PURPOSE: Squamous cell Lung cancer (SLC) is the second most common lung cancer (LC) cell type, and the World Health Organization has classified metaplasia, dysplasia and carcinoma-in-situ (CIS), or Intraepithelial Neoplasia (IEN) as precursors to invasive SLC. COPD is an independent risk factor for LC, however the relationship between airflow obstruction and premalignant changes in the central airway are unclear.
METHODS: We used a hospital based surveillance cohort to analyze the relationship between spirometric parameters of airflow obstruction and central pre-malignant lung lesions. Subjects included individuals who visited LC screening clinics at Roswell Park Cancer Institute from 1996-2005. All these patients underwent simple spirometry with a hand-held spirometer according to ATS standards. 269 high-risk patients with COPD underwent autofluorescence bronchoscopy, with endobronchial biopsy of suspicious lesions. FEV-1% predicted and FEV-1/FVC ratio were correlated pathological diagnoses in a retrospective analysis; the relationship was examined using logistic regression technique and all the results were adjusted for smoking status.
RESULTS: 61 biopsies indicated normal bronchial epithelium, 56 biopsies confirmed the presence of squamous metaplasia, 29 confirmed squamous dysplasia and 123 confirmed either CIS or invasive central LC. We found that an FEV-1 % predicted of < 70% was associated with almost twice the risk of detecting any pre-malignant/malignant lesion [Adjusted odds ratio (AOR),1.87; 95%confidence interval(CI),1.03-3.39; p <0.04]. The FEV-1/FVC ratio of <70% was associated with 66% greater risk of detecting any pre-malignant/malignant lesion. An FEV-1% of <60% was associated with more than two times greater chance of detecting squamous metaplasia (AOR,2.32; p< 0.02) and almost twice the chance of squamous dysplasia or carcinoma. An FEV-1/FVC ratio of <65 was almost four times a better predictor of dysplasia (AOR,3.96; p-trend,0.05) and more than 2.5 times a better predictor of squamous metaplasia or worse (p < 0.007).
CONCLUSION: Air flow obstruction, determined by spirometry, appears to be a good predictor of pre-malignant lung lesions.
CLINICAL IMPLICATIONS: Spirometry is a potential marker for lung cancer surveillance using autofluorescence bronchoscopy.
DISCLOSURE: Gregory Loewen, None.