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

The Natural History of Cervical Intraepithelial Neoplasia Grades 1, 2, and 3: A Systematic Review and Meta-analysis

OBJECTIVE

The aim of the study was to obtain an updated overview of regression, persistence, and progression rates of conservatively managed cervical intraepithelial neoplasia grade 1 (CIN 1)/CIN 2/CIN 3.

METHODS

Data sources were MEDLINE, Embase, and Cochrane (January 1, 1973-April 14, 2020). Two reviewers extracted data and assessed risk of bias. To estimate outcome rates, we pooled proportions of the individual study results using random-effects meta-analysis, resulting in point estimates and corresponding 95% CIs. Heterogeneity was quantified by the I2 and τ2 measures.

RESULTS

Eighty-nine studies were included, 63 studies on CIN 1 (n = 6,080-8,767), 42 on CIN 2 (n = 2,909-3,830), and 7 on CIN 3 (n = 245-351). The overall regression, persistence, and progression to CIN 2 or worse and CIN 3 or worse rates for women with conservatively managed CIN 1 were 60% (95% CI = 55-65, I2 = 92%), 25% (95% CI = 20-30, I2 = 94%), 11% (95% CI = 8-13, I2 = 89%), and 2% (95% CI = 1-3, I2 = 82%), respectively. The overall regression, persistence, and progression rates for CIN 2 were 55% (95% CI = 50-60, I2 = 85%), 23% (95% CI = 19-28, I2 = 83%), and 19% (95% CI = 15-23, I2 = 88%), respectively. Finally, for CIN 3, these were 28% (95% CI = 17-41, I2 = 68%), 67% (95% CI = 36-91, I2 = 84%), and 2% (95% CI = 0-25, I2 = 95%), respectively. Cervical intraepithelial neoplasia grade 2 regression was significantly higher in women 30 years or younger and high-risk human papillomavirus-negative women (66%, 95% CI = 62-70, I2 = 76%; 94%, 95% CI = 84-99, I2 = 60%). Only 2/7,180 (0.03%) and 10/3,037 (0.3%) of the CIN 1 and CIN 2 cases progressed to cervical cancer.

CONCLUSIONS

Most CIN 1/CIN 2 will regress spontaneously in less than 24 months, with the highest rates in high-risk human papillomavirus-negative and young women, whereas progression to cancer is less than 0.5%. Conservative management should be considered, especially in fertile women and with expected high compliance. Given the heterogeneity in regression rates of high-grade histology, this should be classified as CIN 2 or CIN 3 to guide management.

Role of FAM19A4/miR124-2 methylation analysis in predicting regression or non-regression of CIN2/3 lesions: a protocol of an observational longitudinal cohort study

INTRODUCTION

The clinical course of high-grade cervical intraepithelial neoplasia (CIN2/3) is characterised by a high spontaneous regression rate. Histological assessment is unable to differentiate between CIN2/3 lesions likely to regress and those likely to persist or progress. Most CIN2/3 lesions are treated by surgical excision, leading to overtreatment of a substantial proportion. In this prospective study, we evaluate the value of DNA methylation of host cell genes, which has shown to be particularly sensitive for the detection of advanced CIN2/3 and cervical cancer, in the prediction of regression or non-regression of CIN2/3 lesions.

METHODS AND ANALYSIS

This is a multicentre observational longitudinal study with 24-month follow-up. Women referred for colposcopy with an abnormal cervical scrape, who have been diagnosed with CIN2/3 and a small cervical lesion (≤50% of cervix) will be asked to participate. Participants will be monitored by 6-monthly cytological and colposcopic examination. In case of clinical progression, participants will receive treatment and exit the study protocol. At baseline and during follow-up, self-sampled cervicovaginal brushes and cervical scrapes will be collected for high-risk human papillomavirus (HPV) testing and FAM19A4/miR124-2 methylation analysis. A colposcopy-directed biopsy will be taken from all participants at the last follow-up visit. The primary study endpoint is regression or non-regression at the end of the study based on the histological diagnosis. Regression is defined as CIN1 or less. Non-regression is defined as CIN2 or worse. The secondary study endpoint is defined as HPV clearance (double-negative HPV test at two consecutive time-points). The association between methylation status and regression probability will be evaluated by means of χ² testing.

ETHICS AND DISSEMINATION

Ethics approval was obtained in all participating clinics. Results of the main study will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NTR6069; Pre-results.

