Is p16INK4A expression more useful than human papillomavirus test to determine the outcome of atypical squamous cells of undetermined significance-categorized Pap smear? A comparative analysis using abnormal cervical smears with follow-up biopsies

Artificial intelligence-assisted fast screening cervical high grade squamous intraepithelial lesion and squamous cell carcinoma diagnosis and treatment planning

Every year cervical cancer affects more than 300,000 people, and on average one woman is diagnosed with cervical cancer every minute. Early diagnosis and classification of cervical lesions greatly boosts up the chance of successful treatments of patients, and automated diagnosis and classification of cervical lesions from Papanicolaou (Pap) smear images have become highly demanded. To the authors' best knowledge, this is the first study of fully automated cervical lesions analysis on whole slide images (WSIs) of conventional Pap smear samples. The presented deep learning-based cervical lesions diagnosis system is demonstrated to be able to detect high grade squamous intraepithelial lesions (HSILs) or higher (squamous cell carcinoma; SQCC), which usually immediately indicate patients must be referred to colposcopy, but also to rapidly process WSIs in seconds for practical clinical usage. We evaluate this framework at scale on a dataset of 143 whole slide images, and the proposed method achieves a high precision 0.93, recall 0.90, F-measure 0.88, and Jaccard index 0.84, showing that the proposed system is capable of segmenting HSILs or higher (SQCC) with high precision and reaches sensitivity comparable to the referenced standard produced by pathologists. Based on Fisher's Least Significant Difference (LSD) test (P < 0.0001), the proposed method performs significantly better than the two state-of-the-art benchmark methods (U-Net and SegNet) in precision, F-Measure, Jaccard index. For the run time analysis, the proposed method takes only 210 seconds to process a WSI and is 20 times faster than U-Net and 19 times faster than SegNet, respectively. In summary, the proposed method is demonstrated to be able to both detect HSILs or higher (SQCC), which indicate patients for further treatments, including colposcopy and surgery to remove the lesion, and rapidly processing WSIs in seconds for practical clinical usages.

Cervical, Ovarian and Endometrial Tumor Markers: Potential Clinical Value

Tumors markers can be described as molecular products expressed by neoplasia tissues (immunohistochemistry), or metabolized and secreted by tumor and characterized biochemically in body fluids such as blood and urine. They may have utility as indicators of tumor stage and grade as well useful for monitoring responses to treatment and predicting recurrence, progression, development of metastases, or even patient survival. Unfortunately, in some cases they may have no identified clinical potential. Several investigations have been carried out, especially in the last decade, using biotechnological methods, in order to identify new potential tumor markers. By translating these findings into clinical use one may facilitate accurate diagnosis and prognostic prediction, and contribute to individualized treatment. The objective of this review is to describe some biomarkers with potential use in clinical settings of uterine cervix, ovary, and endometrium carcinomas.

Meta-analysis of the accuracy of p16 or p16/Ki-67 immunocytochemistry versus HPV testing for the detection of CIN2+/CIN3+ in triage of women with minor abnormal cytology

BACKGROUND

Women with atypical squamous cells of undetermined significance (ASC-US) can be triaged accurately with a high-risk human papillomavirus (hrHPV) test to identify those who need a referral. However, the triage of low-grade squamous intraepithelial lesion (LSIL) with hrHPV testing has very low specificity. Overexpression of p16, with or without Ki-67, indicates neoplastic transformation of human papillomavirus-infected cervical cells and may more accurately predict underlying cervical intraepithelial neoplasia of grade 3 or worse (CIN3+).

METHODS

A literature search was conducted in 3 bibliographic databases. Studies were selected if they included women with ASC-US or LSIL who were triaged with dual staining (p16/Ki-67) and/or p16 staining and, if available, with a comparator hrHPV test to detect cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) or CIN3+.

RESULTS

Thirty-eight studies were eligible. The sensitivity of p16 staining for CIN3+ was significantly lower than that of hrHPV DNA testing (ratio for ASC-US, 0.87; 95% confidence interval [CI], 0.78-0.97; ratio for LSIL, 0.86; 95% CI, 0.80-0.93). In contrast, the specificity of p16 staining was substantially higher with relative specificities of 1.60 (95% CI, 1.35-1.88) and 2.29 (95% CI, 2.05-2.56) for ASC-US and LSIL respectively. Dual staining was as sensitive as hrHPV DNA testing but was more specific (ratio for ASC-US, 1.65; 95% CI, 1.42-1.92; ratio for LSIL, 2.45; 95% CI, 2.17-2.77).

CONCLUSIONS

This meta-analysis confirms that p16 staining and p16/Ki-67 staining are more specific for CIN2+/CIN3+ than hrHPV DNA testing. Although p16 staining is less sensitive for CIN3+ than hrHPV DNA testing, dual staining has similar sensitivity.

Prevention of Cervical Cancer: Guideline of the DGGG and the DKG (S3 Level, AWMF Register Number 015/027OL, December 2017) - Part 2 on Triage, Treatment and Follow-up

Aims Annual opportunistic screening for cervical carcinoma has been done in Germany since 1971. The creation of this S3 guideline meets an important need, outlined in the National Cancer Plan, with regard to screening for cervical cancer, as this guideline aims to provide important information and support for planned organized screening for cervical cancer in Germany. Methods With the financial support of German Cancer Aid, 21 professional societies developed evidence-based statements and recommendations (classified using the GRADE system) for the screening, management and treatment of precancerous conditions of the cervix. Two independent scientific institutes compiled systematic reviews for this guideline. Recommendations The second part of this short summary deals with the triage, treatment and follow-up care of cervical dysplasia. With regard to those women who do not participate in screening, the guideline authors recommend sending out repeat invitation letters or an HPV self-collection kit. Colposcopy should be carried out for further investigation if cytology findings are Pap II-p and HPV test results are positive or if the results of an HPV 16 or HPV 18 screening test are positive. A single abnormal Pap smear should be triaged and investigated using HPV testing or p16/Ki67 dual staining.

