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.     

Human papillomavirus genotyping and p16INK4a expression in cervical intraepithelial neoplasia of adolescents.

Adolescents have high rates of human papillomavirus (HPV) infection, and persistent high-risk HPV infection can lead to the development of cervical cancer. The cyclin-dependent kinase inhibitor, p16(INK4a) is overexpressed in cervical intraepithelial neoplasia (CIN), probably due to a persistent and integrated HPV infection. This study investigated p16(INK4a) expression, grades of CIN, and high-risk HPV infection in adolescent cervical biopsies. Biopsies were immunohistochemically stained for p16(INK4a). The presence of wide-spectrum, low-risk, or high-risk HPV was determined by amplifying DNA extracted from the cervical biopsies. Biopsies were classified as cervicitis, 15 cases; CIN 1, 48 cases; CIN 2, 46 cases, and CIN 3, 52 cases. The distribution of p16(INK4a) staining was graded as patchy, diffuse basal, and diffuse full thickness. Pearson's chi(2) tests analyzed the relationships between p16(INK4a) staining, HPV infection, and CIN. Biopsies of cervicitis were negative for HPV and for p16(INK4a) expression. High-risk HPV 16, 18, and 31 increased from 18% in CIN 1 to 66% in CIN 2/3 (P<0.001). In CIN 1, p16(INK4a) was positive in 44% of biopsies with 35% showing patchy, 7% diffuse basal, and one case (2%) showing diffuse full thickness staining. In CIN 2/3, p16(INK4a) was positive in 97% of biopsies with 23% showing patchy, 21% diffuse basal, and 53% diffuse full thickness staining. The difference in the proportions of biopsies showing patchy p16(INK4a) staining in CIN 1 and diffuse full thickness staining in CIN 2/3 was significant (P<0.001). In CIN 1, 61% of high-risk HPV-positive biopsies were p16(INK4a) negative, while all high-risk HPV-positive CIN 2/3 biopsies were p16(INK4a) positive. Diffuse, full thickness p16(INK4a) expression discriminated low-grade from high-grade CIN and appears to be a marker of persistent high-risk HPV infection.     

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.     

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.     

Monoclonal expansion with integration of high-risk type human papillomaviruses is an initial step for cervical carcinogenesis: association of clonal status and human papillomavirus infection with clinical outcome in cervical intraepithelial neoplasia

To define the natural history of cervical intraepithelial neoplasia (CIN) as related to clonal status, we evaluated 20 cases of CIN1 and 18 cases of CIN2 that had been clinically followed for 7 to 48 months at Osaka University Hospital. These included 10 cases that progressed, 15 cases that persisted, and 13 cases that regressed. We analyzed the clonal status of each case by analysis of the pattern of X-chromosomal inactivation. Human papillomavirus (HPV) infection was detected by PCR-RFLP analysis. CINs that are monoclonal or infected by high-risk HPVs are more likely to progress or persist than cases that are polyclonal or negative for high-risk HPVs (p = 0.009 for monoclonal vs polyclonal, p = 0.024 for high-risk HPV positive vs negative p = 0.024). Eighteen (90%) of 20 monoclonal, high-risk HPV-associated CINs progressed or persisted, whereas 9 (60%) of 15 polyclonal or high-risk HPV-negative CINs regressed. Therefore, the combination of clonality status and high-risk type HPV infection was significantly correlated with clinical outcome (p = 0.003). The physical status of the HPV genome was evaluated in 17 cases of HPV-16 positive CINs by real-time PCR. Of those, the HPV viral genome was present in both episomal and integrated forms in 14 CINs (84%), and 12 of these cases (86%) were monoclonal in composition. By contrast, all three CINs in which the HPV genome was present in episomal form were polyclonal. In one CIN1 that was polyclonal, HPV-16 was originally present in episomal form but after 24 months, the patient developed a monoclonal CIN3 in which the HPV-16 genome was present in mixed form. These results may imply that HPV viral integration into the host genomic DNA is associated with progression from polyclonal to monoclonal status in CIN. These events may play a fundamental role in the progression from low-grade to higher grade dysplasia of the cervical mucosa.     