The association between p16 and Ki-67 immunohistostaining and the progression of cervical intraepithelial neoplasia grade 2

OBJECTIVE

To compare the frequency of p16- and Ki-67-positive cells on immunohistostaining among women with progression, persistence, or regression of cervical intraepithelial neoplasia grade 2 (CIN2).

METHODS

A retrospective study was conducted of women with CIN2 diagnosed by histology who were treated at a university hospital in Japan during 2004-2011. The immunostaining patterns for p16 and Ki-67 were analyzed and compared between patients with disease progression, persistence, or regression. Kaplan-Meier analysis was used to evaluate the progression rates stratified by immunostaining, and multivariate analysis of risk factors for progression was performed using the Cox proportional hazards model.

RESULTS

The analysis included 59 women with progression, 35 women with persistence, and 28 women with regression. Deep p16 expression (staining in more than half of the cervical intraepithelial compartment) and positive Ki-67 staining in more than 50% of cells were significantly more common among women with progression than among those with regression. The risk factors for progression of CIN2 were deep p16 expression (P<0.001) and a Ki-67 ratio of more than 50% (P<0.001).

CONCLUSION

Among women with CIN2, positive immunohistostaining for p16 and Ki-67 was strongly associated with disease progression.

Natural history of high-grade cervical intraepithelial neoplasia: a review of prognostic biomarkers

The natural history of high-grade cervical intraepithelial neoplasia (CIN) is largely unpredictable and current histopathological examination is unable to differentiate between lesions that will regress and those that will not. Therefore, most high-grade lesions are currently treated by surgical excision, leading to overtreatment and unnecessary complications. Prognostic biomarkers may differentiate between lesions that will regress and those that will not, making individualized treatment of high-grade CIN possible. This review identifies several promising prognostic biomarkers. These biomarkers include viral genotype and viral DNA methylation (viral factors), human leukocyte antigen-subtypes, markers of lymphoproliferative response, telomerase amplification and human papillomavirus-induced epigenetic effects (host factors) and Ki-67, p53 and pRb (cellular factors). All identified biomarkers were evaluated according to their role in the natural history of high-grade CIN and according to established criteria for evaluation of biomarkers (prospective-specimen-collection, retrospective-blinded-evaluation [PROBE] criteria). None of the biomarkers meets the PROBE criteria for clinical applicability and more research on prognostic biomarkers in high-grade CIN is necessary.

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.

Human papillomavirus, p16(INK4A), and Ki-67 in relation to clinicopathological variables and survival in primary carcinoma of the vagina

Background:

This study aimed to determine human papillomavirus (HPV) status and to investigate p16^INK4A and Ki-67 expression and their correlation with clinical parameters and survival in women with primary carcinoma of the vagina (PCV).

Methods:

The presence of HPV DNA was evaluated by PCR. Genotyping was performed by Luminex in 68 short-term (⩽2 years) and long-term (⩾8 years) PCV survivors. p16^INK4A and Ki-67 expression was evaluated by immunohistochemistry.

Results:

Human papillomavirus DNA was detected in 43% of patients, the majority (63%) of whom were HPV16 positive. High p16^INK4A expression was significantly correlated with low histopathological grade (P=0.004), HPV positivity (P=0.032), and long-term survival (P=0.045). High Ki-67 expression was negatively correlated with histopathological grade (P<0.001) and tumour size (P=0.047). There was an association between HPV positivity and low histopathological grade, but not between HPV positivity and survival.

Conclusion:

High p16^INK4A expression was associated with long-term survival, but the only independent predictors for survival were tumour size and histopathological grade. Our results indicate that p16^INK4A and Ki-67 expression might be useful in tumour grading, and that it might be possible to use p16^INK4A expression as a marker for HPV positivity, but this has to be further elucidated.

