Detection of C-MYC oncogene translocation and copy number change in the normal-dysplasia-carcinoma sequence of the larynx by fluorescence in situ hybridization

The aim of this study was to determine the translocation and copy number change of the C-MYC gene in patients with laryngeal dysplasia and laryngeal squamous cell carcinoma (LSCC), and to evaluate the prevalence of such expression in relation to the normal-dysplasia-carcinoma sequence. Fluorescent in situ hybridization (FISH) was applied on formalin-fixed paraffin-embedded blocks of 93 laryngeal lesion specimens (14 normal epithelium, 15 mild dysplasia, 18 moderate dysplasia, 16 severe dysplasia, 9 carcinoma in situ, and 21 invasive carcinoma). C-MYC translocation was not observed in all laryngeal tissue. The high frequency for C-MYC copy-number increased (100%) in invasive carcinoma: 57.14% amplifications and 42.86% gains, and the positive rate of C-MYC amplification and copy-number change increased with the increasing severity of laryngeal lesions (P < 0.0001). The results suggest that C-MYC may be activated by gain/amplification in LSCC and precancerous lesions. Thus, C-MYC may play an important role in promoting LSCC progression, and early FISH detection of C-MYC may be exploited to set a screening test for laryngeal dysplasia. Diagn.Cytopathol. 2013. (c) 2012 Wiley Periodicals, Inc.