P22 Cancer stem cell marker aldehyde dehydrogenase 1 expression in oral squamous cell carcinoma – An immunohistochemistry study

Abstract

Background Aldehyde dehydrogenase 1 expression (ALDH1) has been shown to be a cancer stem cell marker. This study aimed to evaluate the expression of ALDH1 in different grades of oral squamous cell carcinoma (OSCC), and to correlate expression with pathological outcomes such as tumor stage, lymph node and distant metastases. Methods Tissue sections cut from 45 archival blocks of OSCC were stained using an ALDH1 monoclonal antibody and expression was quantified by area percent of immunostaining and staining optical density using an image analyzer computer system. ANOVA test and Tukey’s post hoc test were used to evaluate statistical significance of difference between different grades or stages. Unpaired Student’s t test was used to evaluate significance of difference between lesions with and without lymph node metastasis. Results ALDH1 expression varied based on tumor histological grade and clinical stage, with significantly greater mean area percent of immunoexpression recorded in poorly differentiated lesions ( P Conclusions ALDH1 is involved in development of oral SCC. Its expression increases in more aggressive lesions suggesting a role in promoting the invasive and metastatic potential. Quantification based on area percent of immunoexpression may yield more accurate findings compared to evaluation of optical density.