p16iNK4a as a complementary marker of high-grade intraepithelial lesions of the uterine cervix. I: Experience with squamous lesions in 189 consecutive cervical biopsies

An Emerging Anti-p16 Antibody-BC42 Clone as an Alternative to the Current E6H4 for Use in the Female Genital Tract Pathological Diagnosis: Our Experience and a Review on p16ink4a Functional Significance, Role in Daily-Practice Diagnosis, Prognostic Potential, and Technical Pitfalls

Background: To date, useful diagnostic applications of p16 IHC have been documented in gynecological pathology both for HPV-related and non-HPV-related lesions. In the present article, we reported our experience with the novel anti-p16 INK4a antibody (clone BC42), whose expression was tested across all different gynecologic neoplasms; we also compared it to the traditional E6H4 clone. Moreover, we discussed and explored all the diagnostic applications of p16 IHC in gynecologic pathology. Methods: Consultation cases covering a 5-year period (2016–2020) regarding gynecological neoplastic and non-neoplastic lesions in which immunohistochemistry for p16, clone E6H4 was originally performed, were retrospectively retrieved from the files of our institution. Immunohistochemical staining for p16ink4a (BC42) [Biocare Medical group-Paceco USA; Bioptica Milan] and p16ink4a (E6H4) [Ventana Medical Systems-Arizona USA; Roche] was performed by using the Ventana automated immunostainer (Ventana Medical Systems, Tucson, AZ, USA). The immunostaining pattern was defined as negative, focal/patchy, or diffuse. Results: A total of 196 cases, represented by 36 high-grade SIL/CIN3 of the uterine cervix, 30 cervical adenocarcinomas, 22 cervical squamous cell carcinoma, 70 endometrial carcinomas, 25 high grade serous ovarian carcinomas, 6 uterine adenomatoid tumors, and 10 uterine leiomyosarcomas were included in this study. Results showed concordant staining quality of both clones on all tested neoplastic tissues. Conclusions: The novel anti-p16 antibody (BC42 clone) appeared as an alternative to the current E6H4 for use in gynecological neoplasms, offering similar levels of positivity and equally reliable staining results.

The Stem Cell-associated Transcription Factor SOX2 as a Diagnostic Marker of High-grade Squamous Intraepithelial Lesion of the Uterine Cervix in Comparison With p16 and Ki-67

The transcription factor SOX2 has been identified as an oncogene involved in the pathogenesis of squamous cell carcinoma (SCC) of multiple sites, including the uterine cervix. The relationship between SOX2 overexpression and the continuum of precancerous lesions of the cervix has not been previously elucidated. We evaluated SOX2 immunohistochemical expression in normal cervix, low-grade squamous intraepithelial lesion (LSIL) (mild squamous dysplasia), high-grade squamous intraepithelial lesion (HSIL) (moderate and severe dysplasia) and SCC of the cervix in comparison with p16 and Ki-67. Staining patterns were scored as negative, basal one third of the epithelium, lower two third, or full thickness. The results showed that SOX2 expression was limited to the basal one third in 84% of LSIL cases, whereas 95% of HSIL showed SOX2 expression up to two third or full thickness (P<0.0001). p16 and Ki-67 displayed similar results. The difference in SOX2 expression between moderate and severe dysplasia was not statistically significant (P=0.53). Invasive SCC positivity was as follows: SOX2 94%; p16 89%; and Ki-67 100%. Our findings support a role for SOX2 in the progression of squamous dysplasia to SCC. The Lower Anogenital Standardization Terminology Project's recent assertion of a lack of a biological correlate to cervical intraepithelial neoplasia II is also upheld by SOX2. For equivocal situations in which a diagnosis of cervical intraepithelial neoplasia II would have been made, Lower Anogenital Standardization Terminology recommends p16, or other biomarkers such as Ki-67 to clarify the diagnosis. SOX2, with a clean nuclear staining pattern, may also be suitable for this role.

Risk Categorization with Different Grades of Cervical Pre-Neoplastic Lesions - High Risk HPV Associations and Expression of p53 and RARβ

Objective:

To identify high risk HPV associations by evaluating linked p16 overexpression and also the expression of p53 and RARβ together with histopathology for risk categorization of cervical pre-neoplastic lesions.

Materials and Methods:

Immunohistochemical staining was performed on 100 cases of cervical pre- neoplastic lesions for expression of biomarkers like p16, p53 and RARβ for comparison with haematoxylin/eosin (HE) findings. All the experimentally generated data were statistically analyzed.

Results:

In this study 70% cases showed overexpression of p16INK4A increasing progressively from CIN I to CIN II but reduced in CIN III (p <0.01). p53 oncoprotein expression was seen in 51% cases, again with increments from CIN I to CIN II with slight reduction in CIN III (p<0.01). Some 24% cases showed negative immunoreactivity for the putative tumor suppressor gene RARβ (p>0.05).

Conclusion:

Our study provides support for the idea that p16 can be used to identify associations with HPV , as well as having potential along with p53 and RARβ for categorizing cervical pre-neoplastic cases having a higher risk of neoplastic conversion. Thus it may be concluded that accurate risk categorization can be achieved with the help of genetic markers as well as histopathology.

Expression pattern of p53-binding protein 1 as a new molecular indicator of genomic instability in bladder urothelial carcinoma

Copy number alterations and loss of heterozygosity are associated with increasing tumor grade and bladder cancer stage. Our previous study suggested that co-expression of Ki-67 and p53-binding protein 1 (53BP1) could provide an indicator of an abnormal DNA damage response (DDR) pathway. The present study investigated 53BP1 expression as a novel molecular marker in urothelial carcinoma (UC) using bladder tissues with in total of 40 cases including a normal urothelium, urothelial papilloma, low-grade UC, or high-grade UC. Double-label immunofluorescence was used to analyze 53BP1 and Ki-67 expression. This was compared with the level of chromosomal instability and with the expression of other DDR molecules catalytic subunit. This study identified clear differences in the 53BP1 expression patterns in urothelial carcinogenesis, and their close association with genomic instability. 53BP1 abnormal immunoreactivity, particularly with co-localization of Ki-67, was restricted to malignant tissues. Our analyses indicated that a cut-off of >4% of nuclei with 53BP1 abnormal expression plus Ki-67 immunoreactivity distinguished high-grade UC from low-grade UC with 80.0% sensitivity and 100% specificity. We therefore propose that double immunofluorescent analysis of 53BP1 and Ki-67 expression could provide a useful tool to estimate the chromosomal instability and malignant potential of urothelial tumors.