Management of HPV-related cervical disease: role of p16INK4a immunochemistry. Review of the literature

This systematic review of 43 studies aims to evaluate the absolute and relative sensitivity and specificity of p16INK4a with regard to uterine cervix lesions, describing innovations and techniques for the detection of high-grade cervical dysplasia and allowing correct treatment. Studies were identified in the PubMed database up to March 2015. The keywords hrHPV, p16INK4a gene, and uterine cervical disease (MeSH terms) were used. Only English-language articles were included. We considered retrospective and prospective studies that assessed p16INK4a or p16INK4a/Ki67 staining, with or without HPV-DNA testing (HC2/PCR) as a comparator test, in cytological/histological specimens for which the diagnosis of ASCUS, LSIL or HSIL was verified with a reference standard. The primary outcome for cervical lesions was evaluation of the absolute p16INK4a immunoreactivity; the secondary outcome was evaluation of the relative p16INK4a immunoreactivity versus HPV testing in those studies where comparator tests were available. p16INK4a was more specific than HPV-DNA test (median values of 56.1% vs. 52.25% in CIN grade ≥2 lesions; 82.5% vs. 53% in negative and CIN grade ≥1 lesions). The main limitation of this study is linked to both qualitative and quantitative p16INK4a levels of expression, while the second limitation is the lack of standardized scales. p16INK4a and HPV-DNA used together increased the sensitivity and negative predictive value for CIN detection. p16INK4a can be considered a biomarker of CIN2 or CIN3, indicating a high risk of relapse or evolution to invasive carcinoma. Also p16INK4a-negative CIN should be considered and further research should be performed.

The Impact of HPV as an Etiological Factor in Gynecological and Oropharyngeal Cancer

The human papilloma virus (HPV) is one of several viral pathogens linked to human cancer. This article reviews the current worldwide cancer burden related to this pathogen. The article also examines the role of HPV in oropharyngeal and gynecological malignancies, current treatment implications, and future directions in the treatment and prevention of HPV-related disease.

Predictive value of p16/Ki-67 immunocytochemistry for triage of women with abnormal Papanicolaou test in cervical cancer screening: a systematic review and meta-analysis

BACKGROUND

The Papanicolaou (Pap) test is one screening strategy used to prevent cervical cancer in developed countries. The p16/Ki-67 immunocytochemistry is a triage test performed on Pap smears in women with atypical squamous cells of undetermined significance (ASCUS) or low grade squamous intraepithelial lesion.

OBJECTIVE

Our objective was to review studies investigating the diagnostic performance of p16/Ki-67 dual stain for triage of women with abnormal Pap tests.

DESIGN

We conducted a systematic review and meta-analysis of diagnostic test accuracy studies.

SETTINGS

We followed the protocol of systematic review of diagnostic accuracy studies.

PATIENTS AND METHODS

We searched PubMed, The Cochrane Library, BioMed Central, and ClinicalTrials.gov for relevant studies. We included research that assessed the accuracy of p16/Ki-67 dual stain and high risk human papillomavirus testing for triage of abnormal Pap smears. Review articles and studies that provided insufficient data to construct 2.2 tables were excluded. Data synthesis was conducted using a random-effects model.

MAIN OUTCOME MEASURES

Sensitivity and specificity.

RESULTS

In seven studies encompassing 2628 patients, the pooled sensitivity and specificity of p16/Ki-67 for triage of abnormal Pap smear results were 0.91 (95% CI, 0.89 to 0.93) and 0.64 (95% CI, 0.62 to 0.66), respectively. No study used a case-control design. A subgroup analysis involving liquid-based cytology showed a sensitivity of 0.91 (95%CI, 0.89 to 0.93) and specificity of 0.64 (95%CI, 0.61 to 0.66).

CONCLUSIONS

Our meta-analysis of p16/Ki-67 dual stain studies showed that the test achieved high sensitivity and moderate specificity for p16/Ki-67 immunocytochemistry for high-grade squamous intraepi.thelial lesion and cervical cancer. We suggest that p16/Ki-67 dual stain might be a reliable ancillary method identifying high-grade squamous intraepithelial lesions in women with abnormal Pap tests.

LIMITATIONS

No study in the meta-analysis examined the accuracy of the p16/Ki-67 dual stain for inter.pretation of glandular neoplasms.

Value of PAX1 Methylation Analysis by MS-HRM in the Triage of Atypical Squamous Cells of Undetermined Significance

BACKGROUND

Detection of cervical high grade lesions in patients with atypical squamous cells of undetermined significance (ASCUS) is still a challenge. Our study tested the efficacy of the paired boxed gene 1 (PAX1) methylation analysis by methylation-sensitive high-resolution melting (MS-HRM) in the detection of high grade lesions in ASCUS and compared performance with the hybrid capture 2 (HC2) human papillomavirus (HPV) test.

MATERIALS AND METHODS

A total of 463 consecutive ASCUS women from primary screening were selected. Their cervical scrapings were collected and assessed by PAX1 methylation analysis (MS-HRM) and high-risk HPV-DNA test (HC2). All patients with ASCUS were admitted to colposcopy and cervical biopsies. The Chi- square test was used to test the differences of PAX1 methylation or HPV infection between groups.

RESULTS

The specificity, sensitivity, and accuracy for detecting CIN2 + lesions were: 95.6%, 82.4%, and 94.6%, respectively, for the PAX1 MS-HRM test; and 59.7%, 64.7%, and 60.0% for the HC2 HPV test.

CONCLUSIONS

The PAX1 methylation analysis by MS-HRM demonstrated a better performance than the high-risk HPV-DNA test for the detection of high grade lesions (CIN2 +) in ASCUS cases. This approach could screen out the majority of low grade cases of ASCUS, and thus reduce the referral rate to colposcopy.

p16 Immunohistochemistry is useful in confirming high-grade squamous intraepithelial lesions (HSIL) in women with negative HPV testing

