The association between CD166 detection rate and clinicopathologic parameters of patients with colorectal cancer

Metastasis and recurrence of colorectal cancer after treatment is attributed to stem cells. The aim of this study was to determine the relationship between the expression of stem cell marker CD166 in colorectal cancer by immunohistochemistry and clinicopathologic parameters.

From 2006 to 2012, 121 colectomy specimens of patients with colon cancer that were operated in Babol Medical University in Iran were evaluated. The paraffin blocks were extracted from the archive and the slides were prepared and stained for H&E and Immunohistochemical (IHC) methods. The samples with cytoplasmic and/or membranous staining more than 50% of tumor cells were considered as positive. Pathological parameter including type of tumor, stage and grade, vascular invasion and location of the tumors were recoerded.

The mean age of the patients was 58.7±15.1 years. Sixty-four (54.9%) patients were males. Eighty-six (71.1%) subjects were positive for cytoplasmic and 42 (34.7%) for membranous and 42 (34.7%) for both cytoplasmic and membranous staining. The cytoplasmic expression of marker CD166 marker in mucinous type was 10 (50%) and was lower than non-mucinous type 76 (75.2%) (p=0.031). There was significant relationship between membranous expression of CD166 marker and tumor location (right colon in 23(54.8%), left colon in 18 (24.3%)] (p=0.001). There was no significant difference in the expression of marker with other demographic and clinicopathologic variables.

The results show that CD166 expression was seen in more than two-thirds of the patients. The cytoplasmic expression of CD166 marker was higher in non-mucinous type. The distributions of membranous expression of marker CD166 was related more in right colon with colorectal cancer.