1.P16INK4a: A Potential Diagnostic Adjunct For Prediction Of Highgrade Cervical Lesions In Liquid-Based Cytology: With HPV Testing And Histological Correlation
Yin Ping Wong ; Sayyidi Hamzi Abdul Raub ; Ahmad Zailani Hatta Mohd Dali ; Fauziah Kassim ; Vicknesh Visvalingam ; Zubaidah Zakaria ; Muhammad Amir Kamaluddin ; Sharifah Noor Akmal
The Malaysian Journal of Pathology 2016;38(2):93-101
Human papillomavirus (HPV) is a necessary cause of cervical cancer and its precursors. Increased
expression of high-risk hrHPV viral oncogenes in abnormal cells might increase the expression of
p16INK4a. We aimed to determine the role of p16INK4a in detecting hrHPV-transformed epithelial
cells in liquid-based cervical cytology, and compared the results with hrHPV DNA testing by realtime
polymerase chain reaction (RT-PCR). Fifty-seven cytological samples were tested for p16INK4a
immunomarker and hrHPV DNA. Test performance of both tests was determined by comparing
sensitivity, specificity and predictive values using available histological follow-up data as gold
standard. Of 57 samples, 36 (63.2%) showed immunoreactivity for p16INK4a and 43 (75.4%) were
hrHPV-infected. A fairly low concordance rate (k = 0.504) between p16INK4a immunolabelling
and hrHPV DNA status was noted. For prediction of cervical intraepithelial neoplasia (CIN) II and
worse lesions, p16INK4a had a sensitivity and specificity of 93.5% and 60%; whereas hrHPV DNA
testing had a sensitivity and specificity of 100% and 20%. Dual testing by combining p16INK4a
and hrHPV showed sensitivity and specificity of 100% and 33.3%. In conclusion, p16INK4a is
useful in predicting severity of the cytological abnormalities. Although p16INK4a is more specific
but less sensitive than hrHPV in detecting high-grade cervical lesions, a combination of both tests
failed to demonstrate significant improvement in diagnostic sensitivity, specificity and predictive
value. Larger-scale prospective studies are required to assess further whether this biomarker should
be routinely used as primary screening tool independently or in combination with hrHPV testing to
improve diagnostic accuracy in cervical cytology.