Three-tiered score for Ki-67 and p16ink4a improves accuracy and reproducibility of grading CIN lesions

Aims

To investigate the accuracy and reproducibility of a scoring system for cervical intraepithelial neoplasia (CIN1–3) based on immunohistochemical (IHC) biomarkers Ki-67 and p16^ink4a.

Methods

115 cervical tissue specimens were reviewed by three expert gynaecopathologists and graded according to three strategies: (1) CIN grade based on H&E staining only; (2) immunoscore based on the cumulative score of Ki-67 and p16^ink4a only (0–6); and (3) CIN grade based on H&E supported by non-objectified IHC 2 weeks after scoring 1 and 2. The majority consensus diagnosis of the CIN grade based on H&E supported by IHC was used as the Reference Standard. The proportion of test positives (accuracy) and the absolute agreements across pathologists (reproducibility) of the three grading strategies within each Reference Standard category were calculated.

Results

We found that immunoscoring with positivity definition 6 yielded the highest proportion of test positives for Reference Standard CIN3 (95.5%), in combination with the lowest proportion of test positives in samples with CIN1 (1.8%). The proportion of test positives for CIN3 was significantly lower for sole H&E staining (81.8%) or combined H&E and IHC grading (84.8%) with positivity definition ≥CIN3. Immunoscore 6 also yielded high absolute agreements for CIN3 and CIN1, but the absolute agreement was low for CIN2.

Conclusions

The higher accuracy and reproducibility of the immunoscore opens the possibility of a more standardised and reproducible definition of CIN grade than conventional pathology practice, allowing a more accurate comparison of CIN-based management strategies and evaluation of new biomarkers to improve the understanding of progression of precancer from human papillomavirus infection to cancer.

Concomitant use of heat-shock protein 70, glutamine synthetase and glypican-3 is useful in diagnosis of HBV-related hepatocellular carcinoma with higher specificity and sensitivity

Hepatocellular carcinoma is the third leading cause of cancer-related death worldwide and late diagnosis is the main cause of death in HCC patients. In this study expression patterns of HSP70, GPC3 and GS and their relationships with pathogenesis of HCC in Iranian patients were investigated. The expression of HSP70, GPC3 and GS were determined by immunohistochemistry and quantitative real-time PCR (q-PCR) methods, using 121 cases from patients with HBV alone, HCC without HBV, HBV+HCC and 30 normal tissues as control group. HSP70, GPC3 and GS were expressed in higher levels in HBV-related HCC samples compared to HBV alone group. The results showed that the labeling index of HSP70, GPC3 and GS are correlated with immunohistochemical and molecular expressions of HSP70, GPC3 and GS. The sensitivity and specificity for HCC diagnosis were 43.4% and 89.7% for HSP70, 64.3% and 90.4% for GPC3, and 60.7% and 94.3% for GS, respectively. The sensitivity and specificity of the panels with 3, 2 and 1 positive markers, regardless of which one, were 21.6% and 100%, 51.3% and 100% and 93.4% and 80.5% respectively. The current study demonstrated an association between HSP70, GPC3 and GS expressions and HBV-related HCC in our population. It was concluded that HSP70, GPC3 and GS expressions could be useful biomarkers for increasing the specificity and sensitivity of HCC diagnosis to acceptable level. Also, proper combinations of these 3 markers could improve diagnostic accuracy.

Cervical intraepithelial neoplasia in pregnancy: Interference of pregnancy status with p16 and Ki-67 protein expression

To date, there are evidence-based guidelines available for cervical dysplasia diagnosed in pregnancy. Certain functional biomarkers have proven useful in the prediction of regressing and non-regressing cervical intraepithelial neoplasia (CIN) lesions in non-pregnant women. In the present study, Ki-67 and p16 immunostaining were evaluated in different grades of CIN lesions diagnosed in pregnant or non-pregnant women with the aim to identify any differences in order to better understand the behavior of CIN in pregnancy. The current retrospective case-control study included 17 pregnant patients that conceived naturally with first-time onset of CIN occurring at no later than 16 gestational weeks. The control group included 17 non-pregnant patients matched for age, parity and number of previous sexual partners. Exclusion criteria included previous cervical treatment, immunocompromised status, chronic hepatitis B and/or C and cigarette smoking. p16 and Ki-67 protein expression were respectively detected using the CINtec Histology kit and monoclonal antibodies against Ki-67. p16 and Ki-67 staining were analyzed using a classification system based on the distribution of positivity on a semi-quantitative three point-scale. p16 and Ki-67 immune reactivity correlated positively with the grade of epithelial dysplasia in the total cohort of pregnant and non-pregnant patients; expression increased linearly from CIN1 to CIN3. Furthermore, the association between p16 immunostaining and CIN grade was significant in non-pregnant patients but not in pregnant patients. In pregnant patients, positivity for Ki-67 was less intense than in non-pregnant patients. These results appear to suggest that pregnancy status interferes with the expression of cellular proteins involved in cell-cycle regulation and the carcinogenic process induced by high-risk human papilloma virus, exhibiting increased variability in their staining.

Expression of Sialyl Lewis a, Sialyl Lewis x, Lewis y, Gal-3, Gal-7, STMN1 and p16 in cervical dysplasia

AIM

Cervical intraepithelial neoplasia (CIN) is commonly divided into three grades. Guidelines increasingly recommend surgery only in CIN 3 lesions. We investigated markers to evaluate differences in CIN 2 and 3 lesions as well as possible predictors for regression/progression in CIN 2 lesions.

