Differentiation of positive autofluorescence bronchoscopy findings by comparative genomic hybridization.

Up to 50% of the results of autofluorescence bronchoscopy (AF) of histologically benign lesions are false-positive. For better differentiation of such lesions we have used comparative genomic hybridization (CGH). We studied biopsy material from 47 patients by CGH. For a comparison of findings, the patients were grouped as follows: Group 1, patients with manifest malignant lesions (n=10); group 2, patients with positive autofluorescence and negative (benign) histology (n=16); group 3, patients with negative autofluorescence and negative histology, who belong to a typical high-risk group for lung cancer (n=21). The biopsy specimens of 21/47 patients (45%) showed chromosome aberrations. In 8/10 cases (80%) in group 1, one or several chromosome lesions were detected. Chromosome aberrations were found in 13/16 specimens (81%) taken in group 2. None of the 21 biopsy specimens from the patients of group 3 showed any chromosome lesions. The chromosome aberrations detected in groups 1 and 2 show nearly identical distribution patterns. Lesions of chromosome 3 are the most frequent ones in both groups. The results of the CGH investigation show that regions of the bronchial mucosa with positive AF finding and benign histology frequently are seriously damaged and may develop into potentially malignant lesions.