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.     

Evaluation of a commercialized in situ hybridization assay for detecting human papillomavirus DNA in tissue specimens from patients with cervical intraepithelial neoplasia and cervical carcinoma

To evaluate a commercialized in situ hybridization (ISH) assay for detecting human papillomavirus (HPV) DNA, we compared the ability of a new ISH probe, Inform HPV III (Ventana Medical Systems, Tucson, AZ), to that of PCR assays to detect HPV DNA in cervical tissue specimens with normal cervix (20 cases), cervical intraepithelial neoplasia (CIN; CIN 1, 27 cases; CIN 2, 28 cases; and CIN 3, 33 cases), and cervical carcinoma (29 cases). General HPV DNA was detected using consensus primer-mediated PCR assays. HPV genotyping was performed by using EasyChip HPV blot (King Car Yuan Shan Institute, I-Lan, Taiwan). HPV16 integration status (E2/E6 ratio) was determined by using quantitative real-time PCR. Our findings showed that the ISH and PCR had fair to good agreements in detecting HPV DNA across all CIN categories without significant differences (Kappa coefficient, 0.34 to 0.63; P = 0.13 to 1.0). However, ISH detected significantly fewer HPV-positive cases in carcinoma than PCR did (Kappa coefficient, 0.2; P = 0.03). Eleven cases with ISH⁻ PCR⁺ results had HPV types that can be detected by Inform HPV III. Five carcinoma cases with ISH⁻ PCR⁺ results showed a significantly higher level of integrated HPV16 (P = 0.008) than did the ISH⁺ cases. As a consequence, lower copy numbers of episomal HPV16 in carcinoma might be the cause for the false-negative ISH results. Although the punctate signal pattern of HPV significantly increased with the severity of disease (P trend = 0.01), no significant difference in the HPV16 integration status was observed between the cases with a punctate signal only and the cases with mixed punctate and diffuse signals (P = 0.4). In conclusion, ISH using the Inform HPV III probe seems comparable to PCR for detecting HPV DNA in cervical tissue with CINs. False-negative ISH results appear to be associated with the lower copy numbers of the episomal HPV16 but not with the ability of the Inform HPV III probe to detect specific HPV types. In addition, signal patterns, especially a mixed punctate and diffuse pattern of HPV, cannot be reliably used to predict viral integration status.     

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) 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.     

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.     

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.     

人乳头状瘤病毒不同型别与宫颈病变的相关性研究

目的探讨人乳头状瘤病毒（ＨＰＶ）不同型别与宫颈病变性质的关系。方法应用ＰＣＲ技术和原位杂交方法对６１例宫颈上皮内瘤（ＣｅｒｖｉｃａｌｉｎｔｒａｅｐｉｔｈｅｌｉａｌＮｅｏｐｌａｓｉａＣＩＮ）和１２例宫颈鳞癌（ＳＣＣ）进行ＨＰＶ６Ｂ／１１、１６、１８ＤＮＡ检测。结果ＰＣＲ检测结果显示ＨＰＶ６、１１主要分布于低度鳞状上皮内病变（６１９％）和一部分ＣＩＮⅡ中（２０％），而在ＣＩＮⅢ和ＳＣＣ中检测不到；ＨＰＶ１６、１８的检出率随ＣＩＮ级别增高而增加，在ＳＣＣ中高达８３３％。原位杂交结果显示在低度鳞状上皮内病变中，地高辛（Ｄｉｇ）标记的ＨＰＶ６Ｂ／１１、１６、１８ＤＮＡ杂交物质在核中均呈细颗粒状，为“游离型”。上述杂交阳性信号形态亦出现于ＣＩＮⅡ的所有ＨＰＶ６Ｂ／１１及部分ＨＰＶ１６、１８型感染中，而ＣＩＮⅢ和宫颈鳞癌及部分ＣＩＮⅡ中，其杂交阳性信号均为非颗粒状的“整合型”。结论低度鳞状上皮内病变是以ＨＰＶ６、１１低危型为主的多型别病毒的繁殖性感染，ＣＩＮⅢ和宫颈鳞癌为ＨＰＶ１６、１８高危型病毒的整合型感染，而在ＣＩＮⅡ中存在着ＨＰＶ６，１１和ＨＰＶ１６，１８的繁殖性感染及ＨＰＶ１６，１８的整合型感染     

