Detection Of P16 And FHIT Deletions In Tissues Obtained By Fiberoptic Bronchoscopy And Its Diagnostic Value Of Lung Cancer

Objective: To explore the deletions of P16 and FHIT in biopsy samples of fiberoptic bronchoscopy(FB) in patients with lung cancer and benign pulmonary diseases as an approach to early diagnosis of lung cancer and to investigate the role of their alterations in the genesis and development of lung cancer.Method: Reverse transcription polymerase chain reaction(RT-PCR) was used to examine the deletions at P16 and FHIT in 52 patients with lung cancer and 9 patients with nonmalignant disease.Results: Thirty-one of 52(65.4%) samples of patients with lung cancer and 1 of 9(11.1%) samples of patiens without lung cancer exhibited loss of P16 gene transcripts. Most deletion of P16 gene was loss of exon 2. The abnormity of P16 gene was not significantly associated with histological type, cell differentiation, clinical stage and metastasis of lung cancer. In stage I and II lung cancer, the obvious aberrancy of P16 gene was found.The deletion rate of FHIT gene was 65.4%(34/52) and 22.2%(2/9) in the tissues of lung cancer and benign disease, respectively. In 52 cases of lung cancer, the frequency of loss at FHIT exons 1 -4 was not significantly higher than that at FHIT exons 5-9. The loss of FHIT expression did not correlate with histological type, cell differentiation, clinical stage and metastasis, but was frequently observed in tobacco smokers. In the early stage of lung cancer, 61.1% of the cases showed a marked loss of FHIT gene.The sensitivities of P16 and FHIT deletion assay in biopsy samples of lung cancer were 59.6% and 65.4%, respectively, whileas the combined assayproduced a sensitivity value of 80.8%. In 10 cases of lung cancer patients whose pathologic examination of the bronchial biopsy samples were negative, 8(80%)were found P16 or FHIT abnormity.Conclusions: Losses of P16 and FHIT gene transcripts are frequent events in lung cancer. P16 and FHIT gene may play an important role in genesis and progression of lung cancer.Detection of P16 or FHIT gene deletions in biopsy samples of FB may be used to diagnose lung cancer. Combined examination of P16 and FHIT deletion can increased the sensitivity in diagnosis of lung cancer and is helpful for early diagnosis of lung cancers.