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

Evaluation of HPV infection and smoking status impacts on cell proliferation in epithelial layers of cervical neoplasia

Accurate cervical intra-epithelial neoplasia (CIN) lesion grading is needed for effective patient management. We applied computer-assisted scanning and analytic approaches to immuno-stained CIN lesion sections to more accurately delineate disease states and decipher cell proliferation impacts from HPV and smoking within individual epithelial layers. A patient cohort undergoing cervical screening was identified (n = 196) and biopsies of varying disease grades and with intact basement membranes and epithelial layers were obtained (n = 261). Specimens were sectioned, stained (Mib1), and scanned using a high-resolution imaging system. We achieved semi-automated delineation of proliferation status and epithelial cell layers using Otsu segmentation, manual image review, Voronoi tessellation, and immuno-staining. Data were interrogated against known status for HPV infection, smoking, and disease grade. We observed increased cell proliferation and decreased epithelial thickness with increased disease grade (when analyzing the epithelium at full thickness). Analysis within individual cell layers showed a ≥50% increase in cell proliferation for CIN2 vs. CIN1 lesions in higher epithelial layers (with minimal differences seen in basal/parabasal layers). Higher rates of proliferation for HPV-positive vs. -negative cases were seen in epithelial layers beyond the basal/parabasal layers in normal and CIN1 tissues. Comparing smokers vs. non-smokers, we observed increased cell proliferation in parabasal (low and high grade lesions) and basal layers (high grade only). In sum, we report CIN grade-specific differences in cell proliferation within individual epithelial layers. We also show HPV and smoking impacts on cell layer-specific proliferation. Our findings yield insight into CIN progression biology and demonstrate that rigorous, semi-automated imaging of histopathological specimens may be applied to improve disease grading accuracy.

Molecular targets of HPV oncoproteins: potential biomarkers for cervical carcinogenesis

Cervical cancer is the second most common cancer among women worldwide and is responsible for 275,000 deaths each year. Persistent infection with high-risk human papillomavirus (HR-HPV) is an essential factor for the development of cervical cancer. Although the process is not fully understood, molecular mechanisms caused by HPV infection are necessary for its development and reveal a large number of potential biomarkers for diagnosis and prognosis. These molecules are host genes and/or proteins, and cellular microRNAs involved in cell cycle regulation that result from disturbed expression of HR-HPV E5, E6 and E7 oncoproteins. One of the current challenges in medicine is to discover potent biomarkers that can correctly diagnose cervical premalignant lesions and standardize clinical management. Currently, studies are showing that some of these molecules are potential biomarkers of cervical carcinogenesis, and it is possible to carry out a more accurate diagnosis and provide more appropriate follow-up treatment for women with cervical dysplasia. In this paper, we review recent research studies on cell cycle molecules deregulated by HPV infections, as well as their potential use for cervical cancer screening.

Dynamin 2 expression as a biomarker in grading of cervical intraepithelial neoplasia

OBJECTIVE

Dynamin 2, which plays a role in endocytosis, is known to be required for HPV infection on host cells. We investigated dynamin 2 as a biomarker in grading of cervical intraepithelial neoplasia (CIN) by comparing with Ki-67 expression and the type of HPV infection (low-risk vs. high-risk).

STUDY DESIGN

We performed immunohistochemical stains of dynamin 2 and Ki-67 on tumor samples of patients with CIN and the type of HPV infection was investigated.

RESULTS

All the patients with reactive changes (n=7) or normal (n=4) did not show dynamin 2 expression. There were 33, 14, and 12 cases with CIN I, II, and III, respectively, and there was a negative correlation between the degree of dynamin 2 expression and the severity of CIN lesions with statistical significance (P<0.001). Negative expression of dynamin 2 was more sensitive for the detection of CIN II/III than high expression (2+) of Ki-67 (96.2% vs. 73.1%, P=0.041). Among patients in whom HPV infection was detected, the degrees of dynamin 2 expression were not associated with the type of HPV infection (low-risk vs. high-risk). Overall, there was a negative correlation between the expression patterns of Ki-67 and dynamin 2.

CONCLUSION

We found that dynamin 2 may be a helpful biomarker in grading of CIN lesions and a candidate biomarker for detecting low grade CIN with high sensitivity.

