Study on Immunohistochemical Cyclin D1 Expression and Flow Cytometric DNA Analysis in Squamous Cell Carcinoma of the Larynx

Do, Nam Yong; Jeon, Se Young; Na, Han Jo; Lee, Do Yong; Park, Sung Yong; Ma, Hyun Woong; Lim, Sung Chul

Abstract

BACKGROUND AND OBJECTIVES: Cancer is a disease characterized by deregulation of cell cycle control. During the last decade, many alterations in the signaling pathways that ultimately lead to DNA replication and mitosis have been identified in various tumor types. DNA analysis by flow cytometry is considered to be of prognostic value in squamous cell carcinoma of the head and neck. However, a few and contradictory studies have been made on squamous cell carcinoma of the larynx. Expression of the cell cycle control gene cyclin D1 may, at least in some tumor types, provide a prognostic marker. Cyclin D1 is expressed during the G1 phase of the cell cycle and becomes associated with its catalytic partner CDK4 or CDK6. The authors evaluated the prognostic significance of cyclin D1, DNA ploidy and S-phase fraction (SPF) in the squamous cell carcinoma of the larynx to determine their relationship with the various clinicopathological parameters.
MATERIALS AND METHODS
Paraffin embedded tissue specimens from 28 cases of squamous cell carcinoma of larynx were studied by the immunohistochemical method using cyclin Dl antibody and by flow cytometric DNA analysis. RESULT: The positive expression of cyclin D1 protein was 60.7% in squamous cell carcinoma of the larynx. In 28 cases of flow sytometric DNA analysis, 23 cases (82.1%) were diploidy and 5 cases (17.9%) were aneuploidy. The SPF ranged from 0.0% to 83.9% (mean 41.4, median 35.2). The mean SPF of DNA diploid cases was 34.2%, whereas that of DNA aneuploid cases was 74.7%. Expression of cyclin D1 protein was found in 52.2% of the diploid cases and in 100% of the aneuploid cases. This expression was statistically significant (p<0.05). Among the multiple factors, only the lymph node metastasis was found to be statistically significant in aneuploid cases and in higher SPF (> or = 35.2). The expression of cyclin D1 protein did not correlate with clinical features.
CONCLUSION
The expression of cyclin D1 protein may be related with development of squamous cell carcinoma of the larynx, but not correlated with prognostic indicators. In cases of aneuploidy/higher SPF (> or = 35.2), The expression of cyclin Dl protein did not significantly correlate with lymph node metastasis, but showed a high expression rate of cyclin Dl protein. However, these correlations were not sufficient for the prognostic indicators in squamous cell carcinoma of the larynx.