MATERIALS & METHODS

Biopsies (n = 128) of healthy cervical tissue and CIN 1-3 were stained for Sialyl Lewis a, Sialyl Lewis x, Lewis y, Gal-3, Gal-7, STMN1 and p16.

RESULTS

We observed significant differences between CIN 2 and 3 lesions for Sialyl Lewis a, Sialyl Lewis x, Gal-3, Gal-7, STMN1 and p16. Expression of Sialyl Lewis a was significantly higher in CIN 2 patients who progressed during follow-up.

CONCLUSION

Significant differences in marker expression support the differentiation of CIN 2 and 3. Lewis a may help to predict progression/regression in CIN 2 patients.

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.

Assessment of correlation between p16INK4a staining, specific subtype of human papillomavirus, and progression of LSIL/CIN1 lesions: first comparative study

OBJECTIVES

To study and compare the effectiveness of p16(INK4a) staining and specific human papillomavirus (HPV) subtypes as a prognostic marker in cervical intraepithelial neoplasia grade 1 (CIN1; low-grade squamous intraepithelial lesions).

METHODS

Sixty-four cervical samples diagnosed as CIN1 and stained with p16(INK4a), with HPV status assessed by polymerase chain reaction-direct sequencing.

RESULTS

Of the 34 p16(INK4a)-negative biopsy specimens, 26 regressed, seven persisted, and one progressed. Of the 20 p16(INK4a) diffusely positive biopsy specimens, seven regressed, eight persisted, and five progressed. Ten biopsy specimens stained positive only in the lower one-third of the sample, of which seven regressed and three persisted. p16(INK4a) diffusely positive CIN1 lesions were associated with only high-risk HPV subtypes, with the exception of one HPV-negative biopsy specimen. Three different high-risk HPV subtypes and one low-risk HPV subtype (HPV66) were identified in the six CIN1 lesions that progressed.

CONCLUSIONS

There is a significant relationship between p16(INK4a) immunostaining and follow-up (P = .002). p16(INK4a)-negative specimens or positivity in the lower one-third of CIN1 lesions seldom progress to a CIN2-3 lesion.

Tumourigenesis driven by the human papillomavirus type 16 Asian-American e6 variant in a three-dimensional keratinocyte model

Infection with a transforming human papillomavirus (HPV) such as type 16 (of species Alphapapillomavirus 9) causes ano-genital and oral tumours via viral persistence in human squamous cell epithelia. Epidemiological studies showed that the naturally occurring HPV16 Asian-American (AA) variant (sublineage D2/D3) is found more often than the European Prototype (EP) (sublineage A1) in high-grade cervical neoplasia and tumours compared to non-cancer controls. Just three amino acid changes within the early gene, E6, of HPV16 AA have been linked to this augmented tumourigenicity. The AAE6 variant's greater immortalizing and transforming potential over EPE6 has recently been confirmed in retrovirally-transduced keratinocytes expressing the E6 gene only. However, the tumourigenic role of the full-length viral genome of HPV16 has not yet been addressed with regard to these E6 variants. To investigate this process in the context of these two HPV16 E6 genotypes, an organotypic tissue culture model was used to simulate the HPV infectious life cycle. The AAE6 variant demonstrated an enhanced ability over EPE6 to drive the viral life cycle toward tumourigenesis, as evidenced phenotypically—by a more severe grade of epithelial dysplasia with higher proliferation and deregulated differentiation, and molecularly—by high viral oncogene E6 and E7 expression, but lack of productive viral life cycle markers. In contrast, EPE6 had low E6 and E7 but high E1∧E4 expression, indicative of a productive life cycle. We suggest increased viral integration into the host genome for AAE6 as one possible mechanism for these observed differences from EPE6. Additionally, we found downstream effects on immortalization and host innate immune evasion. This study highlights how minor genomic variations in transforming viruses can have a significant affect on their tumourigenic ability.

Adjunct p16(INK4a) immunohistochemistry aids the detection of high-grade squamous intraepithelial lesions in endocervical curettage specimens

OBJECTIVES

We questioned whether the use of p16(INK4a) immunohistochemistry in endocervical curettage (ECC) specimens would improve the detection of high-grade squamous intraepithelial lesions (HSIL) in a high-risk patient population.

METHODS

Papanicolaou test results were retrieved in 58 consecutive ECC specimens that were previously diagnosed as no histopathologic abnormality in patients with antecedent HSIL or atypical squamous cells, cannot exclude HSIL. An H&E recut and immunohistochemistry for p16(INK4a) were performed on all cases.

RESULTS

HSIL were found in 18 (31%) ECC specimens originally interpreted as negative. Of these 18 cases, three had moderate-sized fragments of ectocervical epithelium with HSIL seen on the recut H&E with concurrent positivity for p16(INK4a). Fourteen cases had rare to occasional clusters of atypical cells with strong immunoreactivity for p16(INK4a). A single case showed a medium-sized fragment of HSIL on the p16(INK4a)-stained section.

CONCLUSIONS

The use of recuts and adjunct p16(INK4a) should be considered when evaluating ECC specimens in high-risk patient populations.

Ancillary Diagnostics in Gynecologic Cytology

Cytology has been the mainstay of cervical dysplasia and cancer screening in the United States. The specificity of a woman harboring a high-grade lesion when identified as high-grade squamous intraepithelial lesion on Pap test is high; however, the test suffers from low sensitivity. Epidemiology studies have demonstrated that human papillomavirus (HPV) types 16 and 18 account for most cervical squamous cell carcinomas. Tests have been developed to identify high-risk HPV, some specifically to identify HPV 16 and 18. Simultaneous to the increase in HPV detection methods, interdisciplinary groups are making recommendations on the managerial use of the tests.

Correlation of EGFR, pEGFR and p16INK4 expressions and high risk HPV infection in HIV/AIDS-related squamous cell carcinoma of conjunctiva

Background

Squamous cell carcinoma of conjunctiva has increased tenfold in the era of HIV/AIDS. The disease pattern has also changed in Africa, affecting young persons, with peak age-specific incidence of 30-39 years, similar to that of Kaposi sarcoma, a well known HIV/AIDS defining neoplasm. In addition, the disease has assumed more aggressive clinical course. The contributing role of exposure to high risk HPV in the development of SCCC is still emerging.

