Estimation of prognoses for cervical intraepithelial neoplasia 2 by p16INK4a immunoexpression and high-risk HPV in situ hybridization signal types

The present study used immunohistochemical staining and in situ hybridization (ISH) to examine whether progression of cervical intraepithelial neoplasia, grade 2 (CIN 2) can be predicted by p16INK4a immunoexpression and high-risk human papilloma virus (HPV) ISH signal types. We studied 52 cases histologically diagnosed with CIN 2: dysplasia regressed in 28 cases; 13 cases progressed to CIN 3; and CIN 2 persisted in 11 cases. Expression of p16INK4a and high-risk HPV signal both related to grade of CIN. Stronger p16INK4a immunoexpression and a higher frequency of expression of a punctate nuclear signal were observed in CIN 2 lesions before progression compared with those before regression. CIN 2 cases in which moderate to strong immunoexpression of p16INK4a and a punctate signal were observed simultaneously progressed to CIN 3 in 10 (91%) of 11 cases. CIN 2 cases with moderate to strong immunoexpression of p16INK4a and a high-risk HPV punctate signal should be treated because of the great risk of progression.     

Prevalence of human papillomavirus types in cervical lesions from women in rural Western India

Cervical cancer is the most common cancer among women in many areas of India which contributes for a fifth of the global burden of disease. Persistent infection with one of the high-risk human papillomaviruses (HPV) has been established as the cause for cervical cancer and the documentation of the prevalence of HPV types in cervical cancer in different regions of India is useful for a prevention program combining both screening and vaccination. In this study, the HPV type distribution and the frequency of p16(INK4a) immunoexpression have been determined in 125 cases of inflammatory lesions or grade 1 cervical intraepithelial neoplasia, 74 cases of grade 2, 72 cases of grade 3, and 113 cervical cancer cases diagnosed among women from rural Solapur and Osmanabad districts, Maharashtra. The overall prevalence of high-risk HPV was 37.6% in inflammatory lesions or grade 1 cervical intraepithelial neoplasia, 63.5% in grade 2, 97.2% in grade 3 and 92% in cervical cancer cases. HPV 16 and HPV 18 were detected in 80.6% of grade 3 cervical intraepithelial neoplasia and 86.5% of cervical cancer cases. 94.7% of the cervical cancer and 84.4% of the high grade lesions with a strong and full thickness staining for p16(INK4a) were positive for HPV infection; p16(INK4a) immunoexpression increased with worsening grade of cervical intraepithelial neoplasia. The HPV genotyping data showing a high HPV 16 and 18 prevalence in cancer specimens indicate that prophylactic HPV 16/18 vaccination would have a significant impact on the prevention of cervical cancer in India.     

p16(INK4a) as a complementary marker of high-grade intraepithelial lesions of the uterine cervix. I: Experience with squamous lesions in 189 consecutive cervical biopsies

AIM: To test the usefulness of p16(INK4a) immunostaining for improving the diagnostic accuracy of cervical punch biopsies referred to a routine laboratory setting during the investigation of women with abnormal Papanicolaou smears. METHODS: A total of 188 consecutive and unselected colposcopically directed cervical biopsies and a single contemporaneous cervical polyp were accessioned prospectively over a 3-month period, step-serially sectioned and examined by H&E and immunostained for p16(INK4a). The clinical context, results of concurrent Papanicolaou smears/ThinPrep slides and Digene hybrid capture tests for high-risk human papillomavirus (HPV) subtypes, as well as follow-up cervical smears/ThinPrep, biopsies and loop excisions of transformation zones or cone biopsies were all correlated with the morphological and immunohistochemical findings. RESULTS: Seventy-seven biopsies (40.7%) displayed a high-grade squamous intraepithelial lesion (HGSIL; cervical intraepithelial neoplasia [CIN] 2-3), 27 (14.3%) showed a low grade squamous intraepithelial lesion (HPV +/- CIN1) and 85 (45%) showed a range of non-dysplastic (inflammatory or reactive) changes. Diffuse strong parabasal immunostaining for p16(INK4a), suggestive of integrated high-risk HPV DNA into the host genome, was observed in 81 biopsies (42.9%, including the cervical polyp) and correlated (>90%) with HGSIL in the H&E sections. Only one case revealed irreconcilable discordance between the histological features and this strong parabasal immunostaining pattern. Focal and weaker midzonal or superficial p16(INK4a) immunostaining, suggestive of episomal HPV infection, was noted in 19 biopsies (10%) and these biopsies exhibited a range of histological changes but predominantly low grade squamous intraepithelial lesion (LGSIL). No staining of the squamous epithelium was seen in 89 biopsies (47.1%). Again, only one case revealed irreconcilable discordance between the histological features and this negative immunostaining pattern. On review of all cases where discordant results were noted between the H&E appearances and expected p16(INK4a) immunostaining, we found 26 cases (13.7%) in which this discordance prompted justifiable modification of the original diagnosis. CONCLUSIONS: Thus, within a routine diagnostic laboratory, p16(INK4a) immunostaining appears to be a very useful adjunctive test in the examination of colposcopically directed cervical biopsies, in the diagnostic cascade of women investigated for abnormal Papanicolaou smears. It is possible, as further data accumulate concerning the importance of integration of high-risk HPV DNA into the host cell genome and the reliability with which this can be identified by p16(INK4a) immunostaining, that this will become the diagnostic 'lesion of interest', replacing the subjective histological grading of cervical dysplasia, in the management of such patients; i.e., the discriminatory watershed between continued surveillance and active intervention.     

