: This study included 217 high-risk participants from a hospital-based LC surveillance cohort who underwent pulmonary function testing followed by bronchoscopy with endobronchial biopsies. Baseline histopathology diagnoses included 91 cases (41.9%) with squamous metaplasia (SM), 25 (11.5%) with squamous dysplasia (SD), 1 (0.5%) with in-situ carcinoma and 5 (2.3%) with invasive LC. Follow-up biopsies were obtained for 69 patients, and 16 (23.2%) patients demonstrated progression to a higher grade lesion. Regression models were used to evaluate the relationship between ILF and EPL. All the models were adjusted for age, gender and tobacco smoking. Results: Patients with FEV1% of <50% had 4.5 times greater risk of being diagnosed with an EPL [95% confidence interval: 1.93-10.80] and 8-fold greater risk of SD, compared to patients with FEV1% ≥80. COPD was associated with 2.7 and 4.8 times greater risk of SM and SD, respectively. The mean time to progression to a higher-grade lesion was shorter in COPD patients compared to patients without COPD (27 versus 50 months, p = 0.02). Conclusion: Our results indicate that ILF may be a predictor of prevalence and progression of EPLs among patients at high risk of LC. Therefore, spirometry can be a complementary pre-screening tool for identifying patients with EPL who need more intense LC surveillance.

Early Detection of Lung Cancer Using CT Scan and Bronchoscopy in a High Risk Population

Background: Computed tomography (CT) and bronchoscopy have been shown to improve the detection rates of peripheral and central lung cancers (LC), respectively. However, the performance of the combination of CT and bronchoscopy in detecting LC, in high-risk patients, is not clear. Patients & Methods: This prospective study included 205 high-risk patients with a history of at least 2 of the following risk factors: (1) heavy smoking;(2) aero-digestive cancer;(3) pulmonary asbestosis or;(4) chronic obstructive pulmonary disease. Patients were offered chest X-ray, sputum cytology, conventional white-light followed by autofluorescence beonchoscopy (WL/AFB) and low-dose spiral CT both at baseline and follow-up visits. Results: Seven patients (3.4%) were diagnosed with LC or carcinoma in-situ (CIS) at baseline: CT evaluation detected 5 LC/CIS, while WL/AFB evaluation also identified 5 LC/CIS, 2 of which were not detected on CT. Six (85%) of these baseline lesions were early stage (0/IA). The relative-sensitivity of CT with WL/ AFB was 40% better than CT alone. On four year follow-up, 20 patients (9.8%) were diagnosed with an LC/CIS. CT with WL/AFB detected 19 cases (95%), whereas CT alone detected 15 cases (75%). Conclusion: Bimodality surveillance with spiral CT and WL/AFB can improve the detection of early stage LCs among high-risk