Objective

The present study aimed to investigate if immunohistochemical expressions of EGFR, pEGFR and p16, could predict infection with high risk HPV in HIV-related SCCC.

Methods

FFPE tissue blocks of fifty-eight cases diagnosed on hematoxylin and eosin with SCCC between 2005-2011, and subsequently confirmed from medical records to be HIV positive at the department of human pathology, UoN/KNH, were used for the study. Immunohistochemistry was performed to assess the expressions of p16INK4A, EGFR and pEGFR. This was followed with semi-nested PCR based detection and sequencing of HPV genotypes. The sequences were compared with the GenBank database, and data analyzed for significant statistical correlations using SPSS 16.0. Ethical approval to conduct the study was obtained from KNH-ERC.

Results

Out of the fifty-eight cases of SCCC analyzed, twenty-nine (50%) had well differentiated (grade 1), twenty one (36.2%) moderately differentiated (grade 2) while eight (13.8%) had poorly differentiated (grade 3) tumours. Immunohistochemistry assay was done in all the fifty eight studied cases, of which thirty nine cases (67.2%) were positive for p16INK4A staining, forty eight cases (82.8%) for EGFR and fifty one cases (87.9%) showed positivity for p-EGFR. HPV DNA was detected in 4 out of 40 SCCC cases (10%) in which PCR was performed, with HPV16 being the only HPV sub-type detected. Significant statistical association was found between HPV detection and p16INK4 (p=0.000, at 99% C.I) and EGFR (p=0.028, at 95% C.I) expressions, but not pEGFR. In addition, the expressions of these biomarkers did not show any significant association with tumor grades.

Conclusion

This study points to an association of high risk HPV with over expressions of p16INK4A and EGFR proteins in AIDS-associated SCCC.

Use of human papillomavirus DNA, E6/E7 mRNA, and p16 immunocytochemistry to detect and predict anal high-grade squamous intraepithelial lesions in HIV-positive and HIV-negative men who have sex with men

Background

Men who have sex with men (MSM) are at high risk of having anal cancer. Anal high-grade squamous intraepithelial lesion (HSIL) is the precursor of anal cancer. We explored the use of different biomarkers associated with human papillomavirus (HPV) infection and HPV-mediated cell transformation to detect and predict HSIL among HIV-positive and HIV-negative MSM.

Methodology/Principal Findings

A total of 123 HIV-positive and 123 HIV-negative MSM were enrolled and followed for 12 months. High-resolution anoscopy (HRA) with biopsies were performed at every visit along with anal sample collection for cytology, high-risk HPV DNA genotyping, HPV E6/E7 mRNA, and p16 immunocytochemistry. Performance characteristics and area under the receiver operator characteristics curve were calculated for these biomarkers at baseline, and Cox regression compared the usefulness of these biomarkers in predicting incident HSIL. High-risk HPV DNA, E6/E7 mRNA, and p16 immunocytochemistry each identified 43–46% of MSM whose baseline test positivity would trigger HRA referral. E6/E7 mRNA had the highest sensitivity (64.7%) and correctly classified the highest number of prevalent HSIL cases. With the exception of p16 immunochemistry, most tests showed significant increases in sensitivity but decreases specificity versus anal cytology, while the overall number of correctly classified cases was not significantly different. Baseline or persistent type 16 and/or 18 HPV DNA was the only test significantly predicting incident histologic HSIL within 12 months in models adjusted for HIV status and low-grade squamous intraepithelial lesions at baseline.

Conclusions/Significance

Countries with a high HIV prevalence among MSM and limited HRA resources may consider using biomarkers to identify individuals at high risk of HSIL. E6/E7 mRNA had the highest sensitivity for prevalent HSIL detection regardless of HIV status, whereas type 16 and/or 18 HPV DNA performed best in predicting development of incident HSIL within 12 months.

Gene expression profile regulated by the HPV16 E7 oncoprotein and estradiol in cervical tissue

The HPV16 E7 oncoprotein and 17β-estradiol are important factors for the induction of premalignant lesions and cervical cancer. The study of these factors is crucial for a better understanding of cervical tumorigenesis. Here, we assessed the global gene expression profiles induced by the HPV16 E7 oncoprotein and/or 17β-estradiol in cervical tissue of FvB and K14E7 transgenic mice. We found that the most dramatic changes in gene expression occurred in K14E7 and FvB groups treated with 17β-estradiol. A large number of differentially expressed genes involved in the immune response were observed in 17β-estradiol treated groups. The E7 oncoprotein mainly affected the expression of genes involved in cellular metabolism. Our microarray data also identified differentially expressed genes that have not previously been reported in cervical cancer. The identification of genes regulated by E7 and 17β-estradiol, provides the basis for further studies on their role in cervical carcinogenesis.

Role of p16, CK17, p63, and human papillomavirus in diagnosis of cervical intraepithelial neoplasia and distinction from its mimics

BACKGROUND

Diagnosis of cervical intraepithelial neoplasia (CIN), the precursor forms of cervical cancer, can be tricky and it has led to discrepancy between pathologists in distinguishing them from its mimics such as atypical immature metaplasia (AIM), immature squamous metaplasia (ISM), reactive atypia (RA), atrophy, and basal cell hyperplasia (BCH). To overcome this problem this study aims at using immunohistochemical (IHC) markers p16, p63, CK17, and human papillomavirus (HPV) to differentiate CIN from its mimics.

MATERIALS AND METHODS

This study analyzed 350 cervical samples with histomorphological diagnosis of CIN and its mimics and the utility of IHC markers p16, p63, CK17, and HPV in distinction was analyzed.