SUMMARY

It is believed that almost all squamous cell carcinomas of the cervix are associated with HR-HPV infection. However, a subset of high-grade squamous intraepithelial lesion (HSIL) (CIN2 and CIN3) lesions is found in those women with negative HPV testing. Knowledge of HPV status can influence pathologists' decision in rendering the diagnosis of cervical squamous intraepithelial lesions (SIL). p16, a surrogate marker for HSIL, has been widely applied to facilitate accurate diagnosis of HPV-related cervical dysplasia, especially CIN2 and CIN3. To assess whether p16 immunostaining is useful in diagnosing HSIL in women with negative HPV testing, we studied the utility of p16 immunohistochemistry in 46 women of HSIL and HPV-negative status. A total of 46 cases of initial biopsies with histopathologically diagnosed HSIL (CIN2 and CIN3) were identified from our hospital archives. All women were HPV negative with at least 1 HPV testing using HC-II (Qiagen) within 6 mo of initial biopsy. LEEP procedures within 6 mo of initial biopsies were reviewed and documented. Immunohistochemical staining of p16 was performed on recuts of all original biopsies. Some LEEP specimens without evidence of HSIL (CIN2 and CIN3) on hematoxylin and eosin had recuts with deeper levels and p16 immunostaining to confirm the negative diagnosis. p16 immunostaining were evaluated as negative, focal/patchy, or diffuse staining pattern. Patients' HPV testing status and related clinicopathologic information were reviewed, tabulated, and correlated with p16 immunostaining patterns. Forty-six women between the age of 17 and 58 yr, with a median of 35 yr, were all HPV-negative. All women, except 2, had an abnormal cytologic interpretation at the time of HPV testing ranging from ASC-US to HSIL. Forty-two women (91.3%) had LEEP procedures done within 6 mo of the initial biopsies. LEEP specimens showed that 76.2% (32 cases) women had HSIL, including 22 cases of CIN2 and 10 cases of CIN3, 14.3% (6 cases) had low-grade squamous intraepithelial lesion (CIN1), and 9.5% (4 cases) had benign cervix. p16 immunostaining, performed on initial biopsies with histopathologic diagnoses of CIN2 or CIN3, showed that 66.7% (28 cases) had diffuse staining pattern, 16.7% (7 cases) had focal/patchy pattern, and 16.7% (7 cases) had negative p16 staining. On LEEP follow-up, all 28 cases with diffuse p16 staining pattern had HSIL (CIN2 and CIN3), and all 7 cases with negative p16 staining had no detectable high-grade dysplasia. For those 7 cases with focal/patch p16 staining pattern, 4 had HSIL (CIN2) and 3 had low-grade squamous intraepithelial lesion (CIN1) on LEEP follow-up. Approximately 76% of women with negative HPV and diagnosis of HSIL (CIN2 and CIN3) on initial biopsy had confirmed HSIL (CIN2 and CIN3) in subsequent LEEP follow-up. Diffuse p16 immunostaining pattern is the hallmark of HSIL because it correlates 100% with CIN2 and CIN3 lesions between initial biopsy and LEEP specimens, regardless of the HPV status. The negative predictive value for p16 immunoreactivity to predict cervical lesions less than high grade is almost 100% in our study. Our study suggests that when a woman is negative for HPV and also negative for p16, diagnosis of HSIL should be very cautious in void of unnecessary LEEP procedures.

The Application of Classification and Regression Trees for the Triage of Women for Referral to Colposcopy and the Estimation of Risk for Cervical Intraepithelial Neoplasia: A Study Based on 1625 Cases with Incomplete Data from Molecular Tests

OBJECTIVE

Nowadays numerous ancillary techniques detecting HPV DNA and mRNA compete with cytology; however no perfect test exists; in this study we evaluated classification and regression trees (CARTs) for the production of triage rules and estimate the risk for cervical intraepithelial neoplasia (CIN) in cases with ASCUS+ in cytology.

STUDY DESIGN

We used 1625 cases. In contrast to other approaches we used missing data to increase the data volume, obtain more accurate results, and simulate real conditions in the everyday practice of gynecologic clinics and laboratories. The proposed CART was based on the cytological result, HPV DNA typing, HPV mRNA detection based on NASBA and flow cytometry, p16 immunocytochemical expression, and finally age and parous status.

RESULTS

Algorithms useful for the triage of women were produced; gynecologists could apply these in conjunction with available examination results and conclude to an estimation of the risk for a woman to harbor CIN expressed as a probability.

CONCLUSIONS

The most important test was the cytological examination; however the CART handled cases with inadequate cytological outcome and increased the diagnostic accuracy by exploiting the results of ancillary techniques even if there were inadequate missing data. The CART performance was better than any other single test involved in this study.

Specific type epigenetic changes in cervical cancers

Cancer is a genetic and epigenetic disease. Multiple genetic and epigenetic changes have been studied in cervical cancer; however, such changes are selected for during tumorigenesis and tumor aggression is not yet clear. Cervical cancer is a multistep process with accumulation of genetic and epigenetic alterations in regulatory genes, leading to activation of oncogenes and inactivation or loss of tumor suppressor genes. In cervical cancer, epigenetic alterations can affect the expression of papillomaviral as well as host genes in relation to stages representing the multistep process of carcinogenesis.

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.

Human papillomavirus testing versus repeat cytology for triage of minor cytological cervical lesions

BACKGROUND

Atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intra-epithelial lesions (LSIL) are minor lesions of the cervical epithelium, detectable by cytological examination of cells collected from the surface of the cervix of a woman.Usually, women with ASCUS and LSIL do not have cervical (pre-) cancer, however a substantial proportion of them do have underlying high-grade cervical intra-epithelial neoplasia (CIN, grade 2 or 3) and so are at increased risk for developing cervical cancer. Therefore, accurate triage of women with ASCUS or LSIL is required to identify those who need further management.This review evaluates two ways to triage women with ASCUS or LSIL: repeating the cytological test, and DNA testing for high-risk types of the human papillomavirus (hrHPV) - the main causal factor of cervical cancer.

OBJECTIVES

Main objective To compare the accuracy of hrHPV testing with the Hybrid Capture 2 (HC2) assay against that of repeat cytology for detection of underlying cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) or grade 3 or worse (CIN3+) in women with ASCUS or LSIL. For the HC2 assay, a positive result was defined as proposed by the manufacturer. For repeat cytology, different cut-offs were used to define positivity: Atypical squamous cells of undetermined significance or worse (ASCUS+), low-grade squamous intra-epithelial lesions or worse (LSIL+) or high-grade squamous intra-epithelial lesions or worse (HSIL+).Secondary objective To assess the accuracy of the HC2 assay to detect CIN2+ or CIN3+ in women with ASCUS or LSIL in a larger group of reports of studies that applied hrHPV testing and the reference standard (coloscopy and biopsy), irrespective whether or not repeat cytology was done.

SEARCH METHODS

We made a comprehensive literature search that included the Cochrane Register of Diagnostic Test Accuracy Studies; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE (through PubMed), and EMBASE (last search 6 January 2011). Selected journals likely to contain relevant papers were handsearched from 1992 to 2010 (December). We also searched CERVIX, the bibliographic database of the Unit of Cancer Epidemiology at the Scientific Institute of Public Health (Brussels, Belgium) which contains more than 20,000 references on cervical cancer.More recent searches, up to December 2012, targeted reports on the accuracy of triage of ASCUS or LSIL with other HPV DNA assays, or HPV RNA assays and other molecular markers. These searches will be used for new Cochrane reviews as well as for updates of the current review.

SELECTION CRITERIA

Studies eligible for inclusion in the review had to include: women presenting with a cervical cytology result of ASCUS or LSIL, who had undergone both HC2 testing and repeat cytology, or HC2 testing alone, and were subsequently subjected to reference standard verification with colposcopy and colposcopy-directed biopsies for histologic verification.

