Objectives: 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.
Materials and methods: 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.
Results: 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.
Conclusion: 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.
Clinical relevance: Cyclin D1 expression and CCND1 amplification seem to have a prognostic value for OSCC. Further studies of HNSCC should always consider subanatomic genetic differences.