Multiple biomarkers in molecular oncology. I. Molecular diagnostics applications in cervical cancer detection

The screening for cervical carcinoma and its malignant precursors (cervical neoplasia) currently employs morphology-based detection methods (Papanicolaou [Pap] smear) in addition to the detection of high-risk human papillomavirus. The combination of the Pap smear with human papillomavirus testing has achieved significant improvements in sensitivity for the detection of cervical disease. Diagnosis of cervical neoplasia is dependent upon histology assessment of cervical biopsy specimens. Attempts to improve the specificity of cervical disease screening have focused on the investigation of molecular biomarkers for adjunctive use in combination with the Pap smear. Active research into the genomic and proteomic alterations that occur during human papillomavirus-induced neoplastic transformation have begun to characterize some of the basic mechanisms inherent to the disease process of cervical cancer development. This research continues to demonstrate the complexity of multiple genomic and proteomic alterations that accumulate during the tumorigenesis process. Despite this diversity, basic patterns of uncontrolled signal transduction, cell cycle deregulation, activation of DNA replication and altered extracellular matrix interactions are beginning to emerge as common features inherent to cervical cancer development. Some of these gene or protein expression alterations have been investigated as potential biomarkers for screening and diagnostics applications. The contribution of multiple gene alterations in the development of cervical cancer suggests that the application of multiple biomarker panels has the potential to develop clinically useful molecular diagnostics. In this review, the application of biomarkers for the improvement of sensitivity and specificity of the detection of cervical neoplasia within cytology specimens will be discussed.

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.

Understanding HPV tests and their appropriate applications

Greater understanding of the role played by human papillomavirus (HPV) in the causation of disease has led to the development of an increasing number of HPV tests with different characteristics. The bewildering choice facing healthcare professionals and providers is daunting. Clearly, HPV testing is no longer simply of research interest, but can provide information that can be used for individual patient management and at the population level for cervical screening and vaccine surveillance. This review aims to provide the background to the development of HPV tests, to explain the different technologies and to discuss the challenges of the application of these optimally in the varied contexts of disease management. Few HPV tests are approved for clinical use and it is important that clinicians understand which test can be utilized, in what circumstances, with what specimens and the meaning of the report issued. HPV testing is no longer applicable only to cervical disease, and we have suggested additional areas, such as the oropharynx, in which HPV testing services might be implemented in the near future. New tests will continue to emerge and we have identified some of the indirect measures of HPV activity, or biomarkers, that could help in the risk stratification of HPV infection and associated disease. The challenges relating to the optimal application of the various HPV technologies are compounded by the lack of evidence regarding their performance in vaccinated populations. Currently published work, including modelling studies, has been undertaken in non-immunized populations. We therefore end by addressing the issues regarding appropriate strategies and tests for immunized populations.

Role of protein biomarkers in the detection of high-grade disease in cervical cancer screening programs

Since the Pap test was introduced in the 1940s, there has been an approximately 70% reduction in the incidence of squamous cell cervical cancers in many developed countries by the application of organized and opportunistic screening programs. The efficacy of the Pap test, however, is hampered by high interobserver variability and high false-negative and false-positive rates. The use of biomarkers has demonstrated the ability to overcome these issues, leading to improved positive predictive value of cervical screening results. In addition, the introduction of HPV primary screening programs will necessitate the use of a follow-up test with high specificity to triage the high number of HPV-positive tests. This paper will focus on protein biomarkers currently available for use in cervical cancer screening, which appear to improve the detection of women at greatest risk for developing cervical cancer, including Ki-67, p16^INK4a, BD ProEx C, and Cytoactiv HPV L1.

Diagnostic implications of L1, p16, and Ki-67 proteins and HPV DNA in low-grade cervical intraepithelial neoplasia

The expressions of p16, Ki-67, and L1 proteins and human papillomavirus DNA were investigated using polymerase chain reaction (HPV/PCR) and catalyzed signal-amplified colorimetric DNA in situ hybridization (CSAC/ISH) as potential molecular markers for the diagnosis and transforming potential of low cervical intraepithelial neoplasia (CIN1). Ki-67 and p16 protein expression increased linearly from control cases to more dysplastic cases (CIN1, CIN2, and CIN3), peaking in squamous cell carcinoma cases (P<0.05). In contrast, L1 expression was inversely correlated with malignant transformation. Patients with CIN1 were divided into 4 groups: L1p16, L1p16, L1p16, and L1p16, and the immunohistochemical results were combined with HPV/PCR, L1/PCR, and high-risk E6/E7 genome and CSAC/ISH data. Malignant transformation correlated with L1p16 patients (100% of CIN2, CIN3, and squamous cell carcinoma cases) and was evident in approximately 23% of CIN1 cases. In addition, the presence of HPV/DNA was evident in 52% of CIN1 cases, and within the L1p16 group. In 4 of 7 cases, the high-risk E6/E7 HPV genome was present and in 1 case it was integrated into the host DNA, as confirmed using CSAC/ISH. In patients with CIN1, investigating the presence of HPV/DNA using PCR and the presence of the high-risk E6/E7 genome is necessary to distinguish high-risk oncogenic patient groups from low-risk groups. This study highlights the importance of combining immunohistochemical analysis with HPV/PCR and CSAC/ISH to identify patients with CIN1 with a risk of neoplastic progression.

