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

Utility of p16INK4a expression for the interpretation of uterine cervical biopsies in Kenya

Introduction

histologic interpretation of hematoxylin and eosin-stained cervical biopsies is subject to substantial discordance among pathologists. Immunohistochemical staining for p16INK4a can reduce inter-observer disagreement. We did a cross-sectional study to evaluate the utility of p16INK4a staining in the assessment of cervical biopsies in Nairobi, Kenya.

Methods

hematoxylin and eosin-stained sections from 91 colposcopic biopsies diagnosed as negative for dysplasia or as cervical intraepithelial neoplasia (CIN) grade 1-3 from 2011-2013 in Nairobi, Kenya, were reviewed and immunostained for p16INK4a. Agreement in interpretation of cervical biopsies was compared between primary and consensus review results.

Results

on primary evaluation, 16 cases were negative for squamous dysplasia; 23 were CIN 1; 37 CIN 2; and 15 CIN 3. On consensus review, 32 cases were negative for dysplasia; 19 were CIN 1; 16 CIN 2 and 24 CIN 3. Agreement was moderate between primary and consensus histology review results for the diagnosis of low-grade versus high-grade squamous intraepithelial lesions (Kappa = 0.568). None of the cases negative for dysplasia were positive for p16INK4a expression, but in primary and consensus review results, 17% and 5% cases of CIN 1; 49% and 69% of CIN 2, and 80% and 96% of CIN 3 were p16INK4a positive, respectively.

Conclusion

there was significant variability in the interpretation of cervical biopsies on hematoxylin and eosin between primary and consensus review assessments. 75% of CIN 1 cases that were upgraded to CIN 2 during consensus review expressed p16INK4a. These findings demonstrate the role of p16INK4a in increasing diagnostic accuracy and as a marker of high-grade CIN 2/3.

P16INK4A expression might be associated with a favorable prognosis for cervical adenocarcinoma via dysregulation of the RB pathway

Previous studies have largely failed to clarify the relationship between p16^INK4A status and cervical adenocarcinoma prognosis. The current study aimed to examine the clinical and pathological significance of p16^INK4A expression in several cervical adenocarcinoma subtypes. Eighty-two samples collected from patients with cervical adenocarcinoma were formalin fixed and paraffin embedded. Next, p16^INK4A levels were analyzed with immunohistochemistry. Additionally, the relationship between p16^INK4A expression and clinicopathological factors as well as prognosis was evaluated. The expression of p16^INK4A was mostly detected in all usual cervical adenocarcinoma subtypes. In the gastric type, only a few cases were positive for p16^INK4A expression. Results of the Kaplan–Meier analysis indicated that the positive p16^INK4A expression in tumor cells was significantly associated with favorable progression-free survival and overall survival in patients with cervical adenocarcinoma (p = 0.018 and p = 0.047, respectively, log-rank test). Our findings suggest that the status of p16^INK4A expression may influence prognosis. Thus, p16^INK4A expression could be used as a biomarker for improving the prognosis of patients with cervical adenocarcinoma.

In situ expressions of protein 16 (p16CDKN2A) and transforming growth factor beta-1 in patients with cervical intraepithelial neoplasia and cervical cancer

OBJECTIVES

Protein 16 (p16^CDKN2A) and transforming growth factor-beta 1 (TGF- β1) are important tumor suppressor molecules. The aim of this study was to evaluate the frequency and simultaneous expression of p16^CDKN2A and TGF- β1 in cervical intraepithelial neoplasia (CIN) and cervical cancer and their relationship whit the neoplasia progression.

STUDY DESIGN

To evaluate the expressions of p16^CDKN2A and TGF- β1 an immunohistochemical study of both proteins in 75 cervical tissues (24 CIN I, 17 CIN II, 15 CIN III and 19 squamous cell cancer) was performed.

RESULTS

Increased expression of epithelial and stromal p16^CDKN2A in all grades of CIN and cancer was observed. Healthy controls were negative. The frequency of p16^CDKN2A expression in the patients was as follow: 75% in CIN I and 100% in CIN II, CIN III and cancer. TGF- β1 expression was found increased in all patients with CIN I and CIN II and decreased in CIN III and cancer; 60% of patients with CIN III and 16% with cancer showed reactivity for TGF- β1. High intensity of p16^CDKN2A reactivity and low intensity of TGF- β1 reactivity were observed.

