Role of p16/Ki-67 Dual Immunostaining in Detection of Cervical Cancer Precursors.

Background: Pap-smears-based cytology and human papilloma virus testing have their own limitations in detecting cervical precancerous lesions, and still need further standardization. Co-expression of p16ink4a and Ki-67 can be used as additional biomarker.

Aims: To study the role of liquid-based cytology and the dual immunostaining for p16/Ki-67 in predicting the presence of significant lesion in cases of mild cytological atypia.

Materials and Methods: A prospective, cross-sectional study was performed in the Department of Pathology, in collaboration with Department of Obstetrics and Gynecology over 15 months including 545 patients. Immunocytochemistry followed by colposcopy-guided biopsy were performed in 52 cases with epithelial abnormalities.

Results: Thirty-five cases (67%) were dual-stain positive among the cases with epithelial abnormalities. In the ASC-US and LSIL group, the sensitivity and specificity of the immunostaining in diagnosing CIN2+ lesions were 100 and 70% and 87.5 and 100%, respectively. p16/Ki-67 positivity also increased with cytological severity which in turn corresponded with histological findings: it reached from 33% in ASC-US to 100% in both HSIL and SCC categories.

Conclusion: This dual immunostaining may potentially be a useful tool in the triage of the ASC-US and the LSIL group, considering the high sensitivity and specificity values.