RESUMEN
PURPOSE: The aim of the study is to investigate the immunohistochemical expression of both Alpha smooth muscle actin and Transforming Growth Factor beta and compare their expression in oral papillary squamous cell carcinoma with their expression in different histological grades of oral squamous cell carcinoma. A correlation between these immuno-histochemical expressions and histological findings will then be performed. The research question is "Do the percentages of α-SMA and TGF-ß immune-expression in OPSCC differ from that in the conventional OSCC?". METHODS: This will be achieved by collecting archival blocks of oral papillary squamous cell carcinoma and different grades of oral squamous cell carcinoma, staining the specimens with Transforming Growth Factor beta and alpha smooth muscle actin, then measuring the mean staining index of expression in each group and the area percent of both markers. RESULTS: Results revealed that transforming growth factor beta expression in the epithelium was high in all cases of well-differentiated squamous cell carcinoma, most oral papillary squamous cell carcinoma, and poorly differentiated oral squamous cell carcinoma. On the other hand, different grades of oral squamous cell carcinoma showed a high staining index of alpha smooth muscle actin expression in the stroma. While cases of oral papillary squamous cell carcinoma were either moderate or low-staining. CONCLUSIONS: Oral papillary squamous cell carcinoma has a favourable prognosis compared to different histological grades, and the prognosis does not depend only on histological grade but also on other prognostic factors.