DATA COLLECTION AND ANALYSIS

The review authors independently extracted data from the selected studies, and obtained additional data from report authors.Two groups of meta-analyses were performed: group I concerned triage of women with ASCUS, group II concerned women with LSIL. The bivariate model (METADAS-macro in SAS) was used to assess the absolute accuracy of the triage tests in both groups as well as the differences in accuracy between the triage tests.

MAIN RESULTS

The pooled sensitivity of HC2 was significantly higher than that of repeat cytology at cut-off ASCUS+ to detect CIN2+ in both triage of ASCUS and LSIL (relative sensitivity of 1.27 (95% CI 1.16 to 1.39; P value < 0.0001) and 1.23 (95% CI 1.06 to 1.4; P value 0.007), respectively. In ASCUS triage, the pooled specificity of the triage methods did not differ significantly from each other (relative specificity: 0.99 (95% CI 0.97 to 1.03; P value 0.98)). However, the specificity of HC2 was substantially, and significantly, lower than that of repeat cytology in the triage of LSIL (relative specificity: 0.66 (95% CI 0.58 to 0.75) P value < 0.0001).

AUTHORS' CONCLUSIONS

HPV-triage with HC2 can be recommended to triage women with ASCUS because it has higher accuracy (significantly higher sensitivity, and similar specificity) than repeat cytology. When triaging women with LSIL, an HC2 test yields a significantly higher sensitivity, but a significantly lower specificity, compared to a repeat cytology. Therefore, practice recommendations for management of women with LSIL should be balanced, taking local circumstances into account.

p16 expression is not associated with human papillomavirus in urinary bladder squamous cell carcinoma

Squamous cell carcinoma of the urinary bladder is unusual and of unknown etiology. There is a well-established association between human papillomavirus (HPV) infection and the development of cervical and head/neck squamous cell carcinomas. However, the role of HPV in the pathogenesis of squamous cell carcinoma of the urinary bladder is uncertain. The purposes of this study were to investigate the possible role of HPV in the development of squamous cell carcinoma of the urinary bladder and to determine if p16 expression could serve as a surrogate marker for HPV in this malignancy. In all, 42 cases of squamous cell carcinoma of the urinary bladder and 27 cases of urothelial carcinoma with squamous differentiation were investigated. HPV infection was analyzed by both in situ hybridization at the DNA level and immunohistochemistry at the protein level. p16 protein expression was analyzed by immunohistochemistry. HPV DNA and protein were not detected in 42 cases of squamous cell carcinoma (0%, 0/42) or 27 cases of urothelial carcinoma with squamous differentiation (0%, 0/15). p16 expression was detected in 13 cases (31%, 13/42) of squamous cell carcinoma and 9 cases (33%, 9/27) of urothelial carcinoma with squamous differentiation. There was no correlation between p16 expression and the presence of HPV infection in squamous cell carcinoma of the bladder or urothelial carcinoma with squamous differentiation. Our data suggest that HPV does not play a role in the development of squamous cell carcinoma of the urinary bladder or urothelial carcinoma with squamous differentiation. p16 expression should not be used as a surrogate marker for evidence of HVP infection in either squamous cell carcinoma of the urinary bladder or urothelial carcinoma with squamous differentiation as neither HVP DNA nor protein is detectable in these neoplasms.

Prevalence of human papilloma virus in cytological abnormalities: Association of risk factors and cytomorphological findings

Background:

Previous studies demonstrated the etiological role of human papilloma virus (HPV) in cervical carcinogenesis. Assessing the distribution of HPV may elucidate these observations.

Materials and Methods:

In total, we examined 3839 specimens, of which 187 abnormally classified cervical smears were immunostained using the p16^INK4A assay. DNA was extracted from 182 specimens, and polymerase chain reaction (PCR) was performed. Participants’ socio-demographics, sexual and reproductive history, HIV status, contraceptive use, and Pap smear history were recorded.

Results:

Subject ages, number of sexual partners, and age at first sexual encounter ranged from 15 to 49 years, from 1 to 37 partners, and from 13 to 34 years, respectively. P16 immunoreactivity was detected in 60.4% of cases. The distribution of epithelial lesions and P16 overexpression (bracketed) was: 28 (5) atypical squamous cells of undetermined significance (ASC-US), 96 (50) lower grade squamous intraepithelial lesion (LSIL), 9 (7) atypical squamous cells-cannot exclude HSIL (ASC-H), and 54 (51) higher grade squamous intraepithelial lesion (HSIL). Ninety-four percent of HSIL expressed P16. Fifty-two percent of LSIL expressed P16. P16 expression declined from 61% (25–34 year age group) to 5% (45–49 year age group) for different age groups. HPV-DNA by PCR was detected in 94.5% of P16-positive samples. Type-specific PCR (HPV 16 and 18) was found in 12.2% and 14.5% of abnormal lesions, respectively. Younger age at first sexual encounter and HIV infection predominated in HPV type(s) 16 and/or 18 positive subjects.

Conclusion:

This study reinforced the value of the p16^INK4A surrogate marker in identifying women with progressive cervical disease.

p16INK4a immunocytochemistry versus human papillomavirus testing for triage of women with minor cytologic abnormalities: a systematic review and meta-analysis

The best method for identifying women who have minor cervical lesions that require diagnostic workup remains unclear. The authors of this report performed a meta-analysis to assess the accuracy of cyclin-dependent kinase inhibitor 2A (p16(INK4a)) immunocytochemistry compared with high-risk human papillomavirus DNA testing with Hybrid Capture 2 (HC2) to detect grade 2 or greater cervical intraepithelial neoplasia (CIN2+) and CIN3+ among women who had cervical cytology indicating atypical squamous cells of undetermined significance (ASC-US) or low-grade cervical lesions (LSIL). A literature search was performed in 3 electronic databases to identify studies that were eligible for this meta-analysis. Seventeen studies were included in the meta-analysis. The pooled sensitivity of p16(INK4a) to detect CIN2+ was 83.2% (95% confidence interval [CI], 76.8%-88.2%) and 83.8% (95% CI, 73.5%-90.6%) in ASC-US and LSIL cervical cytology, respectively, and the pooled specificities were 71% (95% CI, 65%-76.4%) and 65.7% (95% CI, 54.2%-75.6%), respectively. Eight studies provided both HC2 and p16(INK4a) triage data. p16(INK4a) and HC2 had similar sensitivity, and p16(INK4a) has significantly higher specificity in the triage of women with ASC-US (relative sensitivity, 0.95 [95% CI, 0.89-1.01]; relative specificity, 1.82 [95% CI, 1.57-2.12]). In the triage of LSIL, p16(INK4a) had significantly lower sensitivity but higher specificity compared with HC2 (relative sensitivity, 0.87 [95% CI, 0.81-0.94]; relative specificity, 2.74 [95% CI, 1.99-3.76]). The published literature indicated the improved accuracy of p16(INK4a) compared with HC2 testing in the triage of women with ASC-US. In LSIL triage, p16(INK4a) was more specific but less sensitive.

