Clinical prognostic indicators of high-grade pre-invasive bronchial lesions

Lung cancer arises from multistep genetic damage of bronchial epithelium, driving multifocal progressive dysplastic lesions. However, the risk of progression of high-grade pre-invasive bronchial lesions to cancer is poorly assessed. The purpose of this study was to better define the parameters that predict the outcome of these lesions. The current authors prospectively studied 27 patients with 31 histologically proven severe dysplasia (SD) and carcinoma in situ (CIS), with repeated bronchoscopy and endobronchial treatment. The influence of respiratory-cancer history, histopathological classification, tobacco consumption, and number of biopsies on the progression rate into cancer was studied. The actuarial progression rate to cancer was 17% at 1 yr and 63% at 3 yrs. A total of 11 cases of CIS progressed to invasive cancer, 17 were stable or regressed during the study, two with SD regressed and one progressed to invasive cancer. Progression of CIS appeared more frequent in lesions diagnosed as "questionable CIS". Persistence of smoking did not influence high-grade lesion outcome. The existence of synchronous lung cancer did not seem to impact on progression. The number of biopsies did not influence the outcome. In conclusion, the current study suggests that the outcome of high-grade pre-invasive lesions is not modified by the number of biopsies performed on these lesions. Careful pathological examination of these lesions and pathological revision seem necessary, since questionable cases have the worse progression rate.