RESULTS

p16 showed 67.76% sensitivity and 99.4% specificity whereas HPV showed 57.9% sensitivity and 91.6% specificity in detecting CIN. CK17 and p63 did not show any significance in distinguishing CIN from its mimics. After IHC of AIM cases, 66.7% were reclassified as CIN III, 27.8% as ISM with reactive atypia (ISMRA), and 5.5% case as immature condyloma. In total, 3.7% of diagnosis was upgraded to CIN and 0.6% of pre-IHC diagnosis was downgraded from CIN to reactive lesions.

CONCLUSION

IHC panel comprising p16, p63, CK17, and HPV are useful adjuncts in distinguishing CIN from its mimics particularly when histomorphology has overlapping morphological features.

p16 is superior to ProEx C in identifying high-grade squamous intraepithelial lesions (HSIL) of the anal canal

Although the incidence of human papillomavirus (HPV)-associated anal neoplasia is increasing, interobserver and intraobserver reproducibility in the grading of biopsy specimens from this area remains unacceptably low. Attempts to produce a more reproducible grading scheme have led to the use of biomarkers for the detection of high-risk HPV (HR-HPV). We evaluated the performance of standard morphology and biomarkers p16, ProEx C, and Ki-67 in a set of 75 lesions [17 nondysplastic lesions, 23 low-grade squamous intraepithelial lesions (LSIL)/condyloma, 20 high-grade squamous intraepithelial lesions (HSIL), 15 invasive squamous cell carcinomas] from the anal and perianal region in 65 patients and correlated these findings with HPV subtype on the basis of a type-specific multiplex real-time polymerase chain reaction assay designed to detect HR-HPV. A subset of cases with amplifiable HPV DNA was also sequenced. HSIL was typically flat (15/20), and only a minority (4/20) had koilocytes. In contrast, only 1 LSIL was flat (1/23), and the remainder were exophytic. The majority of LSIL had areas of koilocytic change (20/23). HR-HPV DNA was detected in the majority (89%) of invasive carcinomas and HSIL biopsies, 86% and 97% of which were accurately labeled by strong and diffuse block-positive p16 and ProEx C, respectively. LSIL cases, however, only infrequently harbored HR-HPV (13%); most harbored low-risk HPV (LR-HPV) types 6 and 11. Within the LSIL group, p16 outperformed ProEx C, resulting in fewer false-positive cases (5% vs. 75%). Ki-67 was also increased in HR-HPV-positive lesions, although biopsies with increased inflammation and reactive changes also showed higher Ki-67 indices. These data suggest that strong and diffuse block-positive nuclear and cytoplasmic labeling with p16 is a highly specific biomarker for the presence of HR-HPV in anal biopsies and that this finding correlates with high-grade lesions.

The specificity and patterns of staining in human cells and tissues of p16INK4a antibodies demonstrate variant antigen binding

The validity of the identification and classification of human cancer using antibodies to detect biomarker proteins depends upon antibody specificity. Antibodies that bind to the tumour-suppressor protein p16INK4a are widely used for cancer diagnosis and research. In this study we examined the specificity of four commercially available anti-p16INK4a antibodies in four immunological applications. The antibodies H-156 and JC8 detected the same 16 kDa protein in western blot and immunoprecipitation tests, whereas the antibody F-12 did not detect any protein in western blot analysis or capture a protein that could be recognised by the H-156 antibody. In immunocytochemistry tests, the antibodies JC8 and H-156 detected a predominately cytoplasmic localised antigen, whose signal was depleted in p16INK4a siRNA experiments. F-12, in contrast, detected a predominately nuclear located antigen and there was no noticeable reduction in this signal after siRNA knockdown. Furthermore in immunohistochemistry tests, F-12 generated a different pattern of staining compared to the JC8 and E6H4 antibodies. These results demonstrate that three out of four commercially available p16INK4a antibodies are specific to, and indicate a mainly cytoplasmic localisation for, the p16INK4a protein. The F-12 antibody, which has been widely used in previous studies, gave different results to the other antibodies and did not demonstrate specificity to human p16INK4a. This work emphasizes the importance of the validation of commercial antibodies, aside to the previously reported use, for the full verification of immunoreaction specificity.

The Utility of p16INK4a and Ki-67 as a Conjunctive Tool in Uterine Cervical Lesions

Background

Immunohistochemical staining for p16INK4a and Ki-67 has been used to improve the accuracy in making a diagnosis of the uterine cervix cancer on biopsy. This study was conducted to examine the usefulness of these markers in the pathological diagnosis based on cervical biopsy.

Methods

We selected a consecutive series of 111 colposcopically directed cervical punch biopsies. Using these biopsy samples, we performed an immunohistochemical staining for p16INK4a and Ki-67 to establish a diagnosis. The slides were circulated among four pathologists in a sequential order: the hematoxylin and eosin (H&E) slide, H&E slide and p16INK4a-stained slide, and H&E slide, p16INK4a- and Ki-67-stained slides.

Results

The overall rates of the concordance in the first, the second, and the third diagnoses were 77.5%, 82.0%, and 82.0%, respectively. The rate of the concordance in the diagnosis of cervical intraepithelial neoplasm (CIN) 2/3 was increased from 62.2% to 73.0%. But there was a variability in the rate of the revision of the diagnosis between the pathologists. With the application of criteria for interpreting the expressions of p16INK4a and Ki-67, benign and CIN 1 lesions showed a p16INK4a expression score of 0 or 1. But CIN 2 and CIN 3 lesions showed a p16INK4a expression score of 2 and 3, respectively.

Conclusions

The immunostain for p16INK4a and Ki-67 might be useful in reducing an inter-observer variability. But criteria for interpreting both markers should be strictly applied.

Near-infrared Raman Microspectroscopy Detects High-risk Human Papillomaviruses

BACKGROUND

Detecting human papillomaviruses (HPVs) infection in cervical cells is an exceedingly important part of the clinical management of cervical dysplasia. Current guidelines in women's health outline the need for both the Papanicolaou test as well as high-risk HPV testing. Testing for HPV is expensive, is time-consuming, and requires experienced technicians.

