Expression of topoisomerase II alpha, Ki-67 and p53 in early stage laryngeal carcinomas not featuring vocal cord fixation

Cytokeratin-17 as a Potential Marker for Squamous Cell Carcinoma of the Larynx

To assess cytokeratin-17 (CK17) as an immunohistochemical marker for squamous cell carcinoma of the larynx, we stained 63 tissue samples from 63 consecutive patients who were believed or suspected to have squamous cell carcinoma of the larynx for CK17 and analyzed them by computerized histomorphometry. The mean staining intensity for CK17 was significantly stronger (p < .01) in cancerous cells, dysplasia, and normal epithelium proximal to the tumor than in distal normal epithelium and polyps. The percentage of stained area, within samples taken from a single patient, was significantly higher in malignancy and dysplasia as compared to distal normal epithelium and in malignancy as compared to dysplasia and proximal normal epithelium (p < .001). The integrated optical density was significantly higher in the malignant epithelium, dysplasia, polyps, and proximal normal epithelium than in distal normal epithelium (p < .0001). We conclude that CK17 is a highly sensitive and specific immunohistochemical marker for premalignant and malignant transformation in the larynx. Further investigation is warranted in order to assess the role of CK17 in determining safe resection borders.

Expression of DNA topoisomerase II-α: Clinical significance in laryngeal carcinoma

DNA topoisomerase II-α (Topo II-α) is essential for numerous cell processes, including DNA replication, transcription, recombination, and chromosome separation and condensation. Altered Topo II-α expression may lead to carcinogenesis and cancer progression. The aim of the present study was to investigate the association between Topo II-α expression levels and clinicopathological data from laryngeal cancer patients. Immunohistochemistry was used to analyze Topo II-α expression in laryngeal squamous cell carcinoma and distant healthy tissues obtained from 70 patients. In addition, fluorescence in situ hybridization was used to detect Topo II-α amplification and chromosome 17 ploidy using a laryngeal cancer tissue microarray. The expression of Topo II-α protein was detected in 71.43% (50/70) of laryngeal carcinoma tissues, in contrast to 9% of healthy tissues (2/22). Furthermore, the expression of Topo II-α protein was found to be associated with tumor de-differentiation and advanced tumor T stage. However, the expression of Topo II-α protein was not identified to be associated with Topo II-α amplification in laryngeal carcinoma, although was found to positively correlate with chromosome 17 aneuploidy (P<0.05). A higher aneuploidy rate contributed to increased expression levels of Topo II-α protein. Aberrant Topo II-α expression and chromosome 17 aneuploidy contributed to the development and progression of laryngeal cancer, indicating that targeting Topo II-α may provide a treatment strategy for patients with laryngeal cancer.

DNA topoisomerase I and IIalpha expression in penile carcinomas: assessing potential tumour chemosensitivity

OBJECTIVE

To examine the tissue expression of DNA topoisomerase I (Topo I) and IIalpha (Topo II), to pursue the possibility of future chemotherapy regimens for squamous cell carcinoma of the penis (SCCP), as high expression of Topo I might indicate sensitivity to the camptothecins, whereas high Topo II might indicate sensitivity to etoposide.

PATIENTS AND METHODS

In all, 73 patients with SCCP were reviewed and then tissue samples microarrayed. These were then stained with immunohistochemistry for Topo I, Topo II and Ki-67. Tumour stage, grade and type were available.

RESULTS

Topo II showed a strong positive correlation with the proliferation index as measured by Ki-67 (P < 0.001) but no correlation with Topo I. There were also strong correlations between tumour grade and Ki-67, and Topo II expression (both P < 0.001). Tumour type was also strongly correlated with Topo II and Ki-67 expression, with the highest expression in basaloid carcinomas and the lowest in verrucous carcinomas. However, Topo I expression was not correlated with any other tumour variable.

CONCLUSION

The expression of Topo I is grade- and type-independent, and chemotherapy using the camptothecins is unlikely to be effective. The strong positivity of Topo II in high-grade and basaloid SCCPs suggests that treatment with etoposide or other Topo II 'poisons' might be a better target for future clinical trials.