[Fluorescence in situ hybridization combined with cytomorphology for the detection of lung cancer in bronchial brushing specimens].

ABSTRACT

Objective: To evaluate the diagnostic value of fluorescence in situ hybridization (FISH) combined with bronchial brushing cytology for detecting lung cancer. Methods: Centromeric enumeration probes (CEPs) for chromosomes 7, 8 and 17 were used in FISH assay. The combination of FISH and cytology was analyzed in 69 bronchial brushing specimens. Results: The positive rates of CEP7, CEP8 and CEP17 in malignant cases diagnosed by cytology were 50.0%, 80.8% and 65.4%, respectively. CEP8 probe showed significantly higher positive rate than CEP7 (P=0.015). In the samples of suspicious of malignancy, the positive rates of CEP7, CEP8 and CEP17 were 46.6%, 66.7% and 58.8%, respectively. While in atypical cases, the positive rates of these three probes were 20.0%, 33.3% and 25.0%, respectively. There was no statistical difference between suspicious of malignancy and atypical cases (P>0.05) as well as between malignant and suspicious of malignancy (P>0.05). No chromosome aberrations were found in normal cases diagnosed by cytology. The positive rates of these three probes in adenocarcinoma (ADC) were slightly higher than those in squamous cell carcinoma and small cell lung cancer. However, only CEP8 probe showed statistically difference between ADC and small cell lung cancer (P=0.044). The combination of cytology and FISH using any one of the three-probe set (CEP7, CEP8 and CEP17) showed the sensitivity and specificity of 80.3% and 100.0%, while those of cytology were 54.1% and 100.0%, respectively. Conclusions: FISH combined with cytomorphology assisted the cytology diagnosis of suspicious of malignancy and atypical cases. Therefore, it significantly improved the diagnostic sensitivity for lung cancer without sacrificing specificity.