METHODS

Two sets of near-infrared Raman microspectroscopy experiments were conducted using a Raman confocal microscope system. First, Raman spectra were acquired from four different cell culture lines, two positive for HPV (HeLa, SiHa), one negative for HPV, but malignant (C33A), and one normal, HPV-negative line (NHEK). The three malignant lines were all derived from cervical cells. Second, Raman spectra were acquired from deidentified patient samples that were previously tested for the presence of high-risk HPV.

RESULTS

The spectra from the cell culture lines and the patient samples contained many statistically significant differences. Using sparse multinomial logistic regression to classify the data led to classification accuracies of 89% to 97% for the cell culture samples and 98.5% for the patient samples.

CONCLUSIONS

Raman micro-spectroscopy can be used to detect HPV and differentiate among specific HPV strains. This technique may provide health providers with a new method for quickly testing cell samples for the presence of HPV.

Looking ahead: a case for human papillomavirus testing of self-sampled vaginal specimens as a cervical cancer screening strategy

Even in the era of highly effective human papillomavirus (HPV) prophylactic vaccines, substantial reduction in worldwide cervical cancer mortality will only be realized if effective early detection and treatment of the millions of women already infected and the millions who may not receive vaccination in the next decade can be broadly implemented through sustainable cervical cancer screening programs. Effective programs must meet three targets: (i) at least 70% of the targeted population should be screened at least once in a lifetime, (ii) screening assays and diagnostic tests must be reproducible and sufficiently sensitive and specific for the detection of high-grade precursor lesions (i.e., CIN21), and (iii) effective treatment must be provided. We review the evidence that HPV DNA screening from swabs collected by the women in their home or village is sufficiently sound for consideration as a primary screening strategy in the developing world, with sensitivity and specificity for detection of CIN21 as good or better than Pap smear cytology and VIA. A key feature of a self-collected HPV testing strategy (SC-HPV) is the move of the primary screening activities from the clinic to the community. Efforts to increase the affordability and availability of HPV DNA tests, community education and awareness, development of strong partnerships between community advocacy groups, health care centers and regional or local laboratories, and resource appropriate strategies to identify and treat screen-positive women should now be prioritized to ensure successful public health translation of the technologic advancements in cervical cancer prevention.

The Role of Proteomics in the Diagnosis and Treatment of Women's Cancers: Current Trends in Technology and Future Opportunities

Technological and scientific innovations over the last decade have greatly contributed to improved diagnostics, predictive models, and prognosis among cancers affecting women. In fact, an explosion of information in these areas has almost assured future generations that outcomes in cancer will continue to improve. Herein we discuss the current status of breast, cervical, and ovarian cancers as it relates to screening, disease diagnosis, and treatment options. Among the differences in these cancers, it is striking that breast cancer has multiple predictive tests based upon tumor biomarkers and sophisticated, individualized options for prescription therapeutics while ovarian cancer lacks these tools. In addition, cervical cancer leads the way in innovative, cancer-preventative vaccines and multiple screening options to prevent disease progression. For each of these malignancies, emerging proteomic technologies based upon mass spectrometry, stable isotope labeling with amino acids, high-throughput ELISA, tissue or protein microarray techniques, and click chemistry in the pursuit of activity-based profiling can pioneer the next generation of discovery. We will discuss six of the latest techniques to understand proteomics in cancer and highlight research utilizing these techniques with the goal of improvement in the management of women's cancers.

Testing for human papillomavirus in cervical cancer screening: a review of indications and methodology

High-risk human papillomavirus (hrHPV) testing has become an integral component of cervical cancer screening, given that persistent infection with hrHPV was recognized as a significant risk factor for most precancers and cancers of the cervix. Particularly, testing for hrHPV types (in conjunction with cervical cytology) has been approved for primary screening in women over 30 years of age and for cost-effective triaging of equivocal cervical cytology results. HPV was a small double-stranded DNA virus that cannot be cultured in vitro; so, different types of tests have been developed to detect its presence. Various molecular techniques were available for detecting the presence and/or quantity of hrHPV. In this review, the testing options for hrHPV and its surrogates, with an emphasis on those approved by the US Food and Drug Administration (FDA), were detailed. Cancer (Cancer Cytopathol) 2011;. © 2011 American Cancer Society.

Evaluation of p16INK4a immunohistochemical reactivity in endocervical glandular neoplasia

OBJECTIVE

To determine the expression of p16INK4a by immunohistochemistry in endocervical neoplasms.

METHODS

Forty-nine cases of endocervical glandular neoplasia were identified by record review. On histopathologic review of the original and new slides, 16 cases were identified as endocervical adenocarcinoma in situ (AIS), 31 were identified as invasive adenocarcinoma, and 2 had no remaining tumor identified. A representative paraffin block was selected from each case with tumor and sections cut from each block. One section from each case was stained with hematoxylin and eosin, 1 was processed for immunohistochemical study for p16INK4a, and 1 was a negative control. The nuclear immunoreactivity was graded positive, indeterminate, or negative.

RESULTS

Cases were classified AIS, adenocarcinoma, or no tumor. Of 16 cases of AIS, 15 (93.01%) cases were immunoreactive to p16INK4a; 1 case was negative. All cases of invasive adenocarcinoma, 31 of 31 cases (100%), were immunoreactive to p16INK4a.

CONCLUSIONS

p16INK4a reactivity can be used to help identify and assess in situ and invasive endocervical glandular neoplasms.

High-risk human papillomavirus in esophageal squamous cell carcinoma

BACKGROUND

Although most cases of esophageal squamous cell carcinoma (ESCC) in western populations have been attributed to high levels of exposure to tobacco and alcohol, infectious agents have been postulated as possible causes, particularly human papillomavirus (HPV).

METHODS

To explore this issue, we analyzed HPV DNA prevalence and HPV types together with lifestyle factors, in relation to tumor stage and survival in a low-incidence population. Archived tumor samples from a nationwide cohort of 222 ESCC patients were tested for the presence of HPV DNA by PCR; positive samples were sequenced to determine HPV type, and p16(INK4a) status was assessed by immunohistochemistry.

