Expression of Aldehyde Dehydrogenase 1 in Patients with Colorectal Cancer in North of Iran

High cancer related mortality can be due to the presence of cancer stem cells (CSCs). Studies suggest aldehyde dehydrogenase (ALDH1) as a marker of CSCs. The aim of this study was to investigate its expression in colorectal cancer and also its association with clinicopathologic characteristics. In a retrospective study, patients with colorectal cancer attending Sari Imam Khomeini Hospital were enrolled. The intensity and distribution of ALDH1 expression in tumor and non-tumoral adjacent tissue samples were measured by immunohistochemistry. Data were analyzed using SPSS V18. Forty patients including 20 males and 20 females were studied. The frequency and intensity of ALDH1 expression in tumoral and non-tumoral tissues were not significantly different. The expression intensity was not related to age, type of adenocarcinoma, and tumor location, but it was found to be higher in women (P=0.08). Mild ALDH1 expression was higher in well-differentiated grade (P= 0.07). Discontinuous distribution was higher in non-mucinous adenocarcinoma (P= 0.06) and well-differentiated grade (P= 0.028). In this study, ALDH1 expression was not significantly different in the samples of colorectal cancer and normal adjacent. But, higher intensity of expression in women and discontinuous distribution were observed in well-differentiated and non-mucinous samples. The role of ALDH1 as a CSC marker in colorectal cancer requires further investigations.