Cervix: Oral Abstract: Evaluation of biomarkers p16ink4a/ki-67 in cervical cytology for diagnosis of cervical intraepithelial neoplasia
This article was originally published by Wolters Kluwer - Medknow and was migrated to Scientific Scholar after the change of Publisher.
Novel biomarkers, P16INK4a/Ki-67 are disease specific and identify risk of progression to cervical cancer.
To test the clinical utility of biomarkers p16INK4a/Ki-67 in cervical intraepithelial neoplasia.
Experimental study was conducted over an 18 month period at a tertiary care hospital. 3500 sexually active women between 30-55 years were screened by VIA/VILI, Pap test & HPV-DNA PCR. All screen positive women (n=280) underwent colposcopy and biopsy if required. At the time of colposcopy repeat cervical smear were taken for evaluation of p16INK4a/Ki-67. Immunocytochemistry for p16INK4A and Ki-67 was done by partitioning one slide into two parts for each biomarker. For p16INK4A positivity, nuclear +/- cytoplasmic scoring and intensity score was calculated and final score obtained. For Ki-67 staining was exclusively nuclear. Staining patterns were categorized as negative, intermediate or strongly positive.
86 women with abnormal cytology were evaluated with p16INK4A/Ki-67 immunocytochemistry and 20.9% (n=18) and 18.6% (n=16) were positive for each biomarker. For ASCUS (n=42) and LSIL (n=23) smears, specificity and NPV were 100% with a likelihood ratio (LR+) of 27 and 25 respectively suggesting good diagnostic accuracy. The combined sensitivity and specificity of p16INK4a/Ki-67 in detecting CIN-2+ lesion was 76.9% and 95.8% respectively with LR+ of 18.72 in high grade smears.
p16INK4A/Ki-67 evaluation in cervical cytology are valuable biomarkers in ruling out or detecting CIN2+ in ASCUS and LSIL smears. Unnecessary intervention in large number of low grade smears can be avoided by applying these biomarkers. In high grade smears detection rate of biomarkers p16INK4A/Ki-67 was high and had a good diagnostic accuracy.