RESULTS

Of 222 ESCC patients, 8 tested HPV positive (prevalence, 3.6%; 95% confidence interval, 1.1-6.1%), of which 6 were HPV-16 positive and 2 were HPV-35 positive. Four of the eight HPV-positive tumors overexpressed p16(INK4a). None of 55 normal esophageal tissue samples from healthy participants had any detectable HPV. Although the numbers were low, it seemed that patients with HPV-positive ESCC tumors were younger than those with HPV-negative tumors (mean age, 60.8 versus 65.3 years, P = 0.18) and had higher body mass index (BMI) throughout life (mean current BMI of 25.1 for HPV positive, 22.2 for HPV negative, P = 0.08; mean BMI at 20 years of 25.8 for HPV positive, 22.1 for HPV negative, P = 0.003). We found no difference between patients with HPV-positive and HPV-negative tumors with respect to other lifestyle factors.

CONCLUSIONS

These findings suggest a very low prevalence of HPV DNA in human ESCC.

IMPACT

HPV is very unlikely to be a common cause of ESCC in Australia.

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.

p16INK4A overexpression in precancerous and cancerous lesions of the uterine cervix in Tunisian women

Uterine cervix cancer is an important public health problem in developing countries. However, there is a substantial lack of inter-observer diagnostic reproducibility for its precursor lesions (CIN1). The study was performed to evaluate the usefulness of p16(INK4A) overexpression as a surrogate marker for uterine cervix precancerous lesions and high-risk human papillomavirus (HPV) infection. We conducted a retrospective study of 87 uterine cervix specimens, including 7 normal tissue samples, 17 benign lesions, 34 precancerous lesions, 22 invasive squamous cell carcinomas (SCC), and 7 adenocarcinomas. Immunohistochemistry was used to find p16(INK4A) overexpression. HPV infection was detected by PCR. No immunoreactivity for p16(INK4A) was detected in normal tissue or benign lesions. p16(INK4A) immunoreactivity was focal in CIN1, whereas strong and diffuse immunoreactivity for p16(INK4A) was uniformly observed in both the nucleus and the cytoplasm of all CIN2 and 3, as well as in those of invasive SCC and adenocarcinomas. A statistically significant association was observed between p16(INK4A) overexpression, lesion grade, and high-risk HPV infection (p<0.0001). p16(INK4A) overexpression is a useful additional marker for the interpretation of problematic uterine cervical lesions and can help to reduce the variability during evaluation of suspicious biopsies of the uterine cervix.

Papillary squamous intraepithelial lesions of the uterine cervix: human papillomavirus-dependent changes in cell cycle expression and cytologic features

Most human papillomavirus-associated squamous intraepithelial lesions of the uterine cervix are flat; some have papillary architecture that shows a spectrum of differentiation from low-grade squamous intraepithelial lesions to high-grade squamous intraepithelial lesions. For this subset of lesions, there are few data relating human papillomavirus type to cytology and cell cycle activity. Here, we collected 24 cases of papillary squamous intraepithelial lesions with either low-risk (15 cases) or high-risk (9 cases) human papillomavirus infection. We described their morphology and performed immunohistochemical staining with cell cycle-related markers Ki-67, p53, pRb, and P16INK4a. The Ki-67 labeling index was significantly lower in the low-risk group than in the high-risk group (P < .001). A cut point of less than 50% labeling index detected all but one low-risk group case. Degradation of p53 and pRb was less evident in the low-risk group than in the high-risk group (p53, P < .001; pRb, P = .006). P16INK4a produced an unexpectedly high positive rate of staining in the low-risk group (60%). However, a specific top-heavy distribution pattern was noted, with evident nuclear but faint cytoplasmic staining, whereas the high-risk group showed strong full-thickness nuclear and cytoplasmic staining. The detection of these lesions by smear examination was not reliable, given the wide expression pattern. Papillary structure was evident in none. We conclude that cell cycle-related markers are helpful in distinguishing low- and high-risk lesions. The strong p16INK4a staining in the low-risk group may imply that more cell cycle-controlling pressure is elicited in papillary lesions than in flat lesions. The distribution pattern of p16INK4a staining is important when making a diagnosis; cytology is not effective. Human papillomavirus type, histology, and cell cycle markers could clearly separate these lesions into either a low-risk or a high-risk group, properly designated low-grade squamous intraepithelial lesions or high-grade squamous intraepithelial lesions in current management algorithms. Thus, the previously used terms papillary immature metaplasia and immature condyloma, although descriptive for low-risk group lesions, are confusing and should be discarded.

p16 as a diagnostic marker of cervical neoplasia: a tissue microarray study of 796 archival specimens

BACKGROUND

To evaluate the usefulness of this biomarker in the diagnosis of cases of cervical neoplasia we studied the immunohistochemical expression of p16INK4a in a large series of archival cervical biopsies arranged into tissue microarray format.

METHODS

TMAs were constructed with tissue cores from archival formalin fixed, paraffin-embedded donor tissues from 796 patients, and included cases of cervical intraepithelial neoplasia (CIN)1 (n = 249), CIN2 (n = 233), CIN3 (n = 181), and invasive cervical carcinoma (n = 133). p16INK4a expression was scored using two different protocols: 1) positive vs negative p16INK4a staining; 2) a semi-quantitative immunohistochemical score (0 to 8 points) according to the intensity of staining and the proportion of stained cells

RESULTS

p16INK4A expression was not seen in normal cervix tissue, but was found with increasing frequency in the sequence: CIN1 (180/249; 72.3%) - CIN2 (212/233; 91.0%) - CIN3 (178/181; 98.3%) - invasive carcinoma (131/133; 98.5%). Using semi-quantitative scoring, all normal cervical samples had low scores (from 0 to 2 points), whilst the number of specimens with high scores was proportional to the degree of cervical dysplasia or the presence of invasive carcinoma.

CONCLUSION

Immunohistochemical analysis of p16INK4a expression is a useful diagnostic tool. Expression is related to the degree of histological dysplasia, suggesting that it may have prognostic and predicative value in the management of cervical neoplasia.

