On improving early lung cancer detection and localization by automated image cytometry and autofluorescence bronchoscopy : a case finding study
Background: Conventional methods for early lung cancer detection as sputum cytology and white light bronchoscopy have a very low diagnostic rate not exceeding 40% and 29% respectively. Automated image cytometry and autofluorescence bronchoscopy are novel techniques developed to improve the diagnostic rate of such lesions with promising results. Objectives: Can an increase in the diagnostic rate of ELC be achieved by combining AIC with WLB/AF examination? Patients and Methods: In 1999-2000, 119 high-risk patients were recruited in 150 examinations in a case finding study. Initial investigations for presenting complaints were negative for lung cancer. All patients submitted airway secretion for AIC and conventional cytology (CY), underwent white light (WLB) and AF bronchoscopy. Suspected lesions were biopsied and examined histopathologically. Positive cases were followed up after 3 and 6 months. Results: Based on histopathology and/or cytology, 23 preneoplasias (16 cases of moderate to severe dysplasia and 7 carcinomata in situ) were diagnosed. Although the use of AF, the preneoplastic lesions were not localized in 3 cytologically diagnosed cases out of 23. A relative sensitivity of WLB/AF to WLB proved to be 1.8. The sensitivity of all methods proved to be 100% (23/23) for detecting all preneoplasia cases. After excluding 9 non-Compliant patients from follow up analysis, a success rate of 12/14 cases (86%) in treating preneoplasia was achieved. Conclusion: AIC of tracheobronchial secretions as well as AF are sensitive tools for the detection and localization of centrally located ELC lesions in a high-risk population. The complementary effect between both methods was represented as a 100% detection rate of all diagnosed preneoplasias. Recommendations: Patients with positive AIC or AF bronchoscopy without histopathological or cytological evidence of preneoplasia should be followed up carefully as they may harbor a yet morphologically undetectable ELC. The cut off points of 2cDI in the evaluation of preneoplasia may have to be redefined and differentiated from that for invasive cancer. The previously mentioned scheme for preneoplasia management proved a success rate of 86% in its treatment. AIC of tracheobronchial secretions and WLB/AF proved to be useful, rapid and accurate methods that should be highly effective, in combination with other complementary methods, as a screening tool in asymptomatic, high-risk patients.