Estrogen receptor beta expression in colitis‐associated carcinoma in comparison with sporadic colonic tumor: An immunohistochemical study

BACKGROUND AND AIM: The rate of ulcerative colitis (UC)‐related colorectal cancer (colitis‐associated carcinoma) is increasing. Estrogen receptor (ER) beta expression has been studied separately in patients with sporadic colorectal cancer and those with colitis‐associated carcinoma. However, no study has compared the expression in both of these cancer types. The present study aimed to evaluate the relationship between colitis‐associated carcinoma and ERs and assess whether the expression of ER beta influences cell proliferation. METHODS: This study included 45 surgically operated colitis‐associated carcinomas, 43 high‐grade dysplasias, 34 low‐grade dysplasias, 36 sporadic colorectal cancers, 44 high‐grade adenomas, and 34 low‐grade adenomas. ER beta expression was evaluated with immunohistochemistry. RESULTS: Colitis‐associated carcinoma showed significantly lower ER beta immunoexpression than sporadic colorectal lesions and high‐ and low‐grade dysplasia. In seven colitis‐associated carcinoma harboring both intensity score 3 (strong immunoexpression) and score 1 (weak immunoexpression) areas, the correlation among ER beta intensity, Ki‐67, and p21 labeling index was assessed; an area with an ER beta intensity score of 3 showed a higher Ki‐67 labeling index than that with score 1. In four out of the seven lesions, p21 labeling index was higher in the area of ER beta score 1 than in that of ER beta score 3. CONCLUSIONS: The data suggest that ER beta expression is an accelerating factor in colorectal tumors. This association may be lower in colitis‐associated carcinoma than in sporadic colorectal cancer.