Diagnostic role of p16/INK4A protein in Human Papillomavirus (HPV) induced cervical dysplasia

The p16/INK4A protein is a cellular regulatory polypeptide over-expressed in the presence of high levels of the Human Papillomavirus (HPV) coded E7 protein. This review outlines the use of p16 antigen staining in cervical biopsies as well as in PAP smears summarizing the corresponding literature and commenting the authors’ own experience. The p16 antigen is a reliable marker for dysplastic cells in CINII/CINIII (HSIL) lesions as viewed in cervical biopsies. When PAP smears were examined at large scale screening for p16 antigenreactive and atypical cells, considerable variations could be found especially in ASCUS graded lesions. Therefore, the presence of p16-reactive atypical cells in PAP smears should be interpreted together with the cytological signs of dysplasia, such as the altered N/C ratio. In addition, women revealing p16-positive ASCUS/LSIL specimens should be examined for the presence of HPV DNA. Detection of HPV DNA alone, i.e. in the absence of cytological screening has a low predictive value, since the clearance of HPV may occur even in the absence of morphological alterations. Combined cytological as well as molecular follow up contributes to the efficiency of diagnostic and increases the probability of correct interpretation of the pre-cancerous lesions by non-invasive techniques.

Detection of HPV-induced cervical (pre) neoplastic lesions: a tissue microarray (TMA) study

The aim of this study was to evaluate the usefulness of a panel of biomarkers in the characterization of human papillomavirus (HPV)-induced cervical lesions. Management of these lesions depends on their histologic confirmation. Misinterpretation especially for benign mimics results in a significant diagnostic disagreement. For these reasons, a continuous effort is still needed to discover surrogate markers, which could support the final diagnosis. Archival biopsies of normal ectocervical and endocervical tissues, squamous metaplasia, cervical intraepithelial neoplasia (CIN), squamous cell carcinoma, adenocarcinoma in situ, and adenocarcinoma were retrieved to perform a tissue microarray (TMA). A panel of markers was tested on the TMA obtained slides by in situ hybridization (HPV DNA) and immunohistochemistry (p16, involucrin, Ki-67, and HPV L1 proteins). The sensitivity to detect high-risk HPV DNA increased with lesion's severity. In situ hybridization signals suggesting integrated viral physical status predominated in CIN II/III, squamous cell carcinoma, and glandular (pre) neoplastic lesions. The p16 and Ki-67 protein expression increased from CIN I to CIN III and to infiltrative lesions. Involucrin positivity was better appreciated in well-differentiated diagnostic entities (ectocervix, mature metaplasia, and CIN I). HPV L1 antibody detected the viral capsid protein in a low proportion of CIN I and II. In conclusion, using a panel of cervical biomarkers improves the final reporting of various HPV-induced epithelial lesions. Carefully constructed TMA with single spots of 1-mm diameter are powerful tools, which have a high reliability in representing full tissue sections.

Biomarker (ProEx C, p16(INK4A), and MiB-1) distinction of high-grade squamous intraepithelial lesion from its mimics

