Abstract A22: Spirometric surveillance for premalignant and malignant bronchial lesions

Abstract

Abstract Background: Chronic obstructive pulmonary disease (COPD) and lung cancer (LC) are diseases that share common risk factors. It has been reported that more than half of the patients diagnosed with LC also suffer from COPD. Although COPD is a well known risk factor for LC, the relationship between impaired lung function (LF) and the incidence and progression of pre-malignant lesions (PMLs) in the central airways is still unclear. Methods: The study included 217 high-risk patients from a hospital-based lung cancer surveillance cohort who underwent bronchoscopy with endobronchial biopsy of suspicious lesions, at the Roswell Park Cancer Institute, Buffalo, New York. All patients had lung function measurement within 6 months preceding their baseline biopsy. Baseline histopathology diagnoses included 91squamous metaplasia (SM), 25 squamous dysplasia (SD), 1 in-situ carcinoma and 5 invasive bronchial carcinoma. Follow-up bronchoscopy and biopsy were performed on 69 patients. Sixteen patients had a progression of the baseline lesion to a higher grade. The relationship between the baseline LF measures and the incidence and progression of PMLs were examined using regression models. Results: Patients with forced expiratory volume in 1 second percent predicted (FEV1%) of <50% had 4.5 times greater risk of being diagnosed with PML/cancer, when compared to patients with FEV1% ≥80. Increased risk was noted for all grades of PMLs and cancers, with the risk being almost 8 times for squamous dysplasia [Odds ratio = 7.95; 95%confidence interval (CI) =1.77–35.6]. Similarly, FEV-1/FVC ratio of <50% was associated with 3 times greater risk of detecting a PML/cancer. When COPD was classified based on GOLD criteria, the patients with severe COPD had 2.7 times and 4.8 times greater risk of being detected with SM and SD, respectively. The risk persisted for SD even when an age standardized classification was used to define COPD. COPD patients also had a non-statistically significant 2.5 times greater risk of their baseline lesion progressing to a higher grade [Hazard Ratio 2.48 (95% CI 0.65 – 9.41), p-value - 0.18)]. The mean time to progression from a lower grade lesion to a higher grade was 27 months for patients with COPD and 50 months for patients without COPD. Conclusion: Impaired LF can be a good predictor of occurrence and progression of PMLs in central airways of high risk patients. Spirometric measurement of lung function can be used as an additional tool for identifying target populations in need of more aggressive LC surveillance. Citation Information: Cancer Prev Res 2010;3(1 Suppl):A22.