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.     

P16 overexpression and human papillomavirus infection in small cell carcinoma of the uterine cervix

Carcinogenesis of cervical cancer has been investigated, and p16(INK4a) overexpression in squamous cell carcinoma of the cervix has been reported as a result of infection by human papillomavirus (HPV) (eg, HPV 16), and the consequence of the retinoblastoma (Rb) protein inactivation by HPV E7 protein. However, to our knowledge, there have been no studies on the relation between p16(INK4a) overexpression associated with HPV and small cell carcinoma of the cervix, which behaves more aggressively clinically than squamous cell carcinoma. The purpose of this study was to determine whether p16(INK4a) is overexpressed in small cell carcinoma, and if p16(INK4a) is overexpressed, the types of HPV that are related to this cancer. We reviewed 10 cases of small cell carcinoma and examined them for p16(INK4a) overexpression by immunohistochemistry. We also performed HPV typing with polymerase chain reaction (PCR)-sequencing analysis and in situ hybridization and found that p16(INK4a) was overexpressed in every case. PCR-sequencing analyses revealed that all cases were HPV-positive and that 9 cases were positive for HPV 18. Five of the 9 cases positive for HPV 18 were also positive by in situ hybridization and yielded a punctate signal, considered to represent the integrated form. In conclusion, p16(INK4a) was overexpressed and HPV 18 was frequently detected in an integrated form in small cell carcinoma. Therefore, inactivation of Rb protein by HPV 18 E7 protein may be associated with carcinogenesis of small cell carcinoma the same as inactivation of Rb protein by HPV 16 E7 protein is associated with carcinogenesis of squamous cell carcinoma.     

Clinical significance of signal pattern of high-risk human papillomavirus using a novel fluorescence in situ hybridization assay in cervical cytology

The present study aimed to evaluate a novel fluorescence in situ hybridization (FISH) assay for detecting the high-risk human papillomavirus (HR-HPV) DNA and signal pattern in cervical cytology specimens and for identifying cervical intraepithelial neoplasia (CIN) lesions. One hundred and ninety-six liquid-based cytology specimens with CIN were recruited. The signal pattern (punctate, mixed punctate and diffuse, and diffuse) detected by FISH was compared with E6 mRNA and correlated with histological classification. FISH and E6-type specific polymerase chain reaction (PCR) had fair to good agreement for detecting HPV DNA across all grades of CIN (kappa coefficient, 0.37–0.73). Among 44 samples of negative FISH and positive E6 type-specific PCR in HPV 16, 18, 31, 33, 52 and 58, 82% (36/44) of E6 mRNA were not detected, in contrast to 41% (48/118) of positive FISH and positive E6 type-specific PCR (p <0.0001). Among HR-HPV DNA positive cases tested by the FISH assay, the specificity of predicting CIN3 using the punctuate pattern is higher than that using E6 mRNA (96.3% vs. 44.8%). The punctate pattern was 0% in patients with <CIN1 lesions, 8.7% for CIN1 lesions, 6.1% for CIN2 lesions, and 34.0% for CIN3 lesions (p 0.001). The odds ratios were 8.7-fold higher (2.7–27.8, p <0.0001) for the punctate pattern versus the mixed punctate and diffuse pattern, and the diffuse pattern, for predicting CIN3 lesions. The novel FISH assay is comparable to PCR for detecting HPV DNA in cervical cytology with CIN lesions. The punctate signal pattern detected by the FISH assay can be more biologically and clinically relevant for clinically detecting CIN3 lesions.     

