1. Classifying Anal Intraepithelial Neoplasia 2 Based on LAST Recommendations.
- Author
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Liu, Yuxin, McCluggage, W Glenn, Darragh, Teresa M, Zheng, Wenxin, Roberts, Jennifer M, Park, Kay J, Hui, Pei, Blakely, Morgan, Sigel, Keith, and Gaisa, Michael M
- Subjects
Cancer ,Anus Neoplasms ,Biomarkers ,Tumor ,Biopsy ,Cyclin-Dependent Kinase Inhibitor p16 ,Female ,Humans ,Papillomaviridae ,Papillomavirus Infections ,Squamous Intraepithelial Lesions ,Uterine Cervical Neoplasms ,Interobserver agreement ,Human papillomavirus ,Anal intraepithelial neoplasia 2 ,p16 Immunohistochemistry ,Medical and Health Sciences ,Pathology - Abstract
ObjectivesThe Lower Anogenital Squamous Terminology (LAST) recommendations classify human papillomavirus-associated squamous lesions into low- and high-grade squamous intraepithelial lesions (LSILs/HSILs). Our study aimed to assess interobserver agreement among 6 experienced pathologists in assigning 40 anal lesions previously diagnosed as anal intraepithelial neoplasia 2 (AIN 2) to either HSIL or non-HSIL categories.MethodsAgreement based on photomicrographs of H&E alone or H&E plus p16 immunohistochemistry was calculated using κ coefficients.ResultsAgreement was fair based on H&E alone (κ = 0.42; 95% confidence interval [CI], 0.34-0.52). Adding p16 improved agreement to moderate (κ = 0.55; 95% CI, 0.54-0.62). On final diagnosis, 21 cases (53%) had unanimous diagnoses, and 19 (47%) were divided. When designating p16 results as positive or negative, agreement was excellent (κ = 0.92; 95% CI, 0.83-0.95). Among variables (staining location, extent, and intensity), staining of the basal/parabasal layers was a consistent feature in cases with consensus for positive results (20/20). Of the 67 H&E diagnoses with conflicting p16 results, participants modified 32 (48%), downgrading 23 HSILs and upgrading 9 non-HSILs.ConclusionsAlthough p16 increased interobserver agreement, disagreement remained considerable regarding intermediate lesions. p16 expression, particularly if negative, can reduce unwarranted HSIL diagnoses and unnecessary treatment.
- Published
- 2021