Ki-67 immunoreactivity in breast carcinomas in relation to transferrin receptor expression, estrogen receptor status and morphological criteria. An immunohistochemical study.

The number of proliferating cells was determined by Ki-67 antibody in 107 primary breast carcinomas. These results were compared with transferrin receptor (TrfR) expression, estrogen receptor (ER) status, histologic type, tumor grade, size and axillary lymph node status. The percentage of Ki-67-positive cells ranged from 0.9 to 26.4%. The proportion of Ki-67-positive cells was highest in medullary carcinomas. Immunoreactivity of Ki-67 in relation to TrfR expression showed significant correlation (p = 0.0001). An inverse relationship between ER status and Ki-67 positivity existed (p = 0.0001). 88 cases were subjected to histologic grading. There was a significant relationship showing an increase of Ki-67 immunoreactivity with decrease of tumor differentiation (p = 0.0001). The distribution of Ki-67 reactivity in relation to tumor size and nodal status of the axilla revealed positive correlations (p = 0.02; p less than 0.05). In conclusion, the use of Ki-67 monoclonal antibody as a marker for cell proliferation represents a method to get kinetic data inhering prognostic value.