[Evaluation of P16(INK4α) expression in Thinprep cervical specimens for the predication of high-grade cervical intraepithelial neoplasia].

OBJECTIVE

to explore the value of P16 in the predication of high-grade cervical intraepithelial (HGCIN) by P16 expression in cervical specimens.

METHODS

one hundred ninety-two residual ThinPrep samples were collected and detected by HPV DNA test and P16 detected by immunocytochemistry. All women underwent colposcopy and histological examination of biopsy specimen if needed. P16 test, cytology and HR-HPV DNA (HC2) test were compared based on histological examination of colposcopic biopsies.

RESULTS

(1) the expression of P16 showed 16.3% in normal or inflammatory cases, 46.7% in CIN 1, 93.8% in CIN 2, 91.1% in CIN 3 and 100.0% in carcinoma. A positive relation between P16 and the grade of cervical lesions was observed by Spearman analysis (P < 0.05, r = 0.900). (2) By P16 test, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for ≥ CIN 2 were 94.1%, 78.5%, 77.7%, 94.4% and 85.4% respectively. By HR-HPV DNA test, the sensitivity, specificity, PPV, NPV and accuracy for ≥ CIN 2 were 95.3%, 56.1%, 63.3%, 93.8% and 73.4% respectively. By cytological test, the sensitivity, specificity, PPV, NPV and accuracy for ≥ CIN 2 were 82.4%, 92.5%, 89.7%, 86.8% and 88.0% respectively. There were significant difference of specificity, PPV and accuracy between P16 and HR-HPV DNA (P < 0.05). And no significant difference of accuracy was found between P16 and cytology (P > 0.05).

CONCLUSION

the specificity, PPV and accuracy of P16 are significantly higher than those of HR-HPV DNA. Thus P16 test is valuable to diagnose HGCIN in ThinPrep specimens.