Immunohistochemical expression of p16(INK4a) is predictive of HR-HPV infection in cervical low-grade lesions.

The p16(INK4a) is a cyclin-dependent kinase inhibitor that decelerates the cell cycle by inactivating the cyclin-dependent kinases involved in the phosphorylation of the retinoblastoma protein (RB). Expression of E6 and E7 oncogenes of high-risk (HR) human papillomavirus (HPV), affecting the RB-p16 pathway, leads to p16 upregulation. Although it is widely reported that p16 is overexpressed in a high percentage of preneoplastic lesions and in almost all carcinomas of the uterine cervix, protein upregulation and its correlation with HPV infection in low-grade lesions is still being debated. In this study, we investigated in parallel, p16 expression and HPV infection in 100 cervical biopsies (17 normal tissues, 54 CIN1, 10 CIN2, 11 CIN3, eight invasive squamous cancers). Results obtained demonstrated that none of the 17 normal cervical tissues, evaluated by immunohistochemistry, presented p16 positivity whereas, starting from CIN1 (31%) to CIN2 (90%), CIN3 (100%) and carcinomas (100%), a constant and significant increase of protein overexpression (P<0.0001) was observed. In addition, p16 overexpression consistently showed elevated sensitivity (84%) and specificity (98%) in detecting HR-HPV infection with a high positive predictive value (97%) and negative predictive value (86%). Of interest, 93% of the p16-positive CIN1 were also HR-HPV infected. Our findings confirmed that p16 overexpression is associated to high-grade precancerous lesions and cervical carcinomas, and further demonstrated that immunohistochemical evaluation of p16 may be a useful biomarker in identifying HR-HPV-infected low-grade lesions.     

p16INK4A as a marker for cervical dyskaryosis: CIN and cGIN in cervical biopsies and ThinPrep smears

AIM: To examine the potential of p16(INK4A) as a biomarker for dysplastic squamous and glandular cells of the cervix in tissue sections and ThinPrep smears. METHODS: Immunocytochemical analysis of p16(INK4A) expression was performed on 22 normal cervical tissue samples, five cervical glandular intraepithelial neoplasia (cGIN), 38 cervical intraepithelial neoplasia 1 (CIN1), 33 CIN2, 46 CIN3, and 10 invasive cancer cases (eight squamous and two adenocarcinomas). All samples were formalin fixed and paraffin wax embedded, and immunohistochemical analysis was carried out using a mouse monoclonal anti-p16(INK4A) antibody after antigen unmasking. The staining intensity was assessed using a 0 to 3 scoring system. In addition, the expression status of p16(INK4A) was examined in 12 normal ThinPrep smears, one smear exhibiting cGIN, and a total of 20 smears exhibiting mild, moderate, and severe dyskaryosis. Human papillomavirus (HPV) detection was carried out using a modified SYBR green assay system. Fluorogenic polymerase chain reaction (PCR) and solution phase PCR were used for specific HPV typing. RESULTS: p16(INK4A) immunoreactivity was absent in all normal cervical tissues examined. Dysplastic squamous and glandular cells were positive for p16(INK4A) expression in all cases included in this study, except for one CIN3 case. p16(INK4A) expression was mainly nuclear in CIN1 cases, and both nuclear and cytoplasmic in CIN2, CIN3, cGIN, and invasive cases. All cases positive for HPV expressed the p16(INK4A) protein, although not all cases found positive for p16(INK4A) were HPV positive. In general, the p16(INK4A) staining intensity was lower in cases negative for HPV or those containing a low risk HPV type. CONCLUSION: This pattern of overexpression demonstrates the potential use of p16(INK4A) as a diagnostic marker for cervical squamous and also glandular neoplastic lesions. In addition, the technique can be used to identify individual dyskaryotic cells in ThinPrep smears. Thus, p16(INK4A) is a useful marker of cervical dyskaryosis.     

