Ki-67 as a Biomarker in the Progression of Cervical Lesions: A Clinicopathological Correlation

Abstract

Introduction: Cervical carcinogenesis follows a spectrum from normal epithelium to cervical intraepithelial neoplasia (CIN) and eventually invasive carcinoma. Accurate grading of these lesions is critical for clinical management. Ki-67, a nuclear protein expressed during active cell cycle phases, reflects cellular proliferation and may serve as an effective marker for lesion severity.

Methods: A total of 65 cervical biopsy and hysterectomy specimens (CIN 1, 2, 3, and squamous cell carcinoma) were collected over a 2-year period. Routine histopathological examination was followed by immunohistochemical staining using anti-Ki-67 (clone MIB-1). Ki-67 expression was graded: score 0 (no staining), 1 (<10%), 2 (10–50%), and 3 (>50%). Scores 2 and 3 were considered positive. Correlations between Ki-67 expression and lesion grade were analyzed.

Results: Ki-67 expression showed a statistically significant correlation with lesion severity (p < 0.0001). CIN-1 and CIN-2 lesions demonstrated absent or low proliferation, while CIN-3 showed moderate Ki-67 expression. Squamous cell carcinoma exhibited the highest Ki-67 positivity with 72.2% (n=13) showing 10–50% expression and 27.8% (n=5) >50%. Ki-67 demonstrated a sensitivity of 67%, specificity of 96%, and overall accuracy of 88% in distinguishing malignant from premalignant lesions.

Conclusions: Ki-67 immunohistochemistry is a useful adjunct in grading cervical lesions. Its progressive increase across lesion stages reinforces its value as a diagnostic biomarker for assessing cellular proliferation and malignant transformation in cervical neoplasia.