Abstract: BACKGROUND ＆ AIM: To investigate the inactivation of Fhit gene in primary laryngocarcinoma, to discover the association of Fhit gene inactivation and the biological behavior of laryngocarcinoma, and the influence of environmental factors on Fhit gene. MATERIAL AND METHODS: RT_PCR was used to determine Fhit gene expression in the laryngocarnioma tissue and peripheral cancer tissue of 29 patients. If abnormal expression of Fhit gene was found, further sequencing was performed. We prepared the different profiles of Fhit gene expression in cancer tissue and non_cancer tissue, and in various clinical stages of laryngocarcinoma. Furthermore, we studied the effects of environmental factors (e.g. smoking and alcohol intake) on Fhit gene expression. RESULTS: Abnormal expression of Fhit gene was found in 22/29 cases. Among these, 4 did not express Fhit gene, and 18 had abnormal transcription of Fhit gene. There was a significant difference of abnormal Fhit expression between laryngocarnoma tissue and non_laryngocarnoma tissue (P<0.01). However, the abnormal expression of Fhit gene did not show significant difference during the different clinical stages of laryngocarcinoma (P>0.05). Between the smoking and non_smoking patiens, abnormal expression of Fhit showed significant difference (P<0.05). CONCLUSION： Abnormal expression of Fhit gene was a common event in laryngocarcinoma. Abnormal Fhit gene expression might be associated with oncogenesis of laryngocarcinoma, but did not worsen further with disease progression. Excessive smoking might result in structural change of the Fhit gene, and induce the occurrence of tumor.

Key words: laryngeal neoplasms, Fhit gene