Correlation between morphology and human telomerase gene amplification in bronchial brushing cells for the diagnosis of lung cancer

Abstract

The aim of this study was to investigate the frequency of amplification of the human telomerase gene (TERC), as measured by fluorescence in situ hybridization (FISH), in routine liquid-based cytological preparations from bronchial brushing specimens, and to assess the associations between TERC amplification, cytological diagnosis, and cytological morphology, in order to obtain further insight into these associations. Bronchial brushings from 102 patients with lung carcinoma (52 squamous-cell carcinomas, 22 adenocarcinomas, 28 small cell lung carcinomas) and 40 patients with nonmalignant disease were used. Amplification of TERC was performed using a commercially available two-color FISH probe, and slides were prepared for the SurePath liquid-based Pap test (LPT) using the same samples. Amplification of TERC was significantly associated with histological diagnoses (P < 0.05). Patients with lung cancer, and especially those with nonsmall cell lung cancer, had significantly higher percentages of cells with amplification of TERC than did patients with nonmalignant disease (P < 0.05). Comparing the FISH and LPT results, there was no significant difference in diagnostic sensitivity between the two methods (P > 0.05). However the difference in diagnostic sensitivity of the two methods for squamous-cell carcinoma was significant (P < 0.01). FISH can be performed on bronchial brushing specimens to detect amplification of TERC. This test may be an adjunct to cytology screening, especially in squamous-cell carcinoma, and may provide an indication of the potential of individual lesions to progress.