The predictive value of p16(INK4a) and hybrid capture 2 human papillomavirus testing for high-grade cervical intraepithelial neoplasia

We performed p16(INK4a) immunocytochemical analysis and Hybrid Capture 2 (HC2; Digene, Gaithersburg, MD) high-risk HPV testing on 210 abnormal SurePath (TriPath Imaging, Burlington, NC) Papanicolaou specimens diagnosed as low-grade squamous intraepithelial lesion (LSIL) or high grade squamous intraepithelial lesion (HSIL). The results were compared with 121 follow-up biopsy specimens. p16(INK4a) was positive in 57.9% of women with LSIL compared with 97.1% of women with HSIL. In contrast, HC2 testing was positive in 85.0% of women with LSIL and 86.4% of women with HSIL. The differences in the positive rates for16(INK4a) between LSIL and HSIL was significant (P < .001), whereas, for HC2, it was not (P = .264). In patients who had cervical biopsies following a cytologic diagnosis of LSIL, the positive predictive value (PPV) of p16(INK4a) for a biopsy of cervical intraepithelial neoplasia grade 2 or 3 (CIN2/3; 33.3%) was significantly higher than the PPV of HC2 results (21.2%) (P < .001). Using liquid-based cytology specimens, p16(INK4a) immunocytochemical analysis has a higher PPV than reflex HC2 HPV testing for identifying CIN2/3 among patients with LSIL and might be useful for selecting patients with LSIL for colposcopy.     

Human papillomavirus genotyping by oligonucleotide microarray and p16 expression in uterine cervical intraepithelial neoplasm and in invasive carcinoma in Korean women

For evaluating the diagnostic significance of p16(INK4A) over-expression in the uterine cervical intraepithelial neoplasm and in invasive carcinoma, human papillomavirus (HPV) was detected and genotyped by oligonucleotide microarray in archival tissues of 117 cervical specimens, including 47 invasive squamous cell carcinomas (SCC), 30 cases of cervical intraepithelial neoplasia (CIN), 20 adenocarcinomas, and 20 cases of non-neoplastic cervix. The expression of p16(INK4A) protein was immunohistochemically studied in these cases and in five HPV-positive and one HPV-negative cervical cancer cell lines. HPV was detected in 50% of CIN, 61.7% of SCC, and 45.5% of adenocarcinomas. p16(INK4A) expression was seen in all 20 cases of adenocarcinoma, 78.7% (37/47) of SCC, and 96.7% (29/30) of CIN, but not in any cases of the non-neoplastic cervix. There was no difference in p16(INK4A) expression between the HPV-positive and HPV-negative cervical lesions. All HPV-positive and -negative cervical cancer cell lines expressed p16(INK4A) protein. In conclusion, the presence of p16(INK4A) expression in cervical squamous and glandular epithelium indicates the existence of dysplasia or malignancy in the uterine cervix, regardless of HPV infection.     

Methylation of p16INK4a is a non-rare event in cervical intraepithelial neoplasia.

