The role of deeper levels and ancillary studies (p16^Ink4a and ProExC) in reducing the discordance rate of Papanicolaou findings of high‐grade squamous intraepithelial lesion and follow‐up cervical biopsies

Abstract

BACKGROUND: Discordant results of cervical biopsy histology after a cytologic diagnosis of high‐grade squamous intraepithelial lesion (HSIL) are often attributed to sampling variation. The purpose of the current study was to determine whether deeper levels and ancillary staining (p16Ink4a and ProExC) reduce the discordant rate. METHODS: A total of 246 cases of HSIL were retrieved from the computerized database from 2005 and 2006. Of these cases, 151 were followed by cervical biopsy. There was cytologic‐histologic correlation in 87 cases, as defined by the presence of high‐grade (2 or 3) cervical intraepithelial neoplasia (HGCIN). For each discordant biopsy (n = 64), 2 deeper levels for hematoxylin and eosin (H&E) were taken at 30‐μ and 90‐μ depths, and 4 sections for p16Ink4a and ProExC staining were taken at a 60‐μ depth. All cytologic and histologic material from these 64 cases was reviewed by 3 cytopathologists. In 2 cases, the original HSIL diagnoses were downgraded and the cases censored from the study. RESULTS: Fifty‐seven of the 62 discordant cases had sufficient tissue for deeper levels and ancillary staining. Two of 57 cases were reclassified to HGCIN. In both of these cases, reclassification was suggested by results of immunostains; however, the H&E sections were necessary for definitive interpretation of the immunostain results. CONCLUSIONS: In the current study, deeper levels and ancillary staining with p16Ink4a and ProExC did not significantly reduce the discordance rate. Although there are many known causes of sampling variation, including factors related to colposcopic technique, regression of infection, and insufficient histologic sectioning, sampling variation remains a valid justification of noncorrelation in women with HSIL followed up by cervical biopsy alone. Cancer (Cancer Cytopathol) 2009. © 2009 American Cancer Society.

A cocktail of MCM2 and TOP2A, p16 INK4a and Ki-67 as biomarkers for the improved diagnosis of cervical intraepithelial lesion

“…It is necessary to distinguish normal from CIN of any grade, and benign or lower-grade CIN, which is mostly transient dysplasia (CIN 1), from high-grade CIN. P16 is a preferable substitute indicator for Hr-HPV infection, and its expression in CIN is widely researched and reported [1][2][3][4][5][6][7][8][9][10][12][13][14][15][16][17][18]. According to previous studies [3], p16 showing diffuse strong positivity was highly sensitive to CIN 3 and CIN 2 but insensitive to CIN 1.…”

“…The following situations were interpreted to be negative: positive cells were less than 5%; the antibody cocktail and Ki-67 staining was distributed on basal 1-2 layers of cells; p16 was stained only on cytoplasm. According to David's method [12], negative results of the antibody cocktail, p16 and Ki-67 were considered as without CIN; the antibody cocktail (2+), p16 (1+ & 2+) and Ki-67 (2+) were all CIN 1; the antibody cocktail, p16, and Ki-67 (≥ 3+) were CIN 2-3, in which immunostaining scoring 4+ was judged as CIN 3.…”

“…P16 INK4a (p16) is a kind of anti-oncogene and considered as a preferable substitute marker for Hr-HPV infection [1][2][3][4][5][6][7][8][9][10][12][13][14][15][16][17][18]. As a cyclin-dependent kinase inhibitor, p16 competes with cyclin D1 to combine with CDK4/6 and specifically suppresses the activity of CDK4, inhibiting the CDK-induced phosphorylation of pRb and arresting the cell transition from G1 phase to S phase, thereby playing a role in feedback control of mitosis.…”

“…Recently, a biomarker cocktail containing antibodies against minichromosome maintenance protein 2 (MCM2) and topoisomerase IIα (TOP2A) has been reported as a potential diagnostic adjunct for CIN [4,12,13,20]. During DNA replication, MCM2 functions by loading the complex onto DNA before replication and unwinding the DNA through helicase activity to permit DNA synthesis.…”

Variability of Pathologists' Utilization of p16 and Ki-67 Immunostaining in the Diagnosis of Cervical Biopsies in Routine Pathology Practice and Its Impact on the Frequencies of Cervical Intraepithelial Neoplasia Diagnoses and Cytohistologic Correlations

“…However, a recent study that examined the value of deeper levels and ancillary staining with p16 and ProExC (BD) found a modest increase in CHC frequencies by identifying CIN2þ in 2 of 57 discordant biopsy specimens obtained for a prior cytologic diagnosis of HSIL. 12 A higher frequency of p16 immunostain use correlated positively with the volume of cervical biopsies examined by the pathologist, and with specialized training in cytopathology or gynecologic pathology, and correlated inversely with the experience of the pathologist in terms of years of practice of surgical pathology. The use of p16 did not correlate with the type of pathology practice (academic versus community) or with the characteristics of the patient population in terms of age and prior Pap test diagnoses.…”