CCND1 amplification and cyclin D1 immunohistochemical expression in head and neck squamous cell carcinomas

Abstract

Gene products, which show a significant association to cell proliferation and cell cycle control, are of high scientific interest, because genes as well as gene products could be possible targets for a specific therapeutic approach and eventually be prognostic markers. Cyclin D1 expression and amplification as well as the Ki-67 expression status were examined in a two tissue microarray analysis for head and neck squamous cell carcinoma (HNSCC) including 546 patients. A tumour site-specific analysis and a survival analysis of 222 oral squamous cell carcinoma (OSCC) patients were performed. Cyclin D1 amplification status was examined with fluorescence in situ hybridisation analysis, while cyclin D1 expression and Ki-67 expression status were examined with IHC. Amplification of the CCND1 gene and immunohistochemical expression of cyclin D1 and Ki-67 were examined in 546 tumours of the head and neck region in two tissue microarrays. CCND1 amplification was significantly more frequent in pharyngeal carcinomas (63%) than in laryngeal (37%) and oral (25%) carcinomas. Among the 222 cases of OSCCs, both CCND1 amplification and cyclin D1 expression were significantly associated with overall survival of the patients (p = 0.0127 and p = 0.0004, respectively). Ki-67 expression was significantly associated with cyclin D1 expression and with amplification of the CCND1 gene (p = 0.0002 and p = 0.0015, respectively) but not with patient overall survival. Our results suggest the prognostic value of CCND1 amplification and cyclin D1 expression for patients with OSCC and highlight the genetic differences in HNSCC of different subanatomic localisation. Cyclin D1 expression and CCND1 amplification seem to have a prognostic value for OSCC. Further studies of HNSCC should always consider subanatomic genetic differences.