Screening for HIV-associated anal cancer: correlation of HPV genotypes, p16, and E6 transcripts with anal pathology

BACKGROUND

HIV-positive men with a history of anal-receptive intercourse are at risk for anal cancer. We determined whether human papilloma virus (HPV) biomarkers were correlated with anal pathology in these men.

METHODS

HPV genotype was determined by PCR/line blot assay. Real-time PCR assays were done for viral load, E6 transcripts for HPV genotypes 16, 18, and 31, and p16 transcripts.

RESULTS

The most common oncogenic HPV types were HPV 16 (38%), 18 (19%), 45 (22%), and 52 (19%). HPV types 16, 18, 31, 52, 59, and 68 were associated with high-grade histology. The number of HPV genotypes per anal swab was higher for anal intraepithelial neoplasia (AIN) 2/3 than for normal or AIN 1 histology [median, 5 types (interquartile range) (IQR), 3-7 versus 3.5 (IQR), 2-6; P = 0.0005]. HPV 16 viral load was also associated with AIN 2/3 histology. There was no difference in p16 or E6 transcripts between histologic grades. In the multivariable logistic regression model, HPV genotypes 16 [odds ratio, 2.58; 95% confidence interval (95% CI), 1.31-5.08; P = 0.006] and 31 (odds ratio, 4.74; 95% CI, 2.00-11.22; P = 0.0004), baseline CD4 count < 400 cells/mm(3) (odds ratio, 2.96; 95% CI, 1.46-5.99; P = 0.0025), and Acquired Immunodeficiency Syndrome (AIDS)-defining illness (odds ratio, 2.42; 95% CI, 1.22-4.82; P = 0.01) were associated with high-grade histology after adjusting for age.

CONCLUSIONS

The presence of high-grade anal pathology (AIN 2/3) in HIV-positive men was associated with multiple HPV genotypes, HPV genotypes 16 and 31, and HPV 16 viral load.

The application of markers (HSP70 GPC3 and GS) in liver biopsies is useful for detection of hepatocellular carcinoma

BACKGROUND/AIMS

Liver biopsy for hepatocellular carcinoma (HCC) detection is largely restricted to small hepatocellular lesions, which are often morphologically challenging, requiring careful distinction between dysplastic nodules (high-grade) and well-differentiated HCC.

METHODS

We investigated the diagnostic accuracy of a panel of markers (HSP70 GPC3 and GS), previously tested in resection specimens, in a series of liver biopsies of large regenerative nodules (n=13), low-grade dysplastic nodules (n=21), high-grade dysplastic nodules (n=50), very well-differentiated (VWD) (n=17), well-differentiated (WD-G1) (n=40) and G2-3 (n=35) HCC.

RESULTS

Almost all cases of large regenerative and low-grade dysplastic nodules did not stain while high-grade dysplastic nodules showed 1 marker (22%) but never 2 or 3. For HCC detection the overall accuracy of marker combination was 60.8% (3 markers) and 78.4% (2 markers) with 100% specificity. When restricted to VWD+WD-G1 HCC the accuracy was 57% (3 markers) and 72.9% (2 markers) with 100% specificity.

CONCLUSIONS

This panel proved useful to detect well-differentiated HCC in biopsy. Two immunoreactive markers (out of 3) are recommended as the most valuable diagnostic combination for HCC detection. The diagnostic accuracy of the panel could be improved using additional markers, as suggested by studies of expression profiling in other human models.

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.

High-risk human papillomavirus DNA load in a population-based cervical screening cohort in relation to the detection of high-grade cervical intraepithelial neoplasia and cervical cancer

In a population-based cervical screening cohort, we determined the value of type-specific viral load assessment for the detection of high-grade cervical intraepithelial neoplasia and cervical cancer (>or=CIN2). Viral load was determined by type-specific real-time PCR in women with single HPV16,-18,-31 and -33 infections, as determined by GP5+/6+-PCR. Study endpoints were the detection of cumulative >or=CIN2 or>or=CIN3 within 18 months of follow-up. High viral loads of HPV16,-31, and -33 were predictive for >or=CIN2 (relative risk of 1.6 (95% CI: 1.3-1.9), 1.7 (95% CI: 1.1-2.7) and 1.9 (95% CI: 1.1-3.1) per 10-fold change in viral load, respectively). For HPV18, the relative risk was of similar magnitude (1.5, 95% CI: 0.7-3.1), though not significant (p=0.3). Subsequently, we determined the sensitivities of viral load for >or=CIN2 and >or=CIN3 in HPV DNA-positive women using viral load thresholds previously defined in a cross-sectional study. These thresholds were based on the 25th, 33rd and 50th percentiles of type-specific HPV16,-18,-31 or -33 viral load values found in women with normal cytology. For all types, combined sensitivities for >or=CIN2 were 93.5%, 88.8% and 77.7% for the 25th, 33rd and 50th percentile thresholds, respectively. Response-operator-characteristics (ROC) curve analysis showed that viral load testing on HPV DNA-positive women in addition to or instead of cytology may result in an increased sensitivity for >or=CIN2, but at the cost of a marked decrease in specificity in relation to cytology. Similar results were obtained when using >or=CIN3 as endpoint. In conclusion, in a cervical screening setting viral load assessment of HPV16, 18, 31 and 33 has no additive value to stratify high-risk HPV GP5+/6+-PCR-positive women for risk of >or=CIN2 or>or=CIN3.

New technologies in cervical cancer screening

A shift to a molecular approach to cervical cancer screening is the most likely solution to the goals of improved screening in both the developed and developing world. The impetus for new screening technologies in the developed world is predominately driven by the need to increase positive predictive value and reduce over-management of low-grade and often transient abnormalities (i.e., increase specificity). Rapid tests, where results can be given to a patient within the same visit, are anticipated to have the greatest impact in low resource settings in low and middle income countries (and in disadvantaged sub-populations in high-income countries) where substantial loss to follow up cripples the effectiveness of cervical cancer screening programs. Clinical validation will be required before these tests are implemented in routine screening programs.