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.

DNA methylation changes in cervical cancers

Cervical carcinoma is one of the major causes of death in women worldwide. It is difficult to foresee a dramatic increase in cure rate even with the most optimal combination of cytotoxic drugs, surgery, and radiation; therefore, testing of molecular targeted therapies against this malignancy is highly desirable. Cervical cancer is a multistep process with accumulation of genetic and epigenetic alterations in regulatory genes, leading to activation of oncogenes and inactivation or loss of tumor suppressor genes (TSGs). In the last decade, in addition to genetic alterations, epigenetic inactivation of TSGs by promoter hypermethylation has been recognized as an important and alternative mechanism in tumorigenesis. In cervical cancer, epigenetic alterations can affect the expression of papillomavirus as well as host genes in relation to stages representing the multistep process of carcinogenesis. Here we discuss these epigenetic alterations in cervical cancer focusing on DNA methylation.

The value of p16 in ASCUS cases: a retrospective study using frozen cytologic material

This study scans the efficacy of p16 immunostain on gynecological cytologies for the detection of high-grade lesions in ASCUS cases. This is a retrospective study that evaluates p16 immunostaining using frozen material from 109 cases diagnosed as ASCUS and followed for an average of 16 months. The diagnosis of ASCUS was made using liquid-based cytology (Thin Prep, Hologic, Marlborough, MA). High-risk HPV using Hybrid Capture II was performed. The immunohistochemical evaluation of p16 immunoreactivity was done following Wentzensen criteria. In the series p16 immunoreactivity showed a sensitivity and negative predictive value for HSIL, of 82.3 and 94.5% with specificity and positive predictive value of 100%. The sensitivity was similar to that found using the HC-II, though the specificity was much higher. The use of p16 immunostain in cytologic specimens applying the Wentzensen criteria helps to focus the attention in positive cells evaluating the cell changes, helps to detect some cells suspicious or diagnostic of HSIL, and could help to reclassify the ASCUS cases.

Prediction of clinical outcome using p16INK4a immunocytochemical expression in low-grade squamous intraepithelial lesions and high-risk HPV-positive atypical squamous cells of undetermined significance in patients with and without colposcopic evident cervical disease

p16INK4a as a diagnostic marker of a cervical intraepithelial neoplasia of grade 2+ (CIN2+) in atypical squamous cells of undetermined significance (ASC-US) and low-grade squamous intraepithelial lesion (LSIL) cytological samples has been analyzed, but has not yet been included in clinical routine practice. One hundred and ninety-one patients with an abnormal Pap test (84 ASC-US and 107 LSILs) who underwent colposcopy were selected for this study. At enrollment, 96 patients (Group 1) had a positive colposcopy and therefore underwent a cervical biopsy, while 95 (Group 2) had a negative colposcopy and were followed up for up to 1 year. Both groups were tested for p16INK4a using immunocytochemical methods, and the p16INK4a results were correlated with histology or follow-up outcome. In Group 1 ASC-US cases, 82% of lesions less than CIN2 were p16INK4a-negative and all CIN2 cases were p16INK4a-positive (p=0.00044). In Group 1 LSIL cases, 71% of lesions less than CIN2 were p16INK4a-negative and 87% of CIN2/3 were p16INK4a-positive (p=0.00033). Seventy-seven percent of Group 2 ASC-US patients with a negative 1-year follow-up (NF-U) were p16INK4a-negative at enrollment, while all patients with positive follow-up (PF-U) were p16INK4a-positive (p=0.00113). In Group 2 LSIL cases, 83% of patients with NF-U were p16INK4a-negative, while 65% of patients with PF-U were p16INK4a-positive at enrollment (p=0.0014). In fact, 39% of the positive p16INK4a LSIL patients had CIN2+ histological lesions. The positive predictive value of p16INK4a for CIN2+ was 50% in ASC-US and 52% in LSIL cases; the negative predictive value was 100 and 94%, respectively. In conclusion, in our patients, a negative p16INK4a appears to be a marker of the absence of CIN3, while a positive p16INK4a can be correlated with the presence of histological CIN2+ found at enrollment or during the subsequent follow-up. Thus, its clinical predictive value is independent from the colposcopic aspect at enrollment.

Triage of cervical cytological diagnoses of atypical squamous cells by DNA methylation of paired boxed gene 1 (PAX1)

Detection of cervical high-grade squamous intraepithelial lesions (HSIL) in patients with equivocal cytological abnormalities, such as atypical squamous cells (ASC) of undetermined significance (ASCUS) or inability to exclude high-grade squamous intraepithelial lesions (ASC-H) is still a challenge. This study tested the efficacy of PAX1 methylation analysis in the triage of cervical ASCUS and ASC-H and compared its performance with Hybrid Capture 2 (HC2) HPV test. A hospital-based case-control study was conducted. Cervical scrapings from patients with ASCUS or ASC-H were used for the quantitative methylation analysis of PAX1 methylation by MethyLight and HPV testing by HC2. Patients with ASC-H or ASCUS with repeated abnormal smears underwent colposcopic biopsy and subsequent therapies. Diagnoses were made by histopathology at a follow-up of 2 years. The efficacies of detecting high-grade lesions were compared. Fifty-eight cervical scrapings with cytological diagnosis of ASCUS (n = 41) and ASC-H (n = 17) were analyzed. One of the 41 (2.4%) ASCUS patients and seven of 17 (41.2%) ASC-H patients were confirmed to have HSIL. After dichotomy of the PMR, PAX1 methylation rates were significantly higher in ASC developing HSIL compared with those developing reactive atypia (87.5% vs. 12.5%, P < 0.001). Testing PAX1 methylation in cervical swabs of patients with ASC confers better sensitivity (87.5% vs. 62.5%) and specificity (98.0% vs. 86.0%) than HC2 HPV testing. We show for the first time that PAX1 hypermethylation analysis may be a better choice than HC2 in the triage of ASCUS and ASC-H.

The evaluation of p16INK4a immunoexpression/immunostaining and human papillomavirus DNA test in cervical liquid-based cytological samples

AIM

To evaluate the role of p16INK4a immunoexpression and human papillomavirus (HPV) DNA test for the detection of dyskaryotic cells in high-risk women.

MATERIALS AND METHODS

This work was a retrospective diagnostic study conducted in the University Hospital of Thessaloniki from January to December 2008. The subjects were women with current or previous HPV infection and current or previous cervical intraepithelial lesion (with or without treatment) or clinical warts. All liquid-based cytological samples were tested for P16INKa and HPV DNA test. The accuracy parameters used for the outcome included sensitivity, specificity, and positive predictive value.

