p16 Immunoreactivity Correlates With Morphologic Diagnosis of HPV-associated Anal Intraepithelial Neoplasia: A Study of 1000 Biopsies.

p16 is the most useful diagnostic marker for human papillomavirus (HPV)-associated anogenital lesions. In the cervix, the pattern of p16 immunoreactivity generally correlates with lesion severity. p16 expression in anal intraepithelial neoplasia (AIN) is far less studied. Whether such correlation holds true has to be determined. We correlated the degree and pattern of p16 immunohistochemistry (IHC) results with morphologic diagnoses of 1000 anal squamous and transitional zone biopsy specimens. Using the Lower Anogenital Squamous Terminology criteria, p16 IHC results were classified as block staining, partial staining, or negative. Among 150 samples without morphologic evidence of AIN, p16 was negative in 85% and partial staining in 15%. AIN 1 (n=400) revealed diverse results: 28% negative, 35% partial, and 37% block staining. Among AIN 2 (n=298), 89% were block, 9% partial staining, and 2% negative. AIN 3 (n=152) revealed block (95%) or partial staining (5%). For the detection of AIN 2/3, p16 block staining yielded 91% sensitivity, 73% specificity, 80% positive predictive value, 91% negative predictive value, and a Youden Index of 0.64. Combining block staining and partial staining slightly increased sensitivity (99%) and negative predictive value (98%), but significantly decreased specificity (43%), positive predictive value (59%) and Youden Index (0.42, P<0.001). As with the cervix, p16 immunoreactivity correlates with morphologic diagnoses of AIN. Block staining offers the optimal diagnostic value for AIN 2/3. Caution is required since AIN 1 frequently exhibits block staining; the prognostic value of p16 warrants further investigation.

Liu Y ，McCluggage WG ，Darragh TM ，Farhat N ，Blakely M ，Sigel K ，Zheng W ，Westra WH ，Gaisa MM ... -  《-》

P16 and Ki67 immunostaining is a useful adjunct in the assessment of biopsies for HPV-associated anal intraepithelial neoplasia.

Walts AE ，Lechago J ，Bose S 《AMERICAN JOURNAL OF SURGICAL PATHOLOGY》

Anal intraepithelial neoplasia: correlation of grade with p16INK4a immunohistochemistry and HPV in situ hybridization.

Bernard JE ，Butler MO ，Sandweiss L ，Weidner N ... -  《-》

Presence or Absence of Significant HPVE4 Expression in High-grade Anal Intraepithelial Neoplasia With p16/Ki-67 Positivity Indicates Distinct Patterns of Neoplasia: A Study Combining Immunohistochemistry and Laser Capture Microdissection PCR.

Leeman A ，Pirog EC ，Doorbar J ，van de Sandt MM ，van Kemenade FJ ，Jenkins D ，Quint WGV ... -  《-》

P16/CDKN2A and Ki-67 enhance the detection of anal intraepithelial neoplasia and condyloma and correlate with human papillomavirus detection by polymerase chain reaction.

Pirog EC ，Quint KD ，Yantiss RK 《-》