| Abstract: | Cell proliferation and estrogen receptor (ER) status was investigated in 45 invasive ductal carcinomas of the breast by immunohistochemical methods using monoclonal antibodies Ki 67 (anti-human proliferating cell antibody) and ER ICA. The results were assessed on the basis of nuclear staining intensity and the percentage of positively stained tumor cell nuclei (index score). There was a significant inverse correlation between the Ki 67 and ERICA index scores, although 4 cases showed high index scores for both markers. We conclude that ER positive cells do not always have low proliferation activity, which may be one of the reasons why endocrine therapy is not effective against all ER positive breast cancers. Acta Pathol Jpn 40: 902 907, 1990. |
