SESSION TITLE: Lung Cancer Diagnosis
SESSION TYPE: Original Investigation Slide
PRESENTED ON: Wednesday, October 28, 2015 at 02:45 PM - 04:15 PM
PURPOSE: Lung cancer screening with low-dose chest tomography (LDCT) has been demonstrated to reduce mortality from this disease. Preliminary reports have suggested that up to 1 out of 5 lung cancers may be CT occult but detectable via autofluorescence bronchoscopy (AFB) which is known to improve the sensitivity for detection of preinvasive lesions in the central airway. We evaluated the prevalence of CT occult invasive and high grade preinvasive lesions in high risk subjects undergoing both AFB and LDCT screening for lung cancer.
METHODS: 2,537 subjects who had 2% or greater lung cancer risk over 3 years using a risk prediction tool were recruited from 8 centers across Canada in the Pan-Canadian Early Detection of Lung Cancer Study (2008-2011). The first half of these subjects received AFB in addition to CT (n=1300). We determined the prevalence of CT and AFB abnormalities and analyzed the association between selected predictor variables and dysplasia and carcinoma in situ (CIS) lesions, using univariate and multivariate logistic regression models.
RESULTS: Among 1300 subjects who underwent AFB, a total of 776 endobronchial biopsies were performed in 333 (25.6%) subjects. Dysplastic or higher grade lesions were detected in 5.2 % of the subjects [n=68; mild dysplasia (n=36), moderate dysplasia (n=25), severe dysplasia (n=3), CIS (n=1), carcinoma (n=3)]. Fifty six prevalence lung cancers were detected by LDCT. No invasive lung cancers were CT occult, although one case of CIS and 3 high grade pre-neoplastic lesions were detected by AFB alone. In the univariate models, significant risk factors for the presence of dysplastic (any grade) lesions or CIS included: lung cancer risk index; male gender; weight; and pack-years. In the fully adjusted model, male gender [Odd Ratio (OR) (95% CI)] 3.49 (1.50-8.13), pack-years 1.01 (1.00-1.03), and weight 1.02 (1.00-1.05) were significant independent predictors of dysplasia/CIS lesions.
CONCLUSIONS: Application of AFB in addition to LDCT in a high lung cancer risk cohort does not lead to an increased lung cancer detection rate.
CLINICAL IMPLICATIONS: Broad use of AFB as a screening tool in subjects at high risk of lung cancer does not appear justified given our findings and an overall decrease in the prevalence of squamous cell carcinoma.
DISCLOSURE: The following authors have nothing to disclose: Alain Tremblay, Niloofar Taghizadeh, Annette McWilliams, Paul MacEachern, David Stather, Kam Soghrati, Serge Puksa, Kazuhiro Yasufuku, Kayvan Amjadi, Simon Martel, Francis Laberge, Michael Johnston, Ming Tsao, Diana Ionescu, Stefan Urbanski, David Hwang, Jean-Claude Cutz, Harmanjatinder Sekhon, Christian Couture, Zhaolin Xu, Martin Tammemagi, Sukhinder Atkar-Khattra, Stephen Lam
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