The cell cycle inhibitor, p16INK4a may be a useful surrogate biomarker of cervical intraepithelial neoplasia (CIN); however, there is currently no consensus of p16INK4a genetic alterations throughout the multiple step process of CIN. Our goal was to identify the methylation frequency of p16INK4a in each step of CIN that is associated with human papillomavirus (HPV) infection, using several different detection methods of p16INK4a methylation to correlate the data. The present study included a total of 43 patients, including 38 with CIN, and 5 normal patients. Three different methods were used to detect hypermethylation of CpG islands, methylation-specific PCR (MSP) amplification of different primer sets of M1, M2, and M3, pyrosequencing of each forward primer region, and immunohistochemistry of p16INK4a. Analysis of MSP showed that 20 of the 38 CIN patients (52.6%) revealed hypermethylation in at least 1 primer set of the p16INK4a promoter. A complete loss of p16INK4a protein expression was observed in 11 cases (28.9%). There was no observed association of methylation of the p16INK4a gene with either CIN grading (P=0.0698) or HPV status (P=0.2811): specifically 42.9% (3/7) was found in CIN 1, 57.1% (8/14) in CIN 2, and 52.9% (9/17) in CIN 3. In concordance with immunohistochemistry results, hypermethylation of the p16INK4a promoter was significantly correlated with a lack of p16 protein expression (P=0.0145). All positive peaks from pyrosequencing matched the MSP results, which ranged from 6.3% to 24.5%. In conclusion, p16INK4a gene silencing during CIN was not determined to be a particularly rare event; however, it does not correlate with either HPV status or CIN grading.     

p16INK4A, CDC6, and MCM5: predictive biomarkers in cervical preinvasive neoplasia and cervical cancer

AIM: To analyse and compare expression patterns of three potential biomarkers-p16(INK4A), CDC6, and MCM5-and evaluate their use as predictive biomarkers in squamous and glandular cervical preinvasive neoplasia. METHODS: Immunocytochemical analysis of p16(INK4A), MCM5, and CDC6 expression was performed on 20 normal, 38 cervical intraepithelial neoplasia 1 (CIN1), 33 CIN2, 46 CIN3, 10 squamous cell carcinoma, 19 cervical glandular intraepithelial neoplasia (cGIN), and 10 adenocarcinoma samples. Staining intensity was assessed using a 0-3 scoring system. p16(INK4A), MCM5, and CDC6 expression was also examined in ThinPrep slides exhibiting mild, moderate, and severe dyskaryosis. Human papillomavirus (HPV) was detected using a modified SYBR green assay. Fluorogenic polymerase chain reaction (PCR) and solution phase PCR were used for specific HPV typing. RESULTS: All three markers showed a linear correlation between expression and grade of dysplasia. p16(INK4A) and MCM5 protein expression was upregulated in all grades of squamous and glandular dysplasia. CDC6 protein was preferentially expressed in high grade lesions and in invasive squamous cell carcinoma. CONCLUSION: p16(INK4A) expression was closely associated with high risk HPV infection-all grades of squamous and glandular cervical lesions were immunohistochemically positive. MCM5 staining intensity was independent of high risk HPV infection, highlighting its potential as a biomarker in both HPV dependent and independent cervical dysplasia. CDC6 may be a biomarker of high grade and invasive lesions of the cervix, with limited use in low grade dysplasia. p16(INK4A) was the most reliable marker of cervical dysplasia. Combinations of dysplastic biomarkers may be useful in difficult diagnostic cases.     

P16(INK4a) expression as a potential prognostic marker in cervical pre-neoplastic and neoplastic lesions

An immunohistochemical analysis with monoclonal antibody p16(INK4a) was performed in formalin-fixed, paraffin-embedded samples of 60 cases. The aim was to investigate in biopsies the expression of p16(INK4a) of normal uterine cervical tissue, pre-cancerous and cancerous lesions, and their relation with human papilloma virus (HPV) and HIV status. Three parameters were evaluated: percentage of p16(INK4a) positive cells, reaction intensity, and cell staining pattern. All of these parameters were statistically different when compared among different histological groups. However, logistic regression model showed that the reaction intensity was the best indicator of the expression of p16(INK4a). This expression increases from normal to invasive squamous carcinoma. Sixty-six percent of the patients with CIN grade 1 (CIN1) expressed p16(INK4a) (all these cases were infected with high risk HPV). Our study supports the hypothesis that p16(INK4a) expression in pre-cancerous lesions and cancers can be used to identify HPV-transformed cells. Of great interest for routine diagnostic use is the fact that immunohistochemical testing for p16(INK4a) seems to be capable of identifying HPV-positive cells and potentially recognizing those lesions with an increased risk of progression to high-grade lesions.     