RESULTS

A total of 226 women were included; the mean age was 29 years. Expression of p16INK4a was detected in the cytological samples of 13% of the negative cases, 44% of the cases of atypical squamous cells of undetermined significance, 46% of the cases of low-grade squamous intraepithelial lesion, and 78% of the cases of high-grade squamous intraepithelial lesion. A total of 91 women tested positive for high-risk HPV infection, and 54 of those had p16INK4a-positive staining reaction cells. The concordance between the 2 tests, HPV DNA and p16, was 59% regarding infection-positive cases. Diffuse strong parabasal p16INK4a immunostaining (nuclear score >2) was observed in 17 cases of the abnormal cytological findings (atypical squamous cells of undetermined significance, 2 cases; low-grade squamous intraepithelial lesion, 8 cases; high-grade squamous intraepithelial lesion, 7 cases). Colposcopy-directed biopsies were used as the criterion standard for the detection of cervical intraepithelial neoplasia in 91 women. The sensitivity of p16INK4a was 95% and the specificity was 92%, whereas the sensitivity of high-risk HPV was 100% and the specificity was 78%. The positive predictive value of p16INK4a was 71%, whereas that of HPV DNA was 44%.

CONCLUSION

The findings suggest that p16INK4a immunostaining can improve the accuracy of cytological examination and HPV DNA test and may be particularly useful in the triage of low-grade lesions.

Clinical, colposcopic and pathological characteristics of cervical and vaginal high-grade lesions negative for HPV by Hybrid Capture 2

OBJECTIVE

Less than 5% of women with cervical or vaginal biopsy proven high-grade squamous intraepithelial lesions (HG-SIL) show a negative Hybrid Capture 2 (HC2) result. We analyzed 1) human papillomavirus (HPV) genotypes by PCR in order to determine whether these cases represent infections by common or unusual types, and 2) the clinical, colposcopic and pathological differential characteristics of these patients.

METHODS

646 women with a histological diagnosis of HG-SIL and a HC2 test collected within 6 months prior to the diagnosis were identified. Patients with a negative HC2 result were selected. HPV was typed in the biopsy specimen in all by PCR using SPF10 and GP5+/6+ primers, and p16(INK4a) immunostaining was performed. The clinical and colposcopy findings of these women were compared with a control group of HG-SIL with positive HC2 result.

RESULTS

20 women (3.1%) with HG-SIL had a negative HC2. All biopsies were positive for p16(INK4). PCR analysis detected HPV types included in HC2 test in 55% of the cases, with an identical percentage of common viruses between women with relative light unit values above or below 0.40 (p=.361). False negative HC2 tests increased with age (p=.002) and were more frequent in patients with non satisfactory colposcopy or small sized lesions (p<.001).

CONCLUSION

A negative HC2 test is an infrequent event in women with HG-SIL. Common HPV types are identified in over half of the cases. Older women and patients with small lesions or non satisfactory colposcopy have a higher rate of HC2 negative results.

p16(INK4a) is superior to high-risk human papillomavirus testing in cervical cytology for the prediction of underlying high-grade dysplasia

BACKGROUND

The primary goal of this study was to compare the clinical performance of an optimized and rigorously controlled immunocytochemical (ICC) assay for p16(INK4a) to high-risk (HR) human papillomavirus (HPV) detection by polymerase chain reaction (PCR) as diagnostic adjuncts for cytology specimens from colposcopy patients.

METHODS

: The study included 403 cervical cytology specimens collected within 3 months of colposcopy. The colposcopic impression and cervical biopsy diagnosis served as the standards for correlation with cytological, p16(INK4a), and HPV data. p16(INK4a) was evaluated using an immunoperoxidase-based assay that was linear over 4 logs for the detection of HeLa-spiked positive control cytology specimens, using a threshold for positive test results that was based on receiver operating characteristic curve analysis. HR-HPV was detected by multiplex PCR using genotype-specific primers.

RESULTS

: In all combined diagnostic categories (negative for intraepithelial lesion and malignancy, atypical glandular cells, atypical squamous cells of undetermined significance, atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion, low-grade squamous intraepithelial lesion, and high-grade squamous intraepithelial lesion), the p16(INK4a) ICC and HR-HPV assays, respectively, had sensitivity of 81.7% and 83.3% (P = .81) and specificity of 78.1% and 50.9% (P < .001) for the detection of underlying > or =grade 2 cervical intraepithelial neoplasia (CIN) lesions on biopsy. Furthermore, the positive predictive value of p16(INK4a) ICC was greater than that of HR-HPV for patients with biopsies > or =CIN-2 (41.2% and 24.2%, respectively, P = .001).

CONCLUSIONS

: This p16(INK4a) immunocytochemical assay has superior specificity but similar sensitivity to HR-HPV testing to predict underlying high-grade dysplastic lesions in patients who are referred for colposcopy. The determination of the overall performance characteristics of p16(INK4a) immunocytochemistry, as an independent test or in combination with HPV testing in low-risk screening populations, however, will require subsequent large-scale prospective clinical trials.

The use of p16(INK4A) immunocytochemistry in "Atypical squamous cells which cannot exclude HSIL" compared with "Atypical squamous cells of undetermined significance" in liquid-based cervical smears

Even though p16(INK4a) (p16) immunocytochemistry has proven a useful accessory tool verifying the identification of atypical squamous cells of undetermined significance (ASC-US) categorized smears, the procedure still has limitations. To date few studies examining the usefulness of p16 immunocytochemistry in atypical squamous cells which cannot exclude HSIL (ASC-H), compared with ASC-US in liquid-based cervical smears. Therefore, we examined the correlation of p16 immunocytochemical staining with follow-up biopsy results on ASC-H categorized smears and compared the data with those classified as ASC-US on 105 liquid-based cytology samples. We found no statistical significance in the p16 expression of ASC-US smears and the presence of squamous intraepithelial lesions (SIL) in follow-up biopsies (p = 0.546). However, p16 expression did significantly correlate with the presence of SIL (p = 0.002) in ASC-H smears. There was a statistically significant relationship between p16 expression and presence of high grade squamous intraepithelial lesions (HSIL) or more on the follow-up biopsies in both ASC-US (p = 0.012) and ASC-H (p < 0.001) categorized smears. In ASC-US categorized smears, there was no statistical significance between p16 expression and the HR-HPV viral load (p = 0.091). But there was a statistical significance between p16 expression and the HR-HPV viral load (p < 0.001) in ASC-H categorized smears. Our results indicate that p16 immunostaining is a much better useful marker for HR-HPV infection and detection of SIL in ASC-H categorized smears compared to those defined as ASC-US.