Topoisomerase IIalpha and minichromosome maintenance protein 2 are proteins associated with aberrant S-phase induction. The current study evaluated the performance of these biomarkers (ProEx C; TriPath Oncology, Burlington, NC) compared with p16(INK4A) and MiB-1 in distinguishing high-grade squamous intraepithelial lesions (HSILs) from HSIL mimics. We collected archival cervical biopsy, cone, and curettage specimens from 96 cases in which the differential diagnosis of HSIL vs reactive epithelial changes was considered. Hematoxylin- and eosin-stained slides were reviewed independently by three pathologists and scored for the presence or absence of SIL. Immunostains for ProEx C, p16, and MiB-1 were available for 95, 96, and 59 samples, respectively, and classified blinded to histological interpretation. Strong nuclear and cytoplasmic staining for p16 and staining for MiB-1 and ProEx C that extended beyond the lower one-third of the epithelium were scored as positive. Chi(2)-tests and receiver operating characteristic analysis were conducted to statistically compare biomarker immunostaining performance against majority histological interpretation of SIL. Agreement between pathologists was also assessed by the kappa-statistic. Inter-observer agreement ranged from fair to moderate (kappa=0.37-0.57). All three biomarkers correlated strongly with the majority diagnosis of SIL (P<0.001). Positive staining for ProEx C, p16, and MiB-1 was observed in 87% (N=52/60), 84% (N=51/61), and 94% (34/36), respectively, of SIL and negative in 71% (N=25/35), 63% (N=22/35), and 52% (N=12/23), respectively, of majority diagnoses of NoSIL. The combination of p16/ProEx C predicted more SIL (92%, N=33/36) and NoSIL (61%, N=14/23) than p16 plus MiB-1 (94%, N=34/36 and 43%, N=10/23), although this difference was not statistically significant. ProEx C appears to provide an equivalent level of sensitivity and a higher level of specificity for HSIL alone or in conjunction with p16. Its principal value may be in providing a lower false positive rate for NoSIL relative to MiB-1.

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.

Positive association between STAT3 and Ki-67 in cervical intraepithelial neoplasia

Signal transducer and activator of transcription 3 (STAT3) has been regarded as an oncogene in many types of cancers. However, its role in cervical carcinogenesis is not well determined. The purpose of this study was to evaluate the expression patterns of STAT3 in cervical intraepithelial neoplasia (CIN), normal cervix (NC), and squamous cell carcinoma (SCC) to explore its possible role in cervical carcinogenesis. Paraffin-embedded sections from 83 patients including 20 CIN 1, 10 CIN 2, 26 CIN 3, and 27 comparative cases of 10 NC and 17 stage Ib SCC were collected in this study. Immunohistochemistry was performed to analyze the expression patterns of STAT3, and the results obtained were categorized by a semiquantitative method and were further correlated with the CIN histopathologic grade and the proliferation marker, Ki-67, using the chi2 test. Our results showed that nuclear STAT3 expression was predominantly in the squamous epithelial cells, and that high-grade CIN and stage Ib SCC lesions had a higher nuclear STAT3 expression when compared with NC and CIN 1. Furthermore, the nuclear STAT3 expression in CIN was significantly correlated with Ki-67 expression (p = 0.025), but not CIN lesion grade. In summary, our results indicate that an altered STAT3 expression in CIN is correlated with cell proliferation but may not have a direct contribution to cervical carcinogenesis.

An armamentarium of wart treatments

Patients and clinicians experience the frustration of cutaneous viral warts caused by infection with the human papilloma virus (HPV).Warts appear in various forms on different sites of the body and include common warts (verruca vulgaris), plane or flat warts, myrmecia, plantar warts, coalesced mosaic warts, filiform warts, periungual warts, anogenital warts (venereal or condyloma acuminata), oral warts and respiratory papillomas. Cervical infection with HPV is now known to cause cervical cancer if untreated. A review of the medical literature reveals a huge armamentarium of wart monotherapies and combination therapies. Official evidence-based guidelines exist for the treatment of warts, but very few of the reported treatments have been tested by rigorous blinded, randomized controlled trials.Therefore, official recommendations do not often include treatments with reportedly high success rates, but they should not be ignored when considering treatment options. It is the purpose of this review to provide a comprehensive overview of the wart treatment literature to expand awareness of the options available to practitioners faced with patients presenting with problematic warts.

Expression of p16(INK4a) in relation to histopathology and viral load of 'high-risk' HPV types in cervical neoplastic lesions

A total of 91 cervical archival biopsy series were analysed for the presence and viral load of 'high-risk' types of human papillomavirus (HR-HPV), and p16(INK4a) expression. The women had various degrees of CIN (cervical intraepithelial neoplasia). HPV 16 was the most prevalent type found, at 47% frequency. The frequency of HPV 16 increased with increasing immunoreactivity to p16(INK4a), from 39% to 44% at cases scored low to medium, to 65% at high reactivity. Thirty (33%) of the samples had negative p16(INK4a) analysis results, but were positive for HR-HPV. There was no significant correlation between viral load and the level of p16(INK4a) expression, while the grade of CIN correlated to such expressions. Thus, p16(INK4a) expression analysis yielded information which is consistent with results from the histopathology and might complement the HPV analysis in a clinical prognostic procedure in order to find women at risk for cervical cancer.