Assessment of immunohistochemistry for p16INK4 and high-risk HPV DNA by in situ hybridization in esophageal squamous cell carcinoma

The role of high-risk human papillomavirus (HPV) in the pathogenesis of esophageal squamous cell carcinoma (ESCC) remains unclear. p16(INK4) is used as a surrogate marker to detect HPV-related tumors but has had discrepant results in ESCC. In this study, 32 cases of ESCC were examined to determine the relationship between p16(INK4) expression and high-risk HPV. All the tumors were stained by immunohistochemistry for p16(INK4). Tumors having p16(INK4) nuclear and/or nuclear and cytoplasmic expression were considered positive. Tumors positive for p16(INK4) expression were tested for high-risk HPV by in situ hybridization (ISH). In all, 20 cases of ESCC (63%) showed only cytoplasmic staining for p16(INK4), and 11 cases (34%) showed both cytoplasmic and nuclear staining for p16(INK4); 4 cases (13%) showed no staining for p16(INK4). None of the p16(INK4) -positive cases were positive for high-risk HPV by ISH. These results indicate that p16(INK4) expression in ESCC does not correlate with the presence of high-risk HPV DNA by ISH. High-risk HPV does not seem to play a major role in the carcinogenesis of ESCC in low-risk areas.     

An analysis on the combination expression of HPV L1 capsid protein and p16INK4a in cervical lesions

Human papillomavirus (HPV) infection in cervix is the most important reason for cervical cancer, but only 2% cervical HPV infection will develop into cervical cancer. So how to identify patients at risk of progressive cervical lesions from those infected with HPV to avoid over treatment is a big issue in clinic. The aims of this study were to detect the expression of HPV L1 capsid protein and p16^INK4a in cervical lesions and to investigate the combination expression of HPV L1 capsid protein and p16^INK4a in cervical lesions and its diagnostic efficiency in clinic. Immunochemical method was used to detect the expression of HPV L1 capsid protein and p16^INK4a in 169 cases of abnormal cytology. Histopathologic test was performed to identify cervical lesions of all the cases. χ² test and spearman's rank correlation were used for statistical analysis. The diagnostic sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), accuracy, and the area under the receive operating characteristic (ROC) curve (denoted by A_Z) were calculated with SPSS 13.0. All the statistical tests were two sided at the 5% level of significance. L1 expression decreased (P < 0.001), but p16^INK4a expression increased (P < 0.001) with histopathologic diagnosis increasing. The expression rates of HPV L1 capsid protein, p16^INK4a, and L1(?)/p16(+) in cervical intraepithelial neoplasia (CIN)2, CIN3, and squamous‐cell carcinoma were statistically different from those in CIN1 (P < 0.001). The expressions of HPV L1 capsid protein, L1(+)/p16(+), L1(+)/p16(?), and L1(?)/p16(?) were negatively correlated with the severity of cervical lesions (P < 0.001), whereas the expressions of p16^INK4a and L1(?)/p16(+) were positively correlated with the severity of cervical lesions (P < 0.001). The specificity and A_Z of combining L1 with p16 ^INK4a were statistically higher than L1 or p16 ^INK4a alone (P < 0.05). L1 and p16^INK4a are useful biomarkers for the early diagnosis of cervical lesions. The combination of L1 and p16^INK4a has a higher diagnostic accuracy than L1 or p16^INK4a alone in diagnosis of cervical lesions. Diagn. Cytopathol. 2010;38:573–578. © 2009 Wiley‐Liss, Inc.     

Comparison of p16INK4A and Hybrid Capture 2 human papillomavirus testing as adjunctive tests in liquid-based gynecologic SurePath preparations

p16(INK4a), cyclin-dependent kinase inhibitor, is functionally inactivated in many tumors, including cervical cancer. We compared p16(INK4A) immunocytochemical staining and Hybrid Capture 2 (HCII) on SurePath specimens using tissue biopsies (as the gold standard). Their utility in a spectrum of atypical and preneoplastic lesions, and their ability to accurately identify underlying lesions of CIN II or greater was assessed using biopsy follow-up data. One-hundred and seventeen residual SurePath samples were collected: 43 atypical squamous cells of undetermined significance (ASCUS), 47 low-grade (LGSIL), and 27 high-grade (HGSIL) squamous intraepithelial lesions. Two slides were prepared from each sample; one stained with the SurePath autocyte stain and one immunostained using the CINtec p16(INK4a) Cytology Kit (Dakocytomation). High-risk HPV testing was performed using the HCII DNA test (Digene, Gaithersburg, MD). Available tissue biopsy follow-up data was retrieved. p16(INK4a) was positive in 32.6% (14/43) ASCUS, 46.8% (22/47) LGSIL, and 48.1% (13/27) HGSIL specimens. HCII DNA test was positive in 41.9% (18/43) ASCUS, 78.7% (37/47) LGSIL, and 96.3% (26/27) HGSIL samples. The sensitivity, specificity, positive (PPV) and negative (NPV) predictive values of p16(INK4a) and HCII were: 58.7% and 89.8%, 58.6% and 34.6%, 69.2% and 72.1%, 47.2% and 64.3%, respectively. In patients with cervical biopsies, the PPV of HCII (92.3%) results for a biopsy with CINII/III was significantly higher than the PPV of p16(INK4a) (52%) (P=0.001). Using liquid-based cytology specimens, HCII is a more sensitive test than p16(INK4a) for detection of abnormal cytology. HCII has a higher PPV than p16(INK4a) for identifying CIN II/III.     