[Human papillomaviruses in the pathogenesis of intraepithelial neoplasia (AIN) and carcinoma of the anus]

HPV infections have been implicated in the pathogenesis of anal cancers. The mode of infection and subsequent transformation resembles very much the pathogenesis of cervical and other HPV-associated cancers. The molecular dissection of individual steps required to achieve cellular transformation within an HPV-infected cell led to the identification of novel biomarkers that make it possible to identify HPV-transformed cells with substantially higher precision in comparison to conventional methods. Since effective antiretroviral therapy allows for possible long-term survival of HIV-infected individuals who are at very high risk to develop HPV-associated cancers in the anogenital tract, these new developments have become increasingly relevant for practicing dermatologists and proctologists. We here briefly review the basic concepts and some clinical applications of this recent research.

p16(INK4a) immunostaining in cytological and histological specimens from the uterine cervix: a systematic review and meta-analysis

BACKGROUND

P16(INK4a) is a biomarker for transforming HPV infections that could act as an adjunct to current cytological and histological assessment of cervical smears and biopsies, allowing the identification of those women with ambiguous results that require referral to colposcopy and potentially treatment.

MATERIAL AND METHODS

We conducted a systematic review of all studies that evaluated the use of p16(INK4a) in cytological or histological specimens from the uterine cervix. We also estimated the mean proportion of samples that were positive for p16(INK4a) in cytology and histology, stratified by the grade of the lesion.

RESULTS

Sixty-one studies were included. The proportion of cervical smears overexpressing p16(INK4a) increased with the severity of cytological abnormality. Among normal smears, only 12% (95% CI: 7-17%) were positive for the biomarker compared to 45% of ASCUS and LSIL (95% CI: 35-54% and 37-57%, respectively) and 89% of HSIL smears (95% CI: 84-95%). Similarly, in histology only 2% of normal biopsies (95% CI: 0.4-30%) and 38% of CIN1 (95% CI: 23-53%) showed diffuse staining for p16(INK4a) compared to 68% of CIN2 (95% CI: 44-92%) and 82% of CIN3 (95% CI: 72-92%).

CONCLUSION

Although there is good evidence that p16(INK4a) immunostaining correlates with the severity of cytological/histological abnormalities, the reproducibility is limited due to insufficiently standardized interpretation of the immunostaining. Therefore, a consensus needs to be reached regarding the evaluation of p16(INK4a) staining and the biomarker needs to be assessed in various clinical settings addressing specific clinical questions.

Triage of women with equivocal or low-grade cervical cytology results: a meta-analysis of the HPV test positivity rate

Consistent evidence underlines the utility of human papillomavirus (HPV) DNA testing in the management of women with equivocal cervical cytological abnormalities, but not in case of low-grade lesions. We performed a meta-analysis including studies where the high-risk probe of the Hybrid Capture-II is used to triage these two cytological categories. The triage test-positivity rate reflects the colposcopy referral workload.Data were pooled on the HPV test positivity rate in women with atypical squamous cells of undetermined significance (ASCUS/ASC-US) or low-grade squamous intraepithelial lesions (LSIL), derived from different cytological classification systems. The meta-analysis was restricted to studies, published between 1991 and 2007. A random-effect model was applied for meta-analytical pooling and the influence of covariates on the HPV positivity rate was analyzed by meta-regression. The variation by age was assessed within individual studies since age strata were not defined uniformly. On an average, 43% (95% CI: 40–46%) of women with ASCUS/ASC-US were high-risk HPV positive (range 23–74%). In women with LSIL, the pooled positivity rate was 76% (95% CI: 71–81%; range 55–89%). In spite of considerable inter-study heterogeneity, the difference in HPV positivity between the two triage groups was large and highly significant: 32% (95% CI: 27–38%). HPV rates dropped tremendously as age and cutoffs of test positivity increased. Other factors (cytological classification system, country, continent, collection method and year of publication) had no statistically significant impact, except in LSIL triage where HPV positivity was significantly lower in European compared to American studies. Women with LSIL, especially younger women, have high HPV positivity rates suggesting limited utility of reflex HPV triaging these cases. Research is needed to identify more specific methods to triage women with low-grade squamous cervical lesions.

Human papillomavirus mRNA and p16 detection as biomarkers for the improved diagnosis of cervical neoplasia

Human papillomavirus (HPV) infection of the genital tract is very common and normally follows a benign clinical course; however, in an unfortunate minority of infected individuals, it can cause disease that sometimes leads to cancer. It is accepted that HPV DNA testing has a role in the management of cervical disease both in a prevaccination and postvaccination era; however, to improve the specificity of this approach, there is a requirement to develop and validate tools/assays that can identify women at risk for progressive disease. There is evidence to suggest that detection of viral gene expression both directly and indirectly may constitute a more specific approach for delineating clinically significant infection compared with HPV DNA-based assays. HPV oncogene expression and evidence of its deregulation can be monitored through direct detection of viral mRNA transcripts or through detection of the cellular protein p16. For both approaches, commercial assays have been introduced and numerous studies have been conducted. The present article describes the scientific theory underpinning these approaches, their amenability to routine-diagnostic specimens/settings, and the clinical data that has been garnered through their application thus far. Currently, there is promising data indicating that HPV mRNA and p16 might play an important role in future cervical cancer screening scenarios. Still, large randomized studies are necessary to confirm the preliminary data.

METHODS

PubMed and OVID were interrogated with search terms "HPV RNA;" "HPV mRNA;" "HPV transcript-detection, testing, and methods;" "p16" AND "cervical cancer;" "p16" AND "CIN;" "p16" AND "histology"; "p16" AND "cytology;" "p16;" and "screening."

Immunocytochemical staining of p16(ink4a) protein as an adjunct test in equivocal liquid-based cytology

For cervical cancer screening, HPV-DNA test is expensive and is not easily available in all clinical situations. Thus, we investigated the role of p16(ink4a) immunostaining as another adjunct test to diagnose cervical neoplasia in equivocal liquid based cytology. Eighty-seven patients were randomly selected for this study (3 patients with normal, 84 patients with abnormal including 24 ASCUS, 30 LSIL, and 30 HSIL). We performed p16(ink4a) immunostaining on ThinPrep slide and on each case from the corresponding cervical biopsy tissues. High-risk HPV-DNA testing was also performed on all the subjects. We found that the immunoreactivity of p16(ink4a) is strongly correlated with the grade of cytologic and histologic diagnoses as well as with Hybrid Capture 2. In comparing the p16(ink4a) immunostaining with the Hybrid Capture 2 for accuracy of the diagnosis of CIN II/III or a higher-grade disease in the case of ASCUS/LSIL on ThinPrep, no significant differences were observed. Our data implies that p16(ink4a) immunocytochemical staining in liquid-based cytology specimens might be used as a good adjunct test to predict cervical histology in equivocal ThinPrep tests.

