Dynamic behavioural interpretation of cervical intraepithelial neoplasia with molecular biomarkers

The microscopic phenotype of cervical intraepithelial neoplasia (CIN) reflects a fine balance between factors that promote or reduce CIN development. A shortcoming of the current grading system is its reliance on static morphology and microscopic haematoxylin-eosin features of the epithelium alone. In reality, CIN is a dynamic process, and the epithelium may exhibit differing results over time. Functional biomarkers p16, Ki-67, p53, retinoblastoma protein cytokeratin (CK)14 and CK13, help in the assessment of an individual CIN's lesion's potential for progression and regression. The aggregate information provided by these biomarkers exceeds the value of the classic grading system. Consequently, many more CINs that will either regress or progress can be accurately identified. These findings agree with known molecular interactions between HPV and the host. For accurate interpretation of a CIN, it is essential that these biomarkers be determined quantitatively and separately in the superficial, middle and deep layers of the epithelium. Such geography-specific epithelial evaluations of quantitative biomarkers emphasise the dynamic nature of a particular CIN lesion, thereby changing the art of static morphology grading into dynamic interpretation of the diseased tissue, with a strong prognostic effect.

Combined p53 and retinoblastoma protein detection identifies persistent and regressive cervical high-grade squamous intraepithelial lesions

Most cervical high-grade squamous intraepithelial lesions (HSILs) persist, but approximately one third regress (ie, no HSIL in follow-up biopsies). To identify factors related to histologic proven persistence or regression. Twenty-eight small histologic (marker) biopsies with adequate follow-up were analyzed for human papillomavirus (HPV) genotypes and different immunoquantitative proliferation, cell cycle regulation, and differentiation markers. All cases had a biopsy-interval between the marker and first follow-up biopsy of at least 100 days (median, 8.2 months; range, 3.4-22.5 months). Follow-up was classified as regression or persistence. All lesions were high-risk (hr) HPV and p16 positive, 63% for HPV-16 or HPV-16 mixed with other hr genotypes, while 37% had other hrHPV types. The marker biopsies of the persistent HSILs had lower p53 and retinoblastoma protein (pRb) detected in the deep half of the epithelium (P = 0.001 and 0.02, respectively) than nonpersistent HSILs. The degree of positivity of p16, Ki-67, cyclin D1, lesion extent, positivity of the resection margins, and patient age were all unrelated to persistence or regression. Lesions with HPV-16 or mixed-16 genotypes had a significantly lower percentage of pRb (P = 0.02), p53 (P = 0.02), and cyclin D (P = 0.04) positive nuclei in the deep epithelial layers. In agreement with this, type-16 positive HSILs had a lower regression percentage than those with other HPV types, but the difference was not significant. HSILs with combined negativity/low positivity for p53 and pRb protein in small histologic biopsies are highly likely to persist, contrasting those in which one of these cell cycle regulators is strongly positive (p53 > 15%; pRb > 40%).

Lack of PTEN expression in endometrial intraepithelial neoplasia is correlated with cancer progression

We tested the hypothesis that PTEN inactivation may stratify cancer progression risk among putative endometrial hyperplasias, classified prognostically by means of the morphometric D score (DS). The DS, calculated from 3 morphometric variables measured in routine hematoxylin-eosin-stained endometrial biopsy slides, is the most sensitive and specific method of endometrial cancer risk prediction currently available. Clinical outcomes of 103 women with endometrial hyperplasia on biopsy were tallied according to the DS. Seven (7/103; 7%) patients with carcinoma during follow-up were all distributed within the high-risk prognostic group (ie, DS <1 = endometrial intraepithelial neoplasia [EIN]) (7/21; 33% progression). None of the 82 cases with a DS higher than 1 progressed. All cases that progressed were PTEN null, indicating that this genotype is capable of further stratifying cancer progression risk in hyperplasias irrespective of histological categorization. However, only 16% of the PTEN-null cases progressed. When PTEN expression pattern was combined with EIN, the prognostic power was greatly increased (specificity from 63% for PTEN and 85% for EIN to 93% when combined; positive predictive value from 16% and 33% to 50%). We conclude that loss of PTEN expression is the first biomarker in EIN that increases the accuracy of the prognostic DS to predict cancer progression risk. Unless endometrial hyperplasias are stratified by histological morphometric D-Score, PTEN has a low positive predictive value.

Quantitative Molecular Parameters to Identify Low-Risk and High-Risk Early CIN Lesions: Role of Markers of Proliferative Activity and Differentiation and Rb Availability

In early cervical intraepithelial neoplasia (CIN), the Ki67 stratification index 90th percentile (Si90) is a strong predictor of progression. This study was designed to further investigate the mechanisms leading to elevated Ki67 levels in lesions that progress and to try to improve the prognostic accuracy of Ki67-Si90. We studied 90 CIN lesions in which consensus existed regarding the grade between two experienced gynecologic pathologists. All CINs were p16-positive and showed Ki67 cell clusters above the lower third of the epithelium (both features diagnostic for CIN). Ki67 parameters, cell cycle regulators (Rb, p53, Cyclin A, E and D, p16, p21, p27, and telomerase), and cellular differentiation products (involucrin, CK13, CK14) were compared in the basal zone as well as the deeper and upper halves of the epithelium. Fifteen CIN cases (17%) progressed to a higher CIN grade, including 2 of 25 CIN1 (8%) and 13 of 65 CIN2 (20%) (these proportions of progressing CINs are similar to those in a large meta-analysis). Ki67 quantitation effectively predicted CIN progression as 0 of 40 "Ki67 low-risk" and 15 of 50 (30%) "Ki67 high-risk" lesions progressed. CIN progressors showed decreased Rb, CK13, CK14, and involucrin, but increased p21 and p27 expression. Ki67-Si90 and Rb in the deeper half of the epithelium (RbDeep) were the strongest multivariate independent predictors of progression. Ki67-Si90>0.57 was unfavorable, but only if it coexisted with RbDeep <45% (progression risk = 47%). All early CINs with combined Si90>0.57+RbDeep>45% or any Ki67-Si90 value below 0.57 were nonprogressors. In the high-risk progression subgroup (Ki67-Si90>0.57+RbDeep<45%), all cases with combined CK14<50% and CK13<80% (both in the basal cell layer) (4% of all lesions) progressed. We hypothesize that onco-HPV E7 expression reduces Rb, causing increased and upward proliferation (Ki67-Si90>0.57). Increased RbDeep can reduce proliferation, including its upward spread. Combined quantitation of Ki67, Rb, CK13, and CK14 gives accurate information about the progression risk of early CIN lesions.