p16INK4a immunoexpression: surrogate marker of high-risk HPV and high-grade cervical intraepithelial neoplasia

p16INK4a has emerged as a valuable surrogate marker for high-risk human papillomavirus infection and shows increased immunoexpression with worsening grades of cervical intraepithelial neoplasia (CIN). Numerous studies have emerged in recent years supporting its role in the detection of high-grade dysplasia and have lead to the use of p16INK4a immunohistochemistry in many laboratories. However, only a few studies have examined the possible predictive or prognostic value of p16INK4a in CIN or cervical cancer. This review addresses some of the practical issues in the application of p16INK4a in everyday practice, with an emphasis on integrating the extensive data that have emerged in the literature on p16INK4a immunoreactivity in CIN. The potential role of p16INK4a immunohistochemistry in the prediction of CIN progression is also discussed.     

Immunostaining of p16INK4a/Ki-67 and L1 Capsid Protein on Liquid-based Cytology Specimens Obtained from ASC-H and LSIL-H Cases

Background: Atypical squamous cell cannot exclude high-grade squamous intraepithelial lesion (ASC-H) and low-grade intraepithelial lesion cannot exclude high-grade squamous intraepithelial lesion (LSIL-H) are ambiguous diagnostic entities for the prediction of high-grade cervical lesion. Objective and reproducible tests for predicting high-grade cervical lesions are needed to reduce unnecessary colposcopic referrals or follow-ups.Objective: We aimed to identify an adequate set of adjunctive markers to predict cervical intraepithelial neoplasia grade 2+ (CIN2+) in residual liquid-based cytology specimens (LBCS).Methods: We conducted p16 ^INK4a/Ki-67 and L1 capsid protein immunostaining and human papillomavirus (HPV) DNA typing on 56 LBCS diagnosed with ASC-H or LSIL-H, all of which were subjected to histologic confirmation or follow-up cytologic examination.Results: Positivity for p16 ^INK4a/Ki-67 was associated with a histology of CIN2+ (P=0.047) and CIN3+ (P=0.002). Negativity for L1 capsid protein was associated with CIN2+ confirmed at follow-up (P=0.02).Positivity for high-risk HPV (HR-HPV) was associated with CIN2+ confirmed at follow-up (P=0.036) and a histology of CIN2+ (P=0.037). The sensitivity, specificity, positive predictive value, and negative predictive value for predicting follow-up CIN2+ were 76.2%, 51.4%, 48.5%, and 78.3%, respectively, for p16 ^INK4a/Ki-67 immunostaining; 95.2%, 34.3%, 46.5%, and 92.3%, respectively, for L1 capsid protein; and 66.7%, 67.7%, 54.5%, and 77.8%, respectively, for HR-HPV. The classification and regression tree analysis showed that the combined results of p16 ^INK4a/Ki-67 andL1 capsid protein immunostaining and the HR-HPV test, conducted sequentially, correctly classified 81.8% of samples (27/33)in the prediction of a histology of CIN2 + in ASC-H or LSIL-H. For determination of the histology of cervical intraepithelial neoplasia grade 3+ (CIN3+)in ASC-H or LSIL-H, we found that the combined results of p16 ^INK4a/Ki-67 and L1 capsid protein immunostaining correctly classified 78.8% (26/33) of samples.Conclusions: p16^INK4a/Ki-67 and L1 capsid protein immunostaining and HR-HPV testing of residual LBCS diagnosed with ASC-H or LSIL-H are useful objective biomarkers for predicting CIN2+. Immunostaining for p16^INK4a/Ki-67 and L1 capsid protein are sufficient to predict CIN3+.     