Biomarkers of cervical dysplasia and carcinoma

Although cervical cytology screening has decreased the incidence of cervical cancer in industrialized countries, HPV-related cervical disease, including premalignant and malignant lesions, continues to represent a major burden on the health care system. Some of the problems include the potential for either under- or overtreatment of women due to decreased specificity of screening tests as well as significant interobserver variability in the diagnosis of cervical dysplastic lesions. Although not completely elucidated, the HPV-driven molecular mechanisms underlying the development of cervical lesions have provided a number of potential biomarkers for both diagnostic and prognostic use in the clinical management of these women.

Functional biomarkers in cervical precancer: an overview

Cervical cancer develops over a long time through precursor lesions that can be detected by cytological screening. Majority of these lesions regress spontaneously. Therefore, the challenge of cervical cancer screening is to detect the lesions that have a high risk of progression. Several promising biomarkers have been described that may improve screening of cervical cancer, but to date, new biomarkers have not been thoroughly validated in high-quality studies. The knowledge about human papillomavirus as a causative agent of cervical cancer has accumulated over the last decades has opened the possibility to improve the existing prevention strategies and screening practices. p16 has amply been applied on cytologic samples and has been shown to be a promising marker especially in identification of high-grade dysplasia. ProEx C, a replication marker, has also been recently shown to be a good marker for identification of high-grade dysplasia and has been used on cytologic samples. Proliferation markers such as MYC, Ki67, telomerase, MCM, topoisomerase 2A and 3q amplification by in situ hybridization technique are other methods being employed in identification of high-grade dysplasia. However, currently available data on most of the biomarkers does not warrant their routine use yet. This review highlights the major findings of previous studies on cervical cancer biomarkers.

Ki-67 quantitative evaluation as a marker of cervical intraepithelial neoplasia and human papillomavirus infection

OBJECTIVE

To assess the value of Ki-67 quantitative analysis in cervical intraepithelial neoplasia (CIN) in relation to CIN grading and human papillomavirus (HPV) group typing.

METHODS

Cervical samples selected retrospectively from 106 cases were analyzed immunohistochemically for Ki-67-positive nuclei in 3 epithelial layers and by polymerase chain reaction for HPV typing.

RESULTS

The proportion of high-risk HPV positivity was 0% in normal controls and 30% in CIN 1, 57% in CIN 2, and 90% in CIN 3 groups, and there was no low-risk HPV finding in CIN 2 and CIN 3 cases (P < 0.001). High-risk HPV-positive cases exhibited significantly more Ki-67-positive nuclei per 100-mum basal membrane, which were more frequent in the middle and upper third layers of the epithelium compared with low-risk HPV and HPV-negative cases (P < 0.001). The differences among the CIN groups in the total number and in the percentages of Ki-67-positive nuclei in the lower, middle, and upper third layers of the epithelium were significant (P < 0.001). With the cutoff value of more than 33% Ki-67-positive nuclei in the middle and the upper third layers of the epithelium, Ki-67 staining demonstrated 98.4% sensitivity (60/61 cases) and 97.8% specificity (44/45 cases) for the detection of CIN 2/CIN 3 in our study group.

CONCLUSIONS

The Ki-67 immunostaining proved to be predictive for high-risk HPV infection, and it can differentiate reactive lesions from cervical dysplasias. Ki-67 quantitative analysis in 3 epithelial layers is a sensitive and specific method of differentiation between CIN 1 and CIN 2/CIN 3 grades and can be a valuable adjunctive method for more accurate CIN grading.

Quantitative detection of molecular markers ProEx C (minichromosome maintenance protein 2 and topoisomerase IIa) and MIB-1 in liquid-based cervical squamous cell cytology

BACKGROUND

In this study, the authors conducted a comparative quantitative evaluation of the proliferation markers ProEx C (an aberrant S-phase induction marker, human papillomavirus E6-E7 correlated) and MIB-1 in squamous intraepithelial lesions (SIL) to identify a biomolecular profile informative for the diagnosis of high-grade SIL/cervical intraepithelial neoplasia 3 or greater that was complementary to the morphologic Papanicolaou (Pap) test ("biomolecular Pap test").