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.

Impact of utilizing p16INK4A immunohistochemistry on estimated performance of three cervical cancer screening tests

The histopathological diagnosis of cervical intraepithelial neoplasia grade 2,3 (CIN 2,3) is subjective and prone to variability. In our study, we analyzed the impact of utilizing a biomarker (p16(INK4A)) together with histopathology to refine the "gold standard" utilized for evaluating the performance of 3 different cervical cancer screening tests: cervical cytology, human papillomavirus (HPV) DNA testing and visual inspection with acetic acid (VIA). Cervical biopsies from 2 South African cervical cancer screening studies originally diagnosed by a single pathologist were reevaluated by a second pathologist and a consensus pathology diagnosis obtained. Immunohistochemical staining for p16(INK4A) was then performed. The estimated sensitivity of some cervical cancer screening tests was markedly impacted by the criteria utilized to define CIN 2,3. Use of routine histopathology markedly underestimated the sensitivity of both conventional cytology and HPV DNA testing compared to an improved gold standard of consensus pathology and p16(INK4A) positivity. In contrast, routine histopathology overestimated the sensitivity of VIA. Our results demonstrate that refining the diagnosis of CIN 2,3 through the use of consensus pathology and immunohistochemical staining for p16(INK4A) has an important impact on measurement of the performance of cervical cancer screening tests. The sensitivity of screening tests such as HPV DNA testing and conventional cytology may be underestimated when an imperfect gold standard (routine histopathology) is used. In contrast, the sensitivity of other tests, such as VIA, may be overestimated with an imperfect gold standard.

Cell cycle and/or proliferation markers: what is the best method to discriminate cervical high-grade lesions?

The aim of this study on a series of biopsies diagnosed as normal, metaplastic, low-grade squamous intraepithelial lesions (LSILs), and high-grade squamous intraepithelial lesions (HSILs) was dual: to determine the chronology of cell cycle and proliferation abnormalities after human papillomavirus infection during the development of squamous intraepithelial lesions and to determine the best diagnostic indicator(s) linked to the appearance of an HSIL. Ninety-nine cervical biopsies, 18 normal, 9 with metaplastic changes, 29 LSIL, and 43 HSIL (23 cervical intraepithelial neoplasia 2 and 20 cervical intraepithelial neoplasia 3), were analyzed by image cytometry for DNA ploidy and p16INK4A determination, AgNOR counting, MIB-1, and ICBP90 immunostaining quantification. The human papillomavirus status had been previously determined on corresponding cytological smears with the Hybrid Capture II test. Suspect DNA profile and p16INK4A staining were the first significant events that preceded the increase of cell proliferation. Indeed, these markers were the best tests for the detection of a lesion, whatever its grade (positive predictive values of 90% and 100%, respectively). The presence of MIB-1- or ICBP90-positive cells in the upper two thirds of the epithelium was a very accurate feature to select HSIL (sensitivity, 100% for MIB-1) but with a low specificity. The sensitivity of a suspect DNA profile associated with a positive MIB-1 or ICPB90 immunostaining for the detection of an HSIL was, respectively, 92.8% and 92.7%; their specificities were 54.2% and 44%; their positive predictive values were 78% and 73%; their negative predictive values were 81.2% and 78.6%; and the global values were 78.8% and 74.3%. Thus, the most accurate test to distinguish an LSIL from an HSIL was the association of a suspect DNA profile and the presence of MIB-1- or ICBP90-positive cells in the upper two thirds of the epithelium.