High‐risk human papillomavirus load and biomarkers in cervical intraepithelial neoplasia and cancer

The purpose of this study was to examine the implication of high‐risk human papillomavirus (HPV) load in cervical intraepithelial neoplasia (CIN) and cancer, and to detect biomarkers in cervical disease. We conducted high‐risk HPV DNA load and cervical cytology tests in 343 women, cervical tissue biopsy in 143 women, and immunohistochemistry for p16^INK4A, cyclin D1, p53, cyclooxygenase‐2, Ki‐67, GLUT1, hPygopus2, and beta‐catenin. As a result, HPV load [relative light units (RLU) value] was correlated with the histological severity of cervical disease (p < 0.05). In the ‘atypical squamous cells of undetermined significance’ cytology group, 2.385 of HPV load seemed to be the cut‐off value at which ‘benign’ or CIN I can be differentiated from ‘CIN II or more severe’ (AUC = 0.712), but not statistically significant. The relative risk (odds ratio) of p16^INK4A and GLUT1 overexpression increased gradually according to the histological severity of cervical disease. The p16^INK4A showed statistically significant odds ratios in CIN II, CIN III, and cancer; GLUT1, in CIN II and CIN III; hPygopus2, in CIN III; and beta‐catenin, in CIN III and cancer. Conclusively, HPV load, p16^INK4A, and GLUT1 can be instrumental in predicting the severity of HPV‐related cervical disease. The beta‐catenin/hPygopus2 signaling may be involved in proceeding to CIN III.     

Testing for high‐risk HPV in cervical and tonsillar paraffin‐embedded tissue using a cartridge‐based assay

This study evaluates the suitability of Xpert HPV (Cepheid, Sunnyvale, CA, USA) test for cervical and tonsillar formalin‐fixed paraffin‐embedded (FFPE) tissue samples as compared to the tests currently used in diagnostics. Cervical biopsies and liquid cytology (LC) samples were collected from 48 women attending colposcopy. Biopsies were processed for histology and tested for hrHPV using Xpert HPV. LC samples were tested using Xpert and Hybrid Capture 2 (HC2; Qiagen, Hilden, Germany) tests. Also 29 archived tonsillar carcinoma samples were tested using Xpert, and the results were compared with histology and immunohistochemical p16INK4a (p16) staining. Among valid cervical LC samples 46.8% were hrHPV positive using Xpert test and 55.3% with HC2. The sensitivity of Xpert was 84.6% as compared to HC2, and overall test concordance was 91.5%. Test concordance between valid Xpert results from biopsies and LC samples was 84.6%. Among valid tonsillar samples 70.4% were hrHPV positive, and concordance of 96.3% was found between Xpert and p16 staining. To conclude, Xpert HPV test cartridge provides a convenient platform to test individual samples, including FFPE samples. Further studies are needed to establish whether test sensitivity is sufficient to reliably differentiate between hrHPV positive and hrHPV negative head and neck carcinomas.     

Immunocytochemical staining of p16INK4a protein from conventional Pap test and its association with human papillomavirus infection

The p16INK4a protein is immunocytochemically detected in liquid-based (LB) specimens as a diagnostic marker of cervical dysplasia and neoplasia. Its up-regulation is promoted by high-risk human papillomavirus (HR-HPV) infection. We aimed to detect p16INK4a on conventional Papanicolaou (Pap) test (CPT) slides and to determine the relationship between its overexpression and HR-HPV infection. CPT and LB Pap test (LBPT) slides (165 samples of each) were examined by immunocytochemical staining for p16INK4a. After polymerase chain reaction (PCR), HPV-DNA was genotyped by dot blot hybridization. The CPT slides displayed more numerous dispersed squamous cells and LBPT slides had a clearer background. Positive p16INK4a on CPT occurred in 0% (0/30), 52.5% (21/40), 54.3% (19/35), 100% (30/30), and 100% (30/30) in normal, atypical squamous cells of undetermined significance (ASCUS), low-grade squamous intraepithelial lesions (LSILs), high-grade SILs (HSILs), and squamous cell carcinomas (SCCs) cases, respectively. LBPT slides showed comparable results but were less sensitive. HPV-DNA was detected in 86.7, 70, 45, 57.14, and 10% in SCCs, HSILs, ASCUS, LSILs, and normal cervical cells, respectively. Because HR-HPV was identified in all HPV+ samples of high-grade dysplasia (HSILs and SCCs) and all positive p16INK4a samples infected with HR-HPV, the association of p16INK4a overexpression with HR-HPV infection was confirmed. This study suggests that immunocytochemical staining of p16INK4a on CPT slides is convenient and cost-effective for cervical cancer screening by the detection of dysplastic cells infected with HR-HPV.     