METHODS

After the cytologic diagnosis, reflex immunocytochemistry was carried out on 76 unstained SurePath cell samples (20 routine samples that were negative for intraepithelial lesion or malignancy and 56 positive samples that were selected with matching histology). Both a morphometric analysis with a software imaging analysis system and a quantitative analysis of atypical squamous clusters were performed.

RESULTS

The quantitative evaluation revealed an excellent, direct correlation between the 2 markers, although ProEx C was more selective and more informative for the progression of low- and moderate-grade lesions, because it only revealed cells in aberrant S-phase cell cycle. The quantitative morphometric analysis revealed the increased presence of atypical, positive clusters and the percentage of positive cells within, both paralleling the severity of the lesions. The threshold of a 3% ProEx C-positive nuclear area was useful for splitting lesions into groups with a low risk or high risk of progression.

CONCLUSIONS

Both ProEx C and MIB-1 were valid proliferation markers in cytologic preparations, and nuclear positivity was quantified successfully by using computer-assisted analysis. The analysis of atypical clusters may be a valuable tool in the diagnosis of SIL. The presence of atypical clusters and their positivity for proliferation markers are good first-glance indicators of lesion grade.

The expression of p16 (INK4a) and Ki-67 in relation to high-risk human papilloma viral load and residual disease after conization with positive margins

The purpose of this study was to investigate the correlations between high-risk human papillomavirus (HPV) load and p16 (INK4a) or Ki-67, and to identify biomarkers that may predict residual disease after conization with positive margins. The following samples were analyzed: 49 paraffin-embedded specimens from patients with cervical intraepithelial neoplasia (CIN), including 12 CIN 2 conization specimens and 37 CIN 3 conization specimens. Immunohistochemical analysis was performed with antibodies to p16 (INK4a) and Ki-67. Hybrid Capture II testing was used to detect high-risk HPV DNA. The mean HPV loads within each of the p16 (INK4a)-staining cases were 9.5 (relative light units/positive control) RLU/PC for negative staining, 531.8 RLU/PC for 1+ staining, 140.2 RLU/PC for 2+ staining, and 545.1 RLU/PC for 3+ staining. HPV loads differed significantly according to p16 (INK4a) expression (P = 0.0021). The mean HPV loads within Ki-67 staining cases were 28.2 RLU/PC for 1+ staining, 189.6 RLU/PC for 2+ staining, and 563.3 RLU/PC for 3+ staining. HPV loads differed significantly according to Ki-67 expression (P = 0.0259). The expression of p16 (INK4a) (P = 0.0012) and Ki-67 (P = 0.0006) were significantly associated with the CIN grade. In univariate and multiple logistic regression analysis, age, parity, cytology, lesion grade in the cone, high-risk HPV load, and the expression of p16 (INK4a) and Ki-67 were not significantly associated with residual lesions after conization with positive margins (P > 0.05). In conclusion, high-risk HPV load showed significant differences according to the expression of p16 (INK4a) and Ki-67, while none of the prognostic factors were significantly associated with residual disease after conization with positive margins.

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.

Distribution of HPV infection and tumour markers in cervical intraepithelial neoplasia from cone biopsies of Mozambican women

AIMS

To evaluate human papillomavirus (HPV) infection in whole cervical cone specimens with cervical intraepithelial neoplasia (CIN). In addition, to evaluate the relation between the presence of CIN lesions and HPV infection and the expression of Ki-67, p53, cytokeratins, Gp230 glycoprotein, and simple mucin-type carbohydrates.

METHODS

Cervical cone specimens from five patients with CIN were studied. For each specimen, serial sections encompassing the whole cone were collected (52 samples). HPV infection and HPV types were detected by the polymerase chain reaction and enzyme immunoassay. The expression of Ki-67, p53, cytokeratins, Gp230, and simple mucin-type carbohydrates was examined immunohistochemically.

RESULTS

All cases showed high risk HPV types, namely types 16, 33, 35, and 58. Four of the five patients were infected by multiple viral types. HPV-58 was always seen in CIN III, whereas HPV-35 was more frequent in CIN I. The expression of Ki-67 and p53 was higher in CIN III lesions. The expression of cytokeratins 8 and 17 showed complete or almost complete overlap with CIN III. Altered expression of Gp230, Tn, and sialyl-T was often seen in all grades of CIN.

