Topoisomerase II alpha expression in squamous cell carcinomas of the head and neck

The aim of the present study was to examine topoisomerase II alpha (topo II alpha) expression in cancers of the head and neck and to Establish a corre lation with clinicopathological parameters and survival. Paraffin embedded tissue specimens (studied by immunohistochemistry), fram 103 consecutive pa tients with squamous cell carcinoma of the head cmd neck regions, were exam ined on the primary turner (96 patients) and on recurrence (7 patients), Im munostaining evaluation was quantified by examining at least 1,000 neoplast ic cells and counting the percentage of positively stained nuclei. Topoisom erase II alpha expression was correlated with age, gender, stage, site of t he disease tumor differentiation, response to chemotherapy, disease-free su rvival and overall survival. More than half of the specimens had a high exp ression of topoisomerase II alpha (greater than or equal to 15% positive ne oplastic cells). Topoisomerase II alpha expression was significantly higher in tumors of low and moderate differentiation versus tumors of high differ entiation (P = 0.00001). There was also a significant difference in topo II alpha in specimens of responders to chemotherapy versus non-responders (P = 0.02), although the cytotoxic drugs used do nor belong to topoisomerase I I alpha antagonists. The correlation of high topoisomerase II alpha express ion and stage of disease, age, gender, primary site, recurrence, disease-fr ee survival and overall survival was nor statistically significant. In conc lusion, topoisomerase II alpha is highly expressed in histological specimen s of the majority of patiehts with head and neck cancers; mainly, it is rel ated to a significant degree to low and moderately differentiated tumors ve rsus highly differentiated ones. High expression of topoisomerase II alpha is also significantly related to response to chemotherapy.