p16(INK4a) expression correlates with degree of cervical neoplasia: a comparison with Ki-67 expression and detection of high-risk HPV types.

Although recent studies have suggested that p16(INK4a) may be a useful surrogate biomarker of cervical neoplasia, Ki-67 and human papillomavirus testing have also been shown to be useful in detecting neoplasia. To help delineate the utility of p16(INK4a), biopsy samples (n = 569: negative, 133; reactive, 75; atypical, 39; low grade, 76; moderate, 80; and severe intraepithelial neoplasia, 113; also, squamous cell carcinoma, 46; adenocarcinoma, 7) were analyzed by immunohistochemistry for expression of p16(INK4a) and Ki-67 (n = 432), as well as by in situ hybridization for human papillomavirus Type 16 (n = 219). Testing for high-risk human papillomavirus types by polymerase chain reaction and HybridCapture2 was performed on concurrent cervical swab specimens. Recuts of the original blocks were reexamined (n = 198). Endometrial biopsies (n = 10) were also analyzed for p16(INK4a) expression. Degree of p16(INK4a) and Ki-67 expression correlated with degree of cervical neoplasia (P <.001) and with presence of high-risk human papillomavirus types (P <.001). There was no relationship between p16(INK4a) overexpression and inflammation or hormonal status. Ki-67 expression correlated with inflammation (P = 0.003) and was expressed in more reactive and atypical lesions than p16(INK4a) (P = 0.008). Probes for human papillomavirus 16 stained 54% of cervical neoplastic lesions; the degree of staining correlated significantly with degree of neoplasia (P <.001) and p16(INK4a) staining (P <.001). Interobserver reproducibility was substantial for p16(INK4a) and Ki-67 interpretation (weighted kappa: 0.74 and 0.70, respectively). Expression of p16(INK4a) was observed in all endometrial biopsies. Compared with Ki-67 expression and detection of high-risk human papillomavirus, p16(INK4a) was less likely to be positive in samples from women with negative, reactive, and atypical biopsies. Although expression of p16(INK4a) in endometrial epithelium may be problematic in terms of screening, the potential of p16(INK4a) as a screening test warrants investigation.     

P16<Superscript>INK4a</Superscript> expression and progression risk of low-grade intraepithelial neoplasia of the cervix uteri

The aim of the study was to evaluate the immunohistochemical expression of p16^INK4a as a marker of progression risk in low-grade dysplastic lesions of the cervix uteri. p16^INK4a immunohistochemistry was performed on 32 CIN1 with proven spontaneous regression of the lesion in the follow-up (group A), 31 (group B) with progression to CIN3 and 33 (group C) that were randomly chosen irrespective of the natural history of the lesion. p16^INK4a staining pattern was scored as negative (less than 5% cells in the lower third of dysplastic epithelium stained), as focally positive (25%) and as diffuse positive (>25%). A diffuse staining pattern was detected in 43.8% of CIN1 of group A, 74.2% of group B and 56.3% of group C. No p16^INK4a staining was detected in 31.3% and 12.9% CIN1 lesions of groups A and B, respectively. Overall, 71.4% and 37.8% of p16^INK4a-negative and diffusely positive CIN1 had regressed at follow-up, whereas 28.6% and 62.2% negative and diffusely positive CIN1 were progressed to CIN3, respectively (P<0.05). All CIN3 lesions analyzed during follow-up of group B were diffusely stained for p16^INK4a. Although p16^INK4a may be expressed in low-grade squamous lesions that undergo spontaneous regression, in this study, CIN1 cases with diffuse p16^INK4a staining had a significantly higher tendency to progress to a high-grade lesion than p16^INK4a-negative cases. p16^INK4a may have the potential to support the interpretation of low-grade dysplastic lesions of the cervix uteri.