CONCLUSIONS

When whole cervical cone specimens are evaluated the rate of multiple HPV infection is very high. The expression of cytokeratins 8 and 17 is a useful marker of CIN III.

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.

Essential oils and low-intensity electromagnetic pulses in the treatment of androgen-dependent alopecia

This double-blind randomized study vs placebo in healthy male and female volunteers demonstrates the positive biologic effect on hair loss and hair regrowth of a pulsed electromagnetic field in combination with essential oils administered according to a regular treatment schedule of 26 weeks. Mean hair count comparisons within the groups significantly favor the treatment group, which exhibited a decrease in hair loss in 83% of the volunteers and a more than 20% hair count increase over baseline in 53% of patients. The process exhibited no side effects or untoward reactions. The histologic examination correlated with the clinical study. A parallel immunohistochemical examination showed an increase in the proliferation index, and when the expression of Ki67 (a cell proliferation marker) is increased, the mitoses are barely visible in the histologic examination. The rationale of this phenomenon is considered to be due to an electrophysiologic effect on the quiescent hair follicle.

Prognostic value and reproducibility of koilocytosis in cervical intraepithelial neoplasia

The purpose of this study was to evaluate the influence of koilocytosis on the progression of cervical intraepithelial neoplasia (CIN) to a higher grade during follow-up in cervical biopsy specimens with CIN 1 and 2. In adequate, consecutive, biopsy specimens of 103 CIN 1 and 2 patients, CIN grade and presence or absence of koilocytosis were assessed. Patients were followed by colposcopy and cytology according to protocol. When recurrent CIN was suspected with either of the techniques, a re-biopsy was taken. Progression of the CIN was defined as an increase of grade by at least 1. Univariate analysis was applied to all patients and in the CIN 1 and 2 subgroups separately. An experienced gynecological pathologist using strict criteria reviewed koilocytosis. The Kappa test was used to assess interobserver reproducibility of koilocytosis. Koilocytosis was found in 70 (68%) of the specimens (18 of 29=62% of the CIN 1 and 52 of 74=70% of the CIN 2 cases). Twenty-one of 103 (20%) dysplasias progressed and 10 of these (48%) showed koilocytosis. Koilocytosis was found more frequently (73%, 60 of 82) in the cases that showed no progression. Follow-up showed that patients with koilocytosis had a significantly lower likelihood of progression (log-rank=5.5, p=0.02). In CIN 1, progression without and with koilocytosis was 27% and 0%, respectively, log-rank=4.9, p=0.03. In CIN 2, a similar trend was found: only 10 of 52 (19%) CIN 2 cases with koilocytosis progressed, whereas 8 of 22 (36%) lesions lacking koilocytosis progressed, a difference just below significance (p=0.06). In agreement with other studies, interobserver diagnosis of koilocytosis was poorly reproducible. In conclusion, the presence of koilocytosis is associated with a lack of progression in CIN 1 lesions, but reproducibility of koilocytosis assessment is not optimal. Therefore, other more objective and better reproducible criteria are required to extract the potentially important prognostic information contained in the microscopic image of CIN 1 and 2 lesions.

Low- and high-risk CIN 1 and 2 lesions: prospective predictive value of grade, HPV, and Ki-67 immuno-quantitative variables