MIB-1 and PCNA immunostaining as a diagnostic adjunct to cervical Pap smear

The present study was done to determine the role of MIB-1 (Molecular Immunology Borstel) and proliferating cell nuclear antigen (PCNA) proliferative index as a diagnostic adjunct to cervical Papanicolaou (Pap) smear for the identification of ascending grades of cervical intraepithelial neoplasia (CIN) developing into cancer in the human uterine cervix. A total of 49 adequate Pap smears with consensus diagnosis were destained for immunocytochemical staining (MIB-1 and PC10). Staining was done by streptavidin-biotin method after antigen retrieval. MIB-1 and PC10 labeling index (LI) were calculated in each case and divided into three groups, i.e., <10%, 10-20%, and >20%, respectively. Statistical analysis was done by using the SPSS 10.0 package. The comparisons were made using analysis of variance (ANOVA) and independent sample t-test. Bivariate and Pearson's correlation coefficient were used to obtain correlations between different groups. Out of 49 cases, 40 cases (81.6%) showed positive immunostaining with MIB-1 and PCNA. Proliferative LI of MIB-1 and PCNA increased with the ascending grades of CIN lesions to carcinoma. The highest proliferative index (mean +/- SD) for PCNA and MIB-1 were observed for the carcinoma group (PCNA LI, 39.200 +/- 1.6865; MIB-1LI, 35.300 +/- 1.8886). A significant positive correlation between ascending grades of squamous intraepithelial lesion (SIL) and labeling indices of markers (r = 0.87 for MIB-1 and r = 0.88 for PCNA) suggests that MIB-1/PCNA proliferative markers can be used as an adjunct to cytomorphological interpretation of conventional cervical Pap smear.

Immunocytochemical expression of p16INK4A and Ki-67 in cytologically negative and equivocal pap smears positive for oncogenic human papillomavirus

This study was designed to analyze the cross-sectional comparison of the p16 and Ki-67 immunocytochemical expression in negative and equivocal (atypical squamous cells of undetermined significance (ASC-US)) liquid-based cytology (LBC) samples testing positive for high-risk human papillomavirus (HPV) types with HC2 assay or polymerase-chain reaction (PCR). A series of 199 consecutive LBC specimens derived from the same number of women participating in the ongoing Latin American Screening Study at Leonor Mendes de Barros Hospital, Sao Paulo, were analyzed using immunocytochemistry for expression of p16 and Ki-67 in negative and equivocal LBC samples testing positive for high-risk HPV types with hybrid capture II test (HC2) or PCR. All patients with at least one test positive (cytology, PCR, and/or HC2) were followed each 6 months for 3 years. The follow-up procedure consisted of visual examination, colposcopic inspection, cytology, and HC2 assay. Among the negative cytologic samples, 101 were HPV-positive and 55 HPV-negative. Of the HPV-positive group, 59 of 101 cases (58.4%) were positive for both p16 and Ki67 immunostaining, and 17 of 101 (16.8%) were negative for both. The proportion of Ki-67-positivity increased almost in parallel with the increasing grade of p16-positivity (p = 0.0001 for linear trend). In the HPV-negative group, both markers were negative in 41 of 55 cases (74.5%), and no statistical relationship was observed between the two markers (Pearson, p = 0.595). HPV-positive ASC-US samples demonstrated a simultaneous positive immunoreaction for p16 and Ki67 in 11 of 16 cases (68.7%), whereas 3 (18.7%) were concurrently negative. The relationship between the two markers was of borderline significance (Pearson, p = 0.053), but no linear relationship was found between the graded p16 and Ki-67 expression (p = 0.065 for linear trend). In the HPV-negative ASC-US group, there was no statistical association between the graded p16 and Ki-67 positivity (Pearson, p = 0.281). After 36 months of follow-up of the ASC-US patients, 6 women still displayed ASC-US smear, of which 4 of 6 were HPV-positive and expressed both p16 and Ki-67 markers. Two of 43 ASC-US smears had high-grade squamous intraepithelial lesions diagnosed (4.6%), and 1 had low-grade squamous intraepithelial lesion (2.3%). All of those were positive for HPV, p16 and Ki-67. Patients with ASC-US diagnosis and positive high-risk HPV status and positive for p16 Ki67 should be carefully observed to exclude occurrence of a squamous intraepithelial lesion. The combination of these two markers can be a useful implement for management of women with equivocal cytology.

P16INK4a expression and progression risk of low-grade intraepithelial neoplasia of the cervix uteri

