Value of estrogen receptor β expression in normal colon mucosa and colorectalcancer: an immunohistochemical analysis

Estrogens (ER) have a protective role against colorectal carcinoma (CRC). Reduction of death from CRC has been observed in women (30%) as compared to men (7%) in particular with the users of oral contraception and in those women treated with Hormone Replacement Therapy (HRT). The aim of this study is to analyze the expression of estrogen receptor β (ERβ) in normal colonic mucosa and in CRC. The archival material of formalin-fixed-paraffin embedded tissue sections of 10 cases of normal colonic mucosa and 25specimens of CRCwere utilized in this study. An immunohistochemistry using avidin-biotin immuno-enzymatic technique (ABT) for the expression of ERβ primary mouse monoclonal antibody was performed. ER is expressed in 3 out of 10 cases of normal colonic mucosa. CRC revealed different levels of ERβ expression regardless of patient age, gender, grade, invasion, or lymph node status. ERβpositive immunostaining is more common in well differentiated tumors and in lower stage of disease than in poor differentiated one and advanced stage of CRC. The immunopositivity of ERβ in CRC is seen in 56% of cases, whereas its negativity is 44%.