Differences in CD44s expression in HNSCC tumours of different areas within the oral cavity

There is evidence of differences in p63 expression in HNSCC (head and neck squamous cell carcinoma) tumours of different sub-sites within the oral cavity which appear to have an important role in CD44 regulation. The aim of this study was to investigate CD44 expression in HNSCC tumours in different areas of the oral cavity.

Formalin-fixed and paraffin-embedded oral squamous cell carcinoma specimens from 29 patients were investigated. Expression of CD44s was detected by immunohistochemistry with specific CD44 antibodies and analysed using the H-score. The samples were classified by anatomic location (tongue; floor of the mouth; gingiva and other group included hard palate, tonsils, naso- and oropharynx) and histological tumour grade (G1 and G2-G3). Fischer's exact test with a Bonferroni correction was used for the statistical analysis.

Positive immunostaining for CD44s in carcinomas of the tongue was significantly lower (0%) than that of the floor of the mouth (85%; P=0.003) or other group (100%; P=0.003). No statistically significant differences in CD44s expression were found for different histological tumour grades.

The results indicate that CD44 expression is strongly reduced in tongue tumours compared with other sub-sites within the oral cavity. This should be taken into consideration in assessing the prognostic value of CD44s in this tumour group.