The aim of this study was to evaluate in small cervical biopsies (non-cone, non-large loop excision of the transformation zone, LLETZ) the prognostic value of both routinely assessed and reviewed cervical intraepithelial neoplasia (CIN) grades 1 and 2, oncogenic human papillomavirus (onco-HPV) DNA (HPV status) and Ki-67 immuno-quantitative features for the prediction of progression. In biopsies from 44 CIN patients (the learning set), subjective CIN grade, onco-HPV by PCR, and Ki-67 immuno-quantitative features were assessed. We followed development of the lesions by colposcopy and cytology, but the final endpoint was the histological grade (again in small biopsies). The outcome was defined as progression (histological (CIN 1 to (CIN 2 or 3)) or CIN 2 to CIN 3) or not (all other cases). Single and multivariate (Cox regression) and survival analyses were applied. The resulting predictive combination of quantitative features was then applied to a new test set of 35 consecutive CIN 2 (small) biopsies followed by large (cone or LLETZ) biopsies. In the learning set, mean follow-up of non-progression cases was 18.8 months (range 4.7-35.9), and of progression cases 13.1 months (range 6.4-32.9) (p = 0.18). Five cases progressed (11%). Of the 16 CIN 1 and 28 CIN 2 lesions, 31 cases (70%) were onco-HPV positive (5 of the CIN 1 and 26 of the CIN 2). The age of women with progression or not did not differ (p = 0.68). All 5 progression cases were CIN 2 (on review, one of these was reclassified as CIN 1), and positive for onco-HPV. Cox regression analysis showed that the percentage of Ki-67-positive cells located in the middle third layer of the epithelium (MIDTHIRD) and the 90th percentile of the stratification index (SI90) was the best combination to predict progression (log rank = 5.1, p = 0.02). Furthermore, sensitivity (100%), specificity (56%), positive predictive value (23%), negative predictive value (100%), and overall percentage correctly classified cases (61%) of this Ki-67 combination were higher than that of subjective CIN grade or HPV status, either single or combined (both for routine and review CIN grades). Adding CIN grade or HPV status did not improve the Ki-67 prognostic results. Application of the prognostic Ki-67 combination to the test set of 35 small biopsies followed by large (cone or LLETZ biopsies) gave comparable results. Analyses on homogeneous subgroups (CIN 2 only, onco-HPV+ only, or CIN2/onco-HPV+ only) gave similar results. In conclusion, Ki-67 immuno-quantitation of small biopsies showing CIN 1 or CIN 2 has strong independent prognostic value for progression.

Translational approaches to improving cervical screening

Screening programmes for cervical cancer using the current test--the Pap smear--have markedly reduced the incidence of the disease. However, an individual Pap test is of limited sensitivity and is difficult and expensive to perform. Increased understanding of the molecular pathogenesis of cervical cancer indicates that new approaches to screening might offer increased accuracy, affordability and the potential for automation. Such approaches exemplify how improved understanding of the biology of neoplasia might be translated into clinical benefit.

Evaluation of MIB-1-positive cell clusters as a diagnostic marker for cervical intraepithelial neoplasia

The objects of the study were to evaluate MIB-1-positive cell clusters (MIB-C) for distinguishing normal, reactive, and cervical intraepithelial neoplasia (CIN) biopsies and to determine possible pitfalls. Seventy-seven consecutive cervical specimens routinely diagnosed (Dx_orig) as CIN 1 or 2, or no-CIN, were revised independently by two expert gynecopathologists. MIB-1 staining and oncogenic human papillomavirus (HPV) assessment (by polymerase chain reaction) were performed. Independent diagnoses (plus oncogenic HPV status, in case of disagreement between the experts) were used to obtain a final diagnosis (Dx_final) and compared with MIB-C. Four of the 27 (15%) Dx_final = normal were HPV positive. Agreement between the gynecopathologists was 72 of 77 (94%). There were 30 (39%) discrepancies between Dx_orig and Dx_final (23 = 30% downgrades and 7 = 9% upgrades). All 23 downgrades were HPV negative and all seven upgrades were HPV positive. Overall agreement between Dx_orig and MIB-C was 73%, and with Dx_final 99%. Sensitivity, specificity, and positive and negative predictive values of MIB-C were very high without false negatives. Tangential cutting of MIB-1-positive parabasal cells and inflammatory cells can erroneously be overdiagnosed as a MIB-C. One single false positive of the 48 non-CIN cases (an immature squamous metaplasia) showed a special, easily recognizable MIB-1 pattern, different from CIN because the MIB-1 staining in the nuclei is not diffuse (as in CIN) but clumped. Moreover, positive nuclei are somewhat less densely packed than in CIN. When tangentially cut parabasal cells and inflammatory cells are carefully excluded, MIB-C is a strong diagnostic adjunct in distinguishing CIN from normal or benign cervical squamoepithelial lesions.