EXPRESSION OF KI-67 AND ITS CORRELATION WITH ESTROGEN RECEPTOR, PROGESTERONE RECEPTOR, AND HER2/NEU STATUS IN BREAST CARCINOMA: A CROSS-SECTIONAL IMMUNOHISTOCHEMICAL STUDY

Abstract

Background

Ki-67 is a well-established marker of cellular proliferation and has emerged as an important prognostic biomarker in breast carcinoma. Its relationship with hormone receptor status and HER2/neu expression remains variable across populations.

Objective

To evaluate Ki-67 expression in breast carcinoma and determine its association with estrogen receptor (ER), progesterone receptor (PR), HER2/neu status, and clinicopathological parameters.

Materials and Methods

This hospital-based cross-sectional study included 52 histopathologically confirmed breast carcinoma cases. Immunohistochemistry was performed for Ki-67, ER, PR, and HER2/neu. Associations between Ki-67 expression and clinicopathological variables were analyzed using Chi-square and logistic regression analyses.

Results

Ki-67 positivity was observed in 29 of 52 cases (55.8%). Among Ki-67-positive tumors, high proliferative activity (>20%) was identified in 48.3% of cases. Ki-67 expression demonstrated a significant positive association with higher tumor grade (p=0.023) and significant inverse associations with ER expression (p=0.024) and PR expression (p=0.038). No significant correlations were observed with age, tumor size, lymphovascular invasion, lymph node status, combined ER/PR status, or HER2/neu expression. Univariate logistic regression revealed that Grade III tumors (OR=4.09, 95% CI: 1.25–13.36) and ER-negative tumors (OR=4.08, 95% CI: 1.27–13.13) were significantly associated with Ki-67 positivity.

Conclusion

Ki-67 expression is significantly associated with higher histological grade and hormone receptor negativity in breast carcinoma. Routine assessment of Ki-67 alongside ER, PR, and HER2/neu may enhance prognostic stratification and facilitate individualized therapeutic decision-making.