Estrogen receptor α and β, progesterone receptor, pS2 and HER-2/neu expression delineate different subgroups in ductal carcinoma in situ of the breast

Antiestrogen therapy of ductal carcinoma in situ (DCIS) has become a more common option in reducing risk of developing invasive cancer. Previously, estrogen receptor α (ER-α) was evaluated as the only predictive factor. Immunohistochemical staining was performed for ER-α, estrogen receptor ER-β, progesterone receptor (PR), pS2 and her-2/neu in 59 cases of ductal carcinoma in situ (DCIS). We observed a positive correlation between the expression of ER-α (p=0.003), PR (p<0.001) and histopathological grading. Of the DCIS, 61.5% of ER-β positive (p=0.046) and 35.5% of PR positive samples showed a coexpression with pS2, whereas 72.1% of pS2 negative DCIS were also negative for ER-β and 92.9% of PR negative DCIS were negative for pS2 (p=0.012). In contrast, 50.0% of her-2/neu negative DCIS expressed ER-6 receptor (p=0.052). We propose that there are subpopulations of DCIS which can be described by distinct endocrine-associated expression patterns.