Topoisomerase IIalpha (TopoIIa) A New Promising Marker for Early Detection of Laryngeal Squamous Cell Carcinoma: An Immunohistochemical Study

OBJECTIVE: the aim of this study is evaluation of Topo IIa expression in laryngeal squamous cell carcinomas and correlation of this expression with various clinicopathological parameters. METHODS: ninety cases of laryngeal squamous cell carcinoma archived paraffin blocks were collected in the form of total laryngectomies. Each paraffin block was re-cut by rotatory microtome at 4 μm thickness and stained by hematoxylin and eosin for routine histopathological examination and on charged slides for immunohistochemistry using an automated staining system with antibodies against Topo IIa. Mainly nuclear and slightly cytoplasmic staining was considered positive. Percentage of positive Topo IIa cells was graded then grouped into low expression and overexpression. RESULTS: Topo IIa overexpression was seen in 91.1% of cases, while low expression was noticed in the remaining 8.9% of cases. There were statistically significant correlations between Topo IIa expression and tumor histological grade, lymph node metastasis and T stage as well as statistically significant positive correlation between Topo IIa expression as we progress from normal to dysplastic/in situ up to malignant transformation. CONCLUSION: High expression of Topo IIa may indicate more aggressive tumor and may play a role in tumorogenesis in laryngeal squamous cell carcinoma.