P16, Ki67 and P63 Expression in Cervical Neoplasia: A Diagnostic Bridge Between Preinvasive and Invasive Lesions

Cervical cancer remains a leading cause of morbidity and mortality among women globally, especially in low- and middle-income countries (LMICs), where early detection and screening programs are limited. Immunohistochemical (IHC) markers such as p16, Ki67, and p63 have shown potential in enhancing diagnostic accuracy in cervical lesions. This study aimed to evaluate and compare the expression of these markers in preinvasive and invasive cervical lesions and correlate them with clinicopathological features.

A retrospective study was conducted on 209 histologically confirmed cervical biopsy specimens collected between 2016 and 2022. The cases included cervical intraepithelial neoplasia (CIN I-III), squamous cell carcinoma (SCC), adenocarcinoma, and poorly differentiated malignancies. Clinical data including age, symptoms, parity, and smoking history were reviewed. Immunohistochemistry for p16, Ki67, and p63 was performed, and expression patterns were statistically analyzed across different lesion grades.

CIN I (44.5%) and SCC (42.6%) were the most common diagnoses. The mean age increased with lesion severity (CIN I: 44.91 years; SCC: 51.14 years; p < 0.001). AUB and smoking were more prevalent in SCC cases (51.97% and 53.25%, respectively). P16 expression increased with lesion grade (Grade 3 in CIN I: 0%; SCC: 29.87%; p < 0.001). Ki67 showed high expression (2 + or 3 +) in 100% of SCC cases (p < 0.001). P63 expression was strong in all SCC and CIN III cases but absent in adenocarcinomas (p < 0.001).

The immunohistochemical markers p16, Ki67, and p63 demonstrate statistically significant expression patterns correlating with lesion severity and histological subtype. These biomarkers are valuable adjuncts in distinguishing low-grade from high-grade and invasive cervical lesions, supporting their use in routine diagnostic practice.