Relationship between the presence of oncogenic HPV DNA assessed by polymerase chain reaction and Ki‐67 immunoquantitative features in cervical intraepithelial neoplasia

Abstract

The aims of this study were firstly to determine which Ki-67 immunoquantitative parameters correlate with the presence of oncogenic human papillomavirus (HPV) in cervical intraepithelial neoplasia (CIN) lesions; and secondly to compare prospectively the routinely assessed CIN grades with the Ki-67 quantitative pathological CIN grade, the expert revised grade, and the presence of oncogenic HPV DNA. HPV polymerase chain reaction (PCR) and Ki-67 immunoquantitation were performed on 90 consecutive biopsies (16 CIN 1, 35 CIN 2, and 39 CIN 3). CIN grade was assessed routinely by six different pathologists. The presence of the lesion was confirmed in a histological section following the material used for PCR and Ki-67 analysis. In a second prospective routine test set analysis, 66 more CIN lesions (14 CIN 1, 15 CIN 2, and 37 CIN 3) were routinely graded (also by six different pathologists, routine CIN grade=CIN(ROUT)), studied for oncogenic HPV DNA, and graded by quantitative Ki-67 features (quantitative pathological CIN grade=CIN(QP)). These latter cases were blindly revised by one of the authors (reference CIN grade=CIN(REF)). Eight of the nine Ki-67 immunoquantitative features showed a significant difference between the oncogenic HPV-positive and -negative cases. The best single discriminator was the 90th percentile of the stratification index (SI90). All 61 cases with Ki-67 SI90>0.60 were HPV-positive (68% of the total group studied). Of the 29 cases with SI90< or =0.60, 16 were negative and 13 positive for oncogenic HPV and none of the Ki-67 features (either single or combined) could distinguish them. Using stepwise multivariate analysis, the best discriminating combination of features was SI90 and the percentage of Ki-67-positive nuclei in the deep third layer of the epithelium (PERC DL). The combination of SI90 and the percentage of Ki-67-positive nuclei per 100 microm basal membrane was nearly as strong as that of SI90 and PERC DL. With these two features, 86% of the cases were correctly classified. The subjective estimate of SI90 (>0.60 or < or =0.60) by two independent observers was not accurate and not reproducible. In the prospective routine test set analysis of 66 cases, the 37 CIN(ROUT)=3 all had CIN(QP) and CIN(REF)=3 and all these cases were oncogenic HPV-positive. Eight of the 14 original CIN(ROUT)=1 grades were oncogenic HPV (=HPV)-positive and five of these eight were upgraded by CIN(QP) to CIN 2 and CIN 3. These upgrades were in agreement with the blind reference revisions. The six HPV-negative CIN(ROUT)=1 cases were CIN 1 both by CIN(QP) and by CIN(REF). Thirteen of the 15 original CIN(ROUT)=2 grades were HPV-positive and seven of these were CIN(QP)=3. All six HPV-positive CIN(ROUT)=2 cases that were CIN(QP)=2 were also CIN(REF)=2 at blind revision. In conclusion, this study has shown firstly, that in CIN lesions, Ki-67 immunoquantitative features and the presence of oncogenic HPV are highly correlated, and also within one subjective CIN grade; secondly, that subjective impressions of SI90 are not a...

Prognostic Value and Reproducibility of Koilocytosis in Cervical Intraepithelial Neoplasia

“…Interobserver differences in the classification of CIN grades are substantial even among well-trained observers, especially for less severe grades (13). Ki-67 quantitative image analysis has good reproducibility and could be used as a diagnostic support method for grading, especially in a research setting (11,12,14). We cannot exclude grading variability in the biopsy interpretation in this study, but this probably was not a significant factor because progression rates in the current study were similar to those in many international studies (2).…”

“…Earlier studies have shown that Ki-67 immunoquantitation is a sensitive marker of grade, presence or absence of oncogenic HPV, and possibly, biological behavior (11,12). We also found that quantitative image analysis obtains the most reliable and best predictive results of these CIN characteristics.…”

“…We also found that quantitative image analysis obtains the most reliable and best predictive results of these CIN characteristics. Subjective Ki-67 analyses, even by experienced surgical pathologists aware of the prognostic thresholds and significance of the quantitative Ki-67 features, have proven to be insufficiently accurate to detect the subtle changes caused by HPV within each CIN grade, whereas the quantitative analysis revealed such differences (12). Quantitative Ki-67 analysis also is important for another reason.…”

Dynamic behavioural interpretation of cervical intraepithelial neoplasia with molecular biomarkers

“…19 20 88 Figure 6 shows the quantitative image analysis method. The combination of the Stratification Index (SI, which indicates, how high Ki-67positive nuclei are located in the epithelium; the higher the SI, the higher the CIN grade) and the number of Ki-67positive nuclei per 100 mm basal membrane (the more Ki-67positive nuclei, the higher the grade) is the best discriminating set of features that distinguishes the three CIN grades at the same time (fig 7).…”

“…[12][13][14][15][16][17][18][19][20] Without doubt, p16 and Ki-67 are the most widely available, robust, stable and strong predictive biomarkers currently available for handling CIN lesions. (The antibody MIB-1 is often used in paraffin wax sections to assess Ki-67 expression.…”