Evaluation of p16INK4a as a diagnostic tool in the triage of Pap smears demonstrating atypical squamous cells of undetermined significance

BACKGROUND

P16(INK4a) (p16) has emerged as a biomarker for the detection of high-risk human papillomavirus (HR-HPV) in Papanicolaou (Pap) smears. Many studies have confirmed a strong correlation between p16 immunohistochemical positivity and high-grade squamous intraepithelial lesions (HSIL) of the cervix. Because p16 is predictive of HR-HPV and HSIL, it seems plausible that p16 could be used as a diagnostic tool to triage atypical squamous cells of undetermined significance (ASCUS) Pap smears. In this way, Pap smears with no p16 staining could be recategorized as negative for intraepithelial lesion or malignancy (NILM) before final case disposition, thus preventing unnecessary and costly follow-up.

METHODS

p16 immunostains were performed on 178 ThinPrep (Cytyc, Marlborough, Mass) Pap smears signed out as ASCUS among 5 cytopathologists. p16 stains were independently scored between 0 (no staining) and 4 (staining in cells with nuclear aberration) by either 2 or 3 pathologists. The p16 score was compared with both Hybrid Capture 2 (hc(2)) (Digene, Gaithersburg, Md) and follow-up (Pap smear and tissue) results.

RESULTS

The sensitivity and specificity of p16 immunohistochemistry compared with both hc(2) and follow-up were not statistically significant, with both data subsets having P-values greater than .05.

CONCLUSIONS

Statistical significance was not demonstrated in any of the data subsets, indicating that the p16 score alone cannot be used to recategorize Pap smears from ASCUS to NILM as a means to prevent unnecessary and expensive follow-up. Although not meeting criteria for statistical significance, the sensitivity and positive predictive value of p16 scores versus tissue follow-up only were more statistically favorable, suggesting that p16 has better correlation with tissue follow-up than results of hc(2). In addition, p16 staining was identified consistently in atrophic Pap smears, including 23 of 25 additional NILM atrophic smears stained, indicating that p16 cannot be used as a marker to triage atypical atrophic smears.

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.

[The p16INK4a protein: a cytological marker for detecting high grade intraepithelial neoplasia of the uterine cervix]

The identification of a small percentage of high grade cervical intraepithelial neoplasia (HGCIN) among patients with a diagnosis of atypical squamous cells of undetermined significance (ASC-US) and low grade squamous intraepithelial lesion (LSIL) is one of the difficulties in cytology based cervical cancer screening. p16INK4a is a surrogate marker for the initiation of HPV mediated cervical carcinogenesis. This article describes the detection of the protein p16INK4a by immunocytochemistry coupled with the use of a nuclear score to differentiate abnormal basal cells from metaplastic or atrophic cells. The results of a pilot series of 210 liquid based cytology (LBC) specimens of which 108 were considered normal, 52 with a diagnosis of LSIL and 50 with a diagnosis of high grade SIL are described. The second series includes 137 LBC specimens with an ASC-US diagnosis and 88 with a LSIL diagnosis with an histological correlation. The overall sensitivity for the diagnosis of HGCIN using for the labeled squamous cells a nuclear score superior to 2 was 96% and the specificity was 83%. The sensitivity in the ASC-US was 95% and the specificity was 84%, in the LSIL group 100% and 81%, respectively. These data suggest to study a large series of LBC smears with a diagnosis of ASC-US and LSIL to confirm its efficacy of predicting the presence of an HGCIN.

Human papillomavirus testing and molecular markers of cervical dysplasia and carcinoma

Cervical cancer is the second most common cancer in women worldwide. Human papillomavirus (HPV) is the etiologic agent for the vast majority of premalignant and malignant lesions, and high-risk HPV types can be detected in almost all cases of cervical dysplasia and carcinoma. HPV testing has been widely adopted for the triage of patients after a cervical cytology screening test (Papanicolaou smear or liquid-based cervical cytology such as ThinPrep or SurePath) interpretation of atypical squamous cells of undetermined significance (ASCUS), and HPV testing is increasingly used for screening in conjunction with cervical cytology. Although cervical cytology is a highly effective screening test for cancer, it has limited specificity for clinically significant lesions in cases with low-grade cytologic abnormalities. Up to a quarter of all patients may have a false-negative result on the basis of cervical cytology testing alone. This review focuses on HPV testing methods and molecular markers and their clinical relevance. HPV testing and surrogate molecular markers of HPV infection (p16INK4a) may help identify cases that are associated with underlying high-grade premalignant or malignant lesions and may also reduce aggressive treatment of patients with low-grade lesions.

Triage of women with ASCUS and LSIL cytology: use of qualitative assessment of p16INK4a positive cells to identify patients with high-grade cervical intraepithelial neoplasia

BACKGROUND

The identification of a small percentage of high-grade cervical intraepithelial neoplasias (HGCIN) among patients with minor cytological abnormalities (atypical squamous cells of undetermined significance [ASCUS] and/or low-grade squamous intraepithelial lesions [LSIL] group) is a major problem in cytology-based cervical cancer screening. The authors investigated the efficacy of p16INK4a as a biomarker to identify samples of patients with HGCIN among those with an ASCUS or LSIL result in Papanicolaou cytology.

METHODS

Consecutive liquid-based cytology specimens of 137 ASCUS and 88 LSIL results were selected from gynecologists who adopted a triage regimen with biopsy under colposcopy 2 months later, independent of the p16INK4a result. p16INK4a stained slides were prepared and independently read by 2 observers, who used a recently described score to categorize p16INK4a stained squamous cells. The endpoint of the study was detection of a biopsy-confirmed HGCIN.

RESULTS

The overall sensitivity and specificity of p16INK4a positive cells with a nuclear score >2 for diagnosis of HGCIN in ASCUS and LSIL cases combined was 96% and 83%, respectively. The sensitivity and specificity in the ASCUS group was 95% and 84%, and 100% and 81% in the LSIL group, respectively. Two observers had a high concordance in assessing p16INK4a stained cells (kappa value of 0.841).

CONCLUSIONS

These data suggested that the use of p16INK4a as a biomarker combined with nuclear scoring of p16INK4a positive cells in cervical cytology to triage ASCUS and/or LSIL cases allows identification of HGCIN with good sensitivity and specificity.