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

The aims of this study were firstly to determine which Ki-67 immunoquantita tive parameters correlate with the presence of oncogenic human papillomavir us (HPV) in cervical intraepithelial neoplasia (CIN) lesions; and secondly to compare prospectively the routinely assessed CIN grades with the Ki-67 q uantitative pathological CIN grade, the expert revised grade, and the prese nce of oncogenic HPV DNA. HPV polymerase chain reaction (PCR) and Ki-67 imm unoquantitation were performed on 90 consecutive biopsies (16 CIN 1, 35 CIN 2, and 39 CIN 3). CIN grade was assessed routinely by six different pathol ogists. The presence of the lesion was confirmed in a histological section following the material used for PCR and Ki-67 analysis. In a second prospec tive routine test set analysis, 66 more CIN lesions (14 CIN 1, 15 CIN 2, an d 37 CIN 3) were routinely graded (also by six different pathologists, rout ine CIN grade = CINROUT), studied for oncogenic HPV DNA, and graded by quan titative Ki-67 features (quantitative pathological CIN grade = CINQP). Thes e latter cases were blindly revised by one of the authors (reference CIN gr ade = CINREF). Eight of the nine Ki-67 immunoquantitative features showed a significant difference between the oncogenic HPV-positive and -negative ca ses. The best single discriminator was the 90th percentile of the stratific ation index (S190). All 61 cases with Ki-67 S190 > 0.60 were HPV-positive ( 68%, of the total group studied). Of the 29 cases with S190: 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 multivari ate analysis, the best discriminating combination of features was S190 and the percentage of Ki-67-positive nuclei in the deep third layer of the epit helium (PERC DL). The combination of S190 and the percentage of Ki-67-posit ive nuclei per 100 mum basal membrane was nearly as strong as that of S190 and PERC DL. With these two features, 86% of the cases were correctly class ified. The subjective estimate of S190 ( > 0.60 or less than or equal to 0. 60) by two independent observers was not accurate and not reproducible. In the prospective routine test set analysis of 66 cases, the 37 CINROUT = 3 a ll had CINQP and CINREF = 3 and all these cases were oncogenic HPV-positive . Eight of the 14 original CINROUT = I grades were oncogenic HPV (= HPV)-po sitive and five of these eight were upgraded by CINQP to CIN 2 and CIN 3. T hese upgrades were in agreement with the blind reference revisions. The six HPV-negative CINROUT = 1 cases were CIN I both by CINQP and by CINREF. Thi rteen of the 15 original CINROUT = 2 grades were HPV-positive and seven of these were CINQP = 3. All six HPV-positive CINROUT = 2 cases that were CINQ P = 2 were also CINREF = 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 su bjective CIN grade; secondly, that subjective impressions of S190 are not a s accurate or reproducible as quantitative image analysis results; and thir dly, that the routine application of QP CIN-grading gives results that are in very good agreement with CIN grades assessed by an expert. Thus, routine QP-grading may be used to correct the subjective grade assessed by non-exp ert pathologists. Copyright (C) 2001 John Wiley & Sons, Ltd.