Evaluation of the Role of ALDH1 as Cancer Stem Cell Marker in Colorectal Carcinoma: An Immunohistochemical Study EC17-EC23
Dr. Nanis Shawky Holah,
M.D, Department of Pathology, Faculty of Medicine, Menoufia University, Shebien ElKom, Menoufia, Egypt.
Introduction: Colorectal Carcinoma (CRC) is the third most commonly diagnosed cancer in males. Stem Cells (SC) may be involved in tumour growth, including colon cancer. Aldehyde Dehydrogenase 1 (ALDH1) is a detoxifying enzyme that might modulate SC proliferation.
Aims: To evaluate the immunohistochemical expression of ALDH1 as stem cell marker in the pathogenesis of colorectal carcinoma.
Materials and Methods: This retrospective study included 71 colorectal specimens (49 colorectal carcinoma, 13 adenoma and 9 normal cases) that were collected from Pathology Department, Faculty of Medicine, Menoufia University during the period from 2011 to 2015. All cases were stained by ALDH 1 antibody. Survival data were available for 31cases.
Results: There was a statistical significant association between epithelial positivity of ALDH1 and younger age (p=0.003), right sided tumour (p=0.038), presence of lymph node invasion (p= 0.04), ulcerating gross picture (p=0.01) and presence of vascular invasion (p=0.05). Moreover, there was statistical significant association between stromal positivity of ALDH1 and smaller tumour size (p=0.03) and inverse association between stromal expression of ALDH1 and grade of tumour (p=0.000) and perineural invasion (p= 0.05). Furthermore, there was an inverse significant relation between CD44 and ALDH1 expression (p=0.001). Univariate recurrence free survival analysis revealed the bad prognostic impact of high grade (p=0.03) and female sex (p=0.02) on patient outcome.
Conclusion: Epithelial expression of ALDH1 might be associated with poor prognosis while its stromal expression might be associated with good prognosis.