CK7 Immunohistochemistry as a Predictor of CIN1 Progression

Abstract

Cervical high-grade squamous intraepithelial lesion (CIN2-3) is thought to arise from a distinct population of cells at the squamocolumnar junction (SCJ). Immunohistochemical (IHC) biomarkers that characterize the SCJ phenotype, including CK7, have been proposed as tools to separate the subset of low-grade squamous intraepithelial lesions (LSILs) (CIN1) that will progress to high-grade squamous intraepithelial lesion from the majority of cases, which will resolve without further intervention. We conducted a retrospective study of CK7 IHC on adjudicated CIN1 tissue from women in the placebo arm of the quadrivalent human papillomavirus (HPV) vaccine trials. Tissue sections were stained with CK7 IHC and scored as negative, patchy, gradation (ie, top-down), or full-thickness pattern. Results were assessed for the prediction of future diagnosis of CIN2-3/AIS (eg, CIN2+ progression) along with p16 IHC, antecedent high-grade cytology, and HPV16 status. A total of 517 patients with CIN1 biopsies and complete data were identified, 12% of whom showed CIN2+ progression on follow-up. Full-thickness CK7 staining showed the highest correlation with CIN2+ progression (odds ratio [OR] 2.8, P=0.021) relative to the other risk factors (HPV16: OR 2.0, P=0.035; antecedent high-grade cytology: OR 2.2, P=0.028; p16 IHC: OR 1.5, P=0.16). Inclusion of the gradation/"top-down" CK7 pattern resulted in a less robust association with progression (CIN2+: OR 2.0, P=0.028; CIN3+: OR 1.3, P=0.74). Interobserver variability ranged from slight to substantial and was not contingent on gynecologic pathology training experience (κ=0.7078 for negative/patchy vs. gradation/full thickness; κ=0.5672 for negative/patchy/gradation vs. full thickness). These data support the theory that SCJ-derived LSILs are precursors to a potentially aggressive subset of cervical SILs and that CK7 staining may inform risk stratification for LSIL (CIN1). However, clinical utility is significantly tempered by the relatively low amplitude of the risk increase, interpretative variability, and limitations of colposcopic sampling.

Colposcopic, Histologic and Immunohistochemical Assessment in Cervical Intraepithelial Lesions

“…Also, the expression of scuamo-columnar junction with the Cytokeratin 7 (CK7) marker is associated with an increased rate of subsequent high-grade squamous intraepithelial lesion, suggesting that CK7 may inform risk stratification for CIN1 ( fig. 10) [31].…”

“…DNA HPV genotyping was performed by amplification of the target DNA by polymerase chain reaction (PCR) technique and hybridization of nucleic acids for individual Table 1 COLPOSCOPIC ASSESSMENT qualitative detection of 37 HPV anogenital types, in cervical cells collected in liquid media (6,11,16,18,26,31,33,35,39,40,42,45,51,52,53,54,55,56,58,59,61,62,64,66,67,68,69,70,71,72, 73/MM9, 81, 82/MM4, 83/MM7, 84/ MM8, IS39 and CP6108).…”

Deciphering the Multifactorial Susceptibility of Mucosal Junction Cells to HPV Infection and Related Carcinogenesis

“…In addition to being actively involved in adult adaptive processes (metaplasia, hyperplasia) [10], SC junction cells exhibit intriguing phenotypic similarities with approximately 90% of cervical SCC and high-grade precursors [9,12]. These findings underlying the instrumental role of junctional cells in cervical carcinogenesis were recently confirmed by several immunohistochemical and/or transcriptional studies analyzing the expression of SC junction-overexpressed biomarkers (i.e., cytokeratin 7 (Krt7), anterior gradient protein 2 (AGR2) or cystic fibrosis transmembrane conductance regulator (CFTR)) in large cohorts of cervical (pre)neoplastic lesions [13,14,15,16,17]. Moreover, the evidence that normal-appearing SC junction cells harbor both HPV transcripts (E6*I/II) and early viral proteins (HPV E2) was reported and sustains the possibility that these cuboidal cells could serve as a reservoir for latent infections and subsequent CIN development in asymptomatic HPV-positive patients [18].…”

“…Recently, four studies analyzed the predictive value of junctional biomarkers (especially Krt7) and, interestingly, all showed that low-grade CIN arising from the SC junction have a significantly higher risk to progress to CIN2/3 compared to their counterparts observed in the transformation zone/ectocervix [12,13,14,15]. Furthermore, when compared to other risk factors, such as HPV16 infection and diffuse p16 ink4 expression, full-thickness Krt7 immunoreactivity demonstrated the highest correlation with lesion progression [14]. Although these conclusions were shown to be reproducible and in agreement with the high percentage (~90%) of CIN3 and cervical cancers displaying immunophenotypic similarities with SC junction cells, unfortunately, Krt7 or another SC junction-specific/overexpressed protein is unlikely to be sufficiently specific to provide actionable information in the clinical setting.…”

Experimental Approaches to Deriving Primary Tumor Cell Cultures From Cervical Cancer Biopsies: A Comparative Analysis of Published Data and Own Experience

“…(Bononi, 2012), ЦK14, -17 и -19 детектируются в 100% колоний первичных клеток ЦИН, но возможно варьирование по интенсивности окрашивания (аналогичные данные описаны Liu и соавт.). В нашем случае были использованы пан-специфические меченые антитела к ЦК -7, -8, -18 и ЦК-19, из которых только ЦК-19 перекрывается со спектром ЦК, анализируемых в перечисленных публикациях, однако, для ЦК -7, -8 и -18 также есть опубликованные данные, подтверждающие, что их экспрессия характерна для ЦИН/РШМ и стандартных линий РШМ (Ikeda K, 2008;Sullivan, 2010;Lee H, 2017;Mills, 2017). Для анализа экспрессии цитокератинов в полученной культуре клеток РШМ IB стадии методом цитометрии была выбрана чашка с численным преобладанием клеток эпителиальной морфологии при достижении 70-80% конфлуентности на 0-ом пассаже.…”