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+.     

Cell cycle biology of fibrolamellar hepatocellular carcinoma

Context: Fibrolamellar hepatocellular carcinoma (FLHCC) has a better prognosis than conventional hepatocellular carcinoma. Nevertheless, FLHCC has a propensity to recur with limited responsiveness to chemotherapy. Objective: The purpose of this study was to provide insight into the cell cycle biology of FLHCC, as it relates to FLHCC''s relatively indolent nature and lack of chemoresponsiveness. Design: In seven cases of FLHCC, we assessed: 1. immunoexpression of protein analytes indicating cell cycle progression including Ki-67 (G1, S, G2 and M phases) and S-phase kinase-associated protein (Skp) 2 along with the mitotic index (MI); 2.immunoreactivity for cyclin-dependent kinase inhibitors of cell cycle progression from G1 to S phase, p27Kip1 and p16INK4. Results: The mean percentage of Ki-67 nuclear positivity in neoplastic hepatocytes ranged from 1.0% to 29.7%. Nuclear Skp2 immunoexpression was not observed in any of the cases. The mitotic index was very low (0-1 mitotic figure / 10 high-power fields). All cases showed moderate to strong nuclear p16INK4 positivity (diffuse in five and focal in two). Contras-tively, the adjacent non-neoplastic hepatocytes expressed only mild (2 cases) to no (3 cases) p16INK4. Conclusion: Our analysis has revealed that cell cycle arrest in FLHCC occurs in G0G1 phase and is associated with overexpression of the cell cycle regulator, p16INK4 in tumoral cell nuclei compared with non-neoplastic hepatocytes. In conjunction with our previous immunohistochemical demonstration of a constitutively activated nuclear factor (NF)-kappaB pathway and stemness characteristics of FLHCC with limited differentiation, this cell cycle arrest elucidates the biology of FLHCC''s indolent nature and relative chemoresistance.     

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.     

Immunohistochemical assessment of p16, COX-2 and EGFR in HPV-positive cervical squamous intraepithelial lesions

The protein capsid L1 of the human papilloma virus (HPV) - a key factor in the cervical carcinogenesis - is considered, together with p16, EGFR and COX-2, a characteristic marker for the evaluation of the malignancy progression and prognostic, in terms of tumoral aggressiveness. The purpose of the present study was to make a comparative assessment between the immunohistochemical pattern of p16, EGFR and COX-2 and immunochemical expression of L1 HPV capsid protein, in low grade and high-grade cervical squamous intraepithelial lesions, in order to determine the relationship of these tumoral markers with the infection status of HPV, and their practical applicability in patients diagnosis and follow-up. The study group included 50 women with cytological and histopathological confirmed LSIL (low grade SIL) and HSIL (high-grade SIL). The immunoexpression of L1 HPV protein was assessed on conventional cervico-vaginal smears and EGFR, COX-2 and p16 were immunohistochemically evaluated on the corresponding cervical biopsies. From all cervical smears, the HPV L1 capsid protein was expressed in 52% of LSIL and 23% of HSIL. From all cervical biopsies, p16 was positive in 64% of LSIL, 82% of CIN2 and 100% of CIN3, EGFR was overexpressed in 67% of HSIL (56% CIN2 and 43% CIN3) and 32% LSIL. For COX-2, the Allred score was higher in HSIL when compared to LSIL. Our data revealed 33 cases belonging to both LSIL and HSIL categories with the same Allred score. Immunochemical detection of L1 capsid protein, on cervico-vaginal smears, indicates an immune status induced by the HPV infection and may offer prognosis information, mainly in LSIL lesions. The assessment of p16, EGFR, and COX-2 allows to an integrative approach for the progression of squamous intraepithelial lesion, associated or not with the HPV infection.     

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

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