The aim of the study was to evaluate the immunohistochemical expression of p16INK4a as a marker of progression risk in low-grade dysplastic lesions of the cervix uteri. p16INK4a immunohistochemistry was performed on 32 CIN1 with proven spontaneous regression of the lesion in the follow-up (group A), 31 (group B) with progression to CIN3 and 33 (group C) that were randomly chosen irrespective of the natural history of the lesion. p16INK4a staining pattern was scored as negative (less than 5% cells in the lower third of dysplastic epithelium stained), as focally positive (< or = 25%) and as diffuse positive (> 25%). A diffuse staining pattern was detected in 43.8% of CIN1 of group A, 74.2% of group B and 56.3% of group C. No p16INK4a staining was detected in 31.3% and 12.9% CIN1 lesions of groups A and B, respectively. Overall, 71.4% and 37.8% of p16INK4a-negative and diffusely positive CIN1 had regressed at follow-up, whereas 28.6% and 62.2% negative and diffusely positive CIN1 were progressed to CIN3, respectively (P < 0.05). All CIN3 lesions analyzed during follow-up of group B were diffusely stained for p16INK4a. Although p16INK4a may be expressed in low-grade squamous lesions that undergo spontaneous regression, in this study, CIN1 cases with diffuse p16INK4a staining had a significantly higher tendency to progress to a high-grade lesion than p16INK4a-negative cases. p16INK4a may have the potential to support the interpretation of low-grade dysplastic lesions of the cervix uteri.

The Ki-67 Labeling Index Is Not a Useful Predictor for the Follow-up of Cervical Intraepithelial Neoplasia 1

OBJECTIVE

Our aim was to determine whether the Ki-67 immunostaining pattern, present on diagnosis of cervical intraepithelial neoplasia (CIN), predicts the change from low-grade to high-grade CIN over a 2-year period after diagnosis.

MATERIALS AND METHODS

Of 59 cervical biopsy samples from 59 patients diagnosed as having cervical CIN, 35 were diagnosed as CIN 1 and 24 were diagnosed as CIN 2 or CIN 3. The Ki-67 immunostain showed immunopositive cells in the upper two thirds of the epithelium in all specimens. Two hundred nuclei were counted in 25 high-power fields in each specimen, including all of the epithelial layers, to determine the mean number of Ki-67-positive cells. In situ hybridization was used to demonstrate and type human papillomavirus. The chi test, Fisher exact test, Student t test, one-way analysis of variance, and Tukey test were used for statistical analysis, with significance set at p < .05.

RESULTS

The mean Ki-67 labeling index for CIN 1, CIN 2, CIN 3, and CIN 2,3 were, respectively, 32.5%, 43.2%, 53.2%, and 47.8%. The statistical study showed significant differences between CIN 1 versus CIN 2, CIN 1 versus CIN 3, and CIN 1 versus CIN 2,3. For CIN 1, the mean Ki-67 labeling index was 32.8% when the lesion disappeared and was 34.6% for persisting lesions. There was no statistically significant difference.

CONCLUSIONS

Ki-67 labeling index did not predict persisting CIN 1.

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.

Usefulness of liquid-based cytology specimens for the immunocytochemical study of p16 expression and human papillomavirus testing

BACKGROUND

In cervical lesions, the overexpression of p16 is reported to be closely associated with high-risk human papillomavirus (HPV) infection. The objective of the current study was to confirm the usefulness of liquid-based cervical specimens for p16 staining as well as tissue sections.

METHODS

A total of 98 patients with cervical lesions were entered into the current study. After the cytologic examination using liquid-based cervical smears, the same slides were immunostained for p16 and were compared with slides of simultaneously obtained, immunohistologically stained tissue sections. Moreover, the status of the HPV infection was examined by polymerase chain reaction using residual cytologic samples.

RESULTS

Using liquid-based Pap smears, 98 cases were diagnosed as atypical squamous cells of undetermined significance (38 cases), low-grade squamous intraepithelial lesion (12 cases), high-grade squamous intraepithelial lesion (HSIL) (33 cases), and invasive carcinoma (15 cases). The concordance rate between the cytologic and histologic diagnoses was found to be higher in high-grade lesions compared with low-grade lesions. Immunohistochemistry revealed that all HSIL and invasive carcinoma cases contained p16-positive cells in the liquid-based Pap smears and diffuse p16 staining was observed in all high-grade lesions with greater than CIN Grade 3 cervical intraepithelial neoplasia except for two adenocarcinoma cases. Of the 98 cases, 60 were found to be positive for high-risk HPV and 55 of these 60 HPV-positive cases were found to be p16 positive on cytologic examination. There were 16 cases that demonstrated marked discrepancies between the cytologic and histologic diagnoses.

CONCLUSIONS

The results of the current study confirmed that the immunohistochemical detection of p16 was more sensitive and specific than HPV status in cervical lesions using a liquid-based method as well as tissue samples, suggesting that p16 should be used as a satisfactory biomarker for the primary screening of cervical cytology.