CONCLUSIONS

The linear frequency of p16^CDKN2A expression accompanied by decreased frequency of TGF- β1 in CIN III and cancer could be involved in the neoplasia progression.

HPV infection and p16INK4A and TP53 expression in rare cancers of the uterine cervix

Cervix cancer remains among most commonly diagnosed cancer in developing countries. Except squamous cell carcinoma and adenocarcinoma, the etiopathology and oncogenic mechanisms of rare cancers remain largely unknown. The study was performed to investigate the value of HPV infection and the expression of p16^INK4A and TP53 in rare primitive cancers of the cervix. We conducted a retrospective study of rare primitive cancers of the cervix. Main clinicopathological features were reported. HPV infection was detected by in situ hybridization. Expression of p16^INK4A and TP53 was analyzed by immunohistochemistry. Overall, seven cases were identified, including basaloid squamous cell carcinoma (BSCC, n = 2), small cell neuroendocrine carcinoma (SCNEC), granulocytic sarcoma without acute myeloid leukemia, leiomyosarcoma, primitive neuroectodermal tumor and botryoid-type embryonic rhabdomyosarcoma. The mean age of patients was 53.7 years. Four cancers were diagnosed at advanced stages. The prognosis was unfavorable and associated with patient death in five cases. HPV types 16/18 were detected in BSCCs and SCNEC. Strong and diffuse p16^INK4A overexpression was described in the nucleus and the cytoplasm of all tumor cells of BSCCs and SCNEC. The remaining cancers exhibited only scattered and focal p16^INK4A staining. Mutated TP53 protein was detected in BSCC (case 1) and GS. Rare cancers of the cervix are aggressive and associated with poor prognosis. In contrast to mesenchymal tumors, BSCCs and SCNEC are etiologically related to high-risk HPV infection and could be identified by block positive p16^INK4A overexpression as common cancers of the cervix. TP53 mutations are not a negligible genetic event in rare cervical cancers.

Immunohistochemical expression of p16, Ki-67 and p53 in cervical lesions - A systematic review

This study evaluated the immunohistochemical (IHC) expression of p16, p53 and Ki-67 in precancerous lesions and in cervical cancer (CC). Identification and review of publications assessing IHC expression in cervical intraepithelial neoplasia (CIN) and CC until February 15, 2017. Systematic review of studies in women with and without cervical lesions in order to evaluate whether there is overexpression of these biomarkers. A total of 28 publications met the criteria which included 6005 patients. The analysis showed that there is higher IHC expression of these biomarkers associated with the more severe lesions. Nineteen out of 22 evaluated studies have shown that there is a higher p16 expression in more severe lesions (CC), while in p53 expression only 4 out of the 9 studies showed a higher expression among more severe cases. Regarding the Ki-67 expression, it was observed that 9 out of 14 studies showed higher expression in more severe lesions. A complete absence of or just minimal IHC expression was observed in the normal cervical epithelium, whilst a significant increase in the expression of these biomarkers was detected according to the severity of lesions. Results suggest that these biomarkers can be considered useful tools for discriminating between the stages of the progressive cervical disease.

p16INK4A expression in squamous cell carcinomas of the vagina and the vulva in Tunisian women

BACKGROUND

The role of p16INK4A expression in uterine cervix cancer is well established. In the remaining female lower genital tract cancers, the importance of p16INK4A up-regulation is less clear. In our study, we analyzed the role of p16INK4A expression and HPV infection in carcinomas of the vulva and the vagina in Tunisian women.

MATERIALS AND METHODS

We conducted a retrospective study of 30 carcinomas including 15 vulvar squamous cell carcinomas (SCCs) and 15 vaginal SCCs. Immunohistochemistry was used to determine p16INK4A expression. HPV detection and typing was by in situ hybridization.

RESULTS

p16INK4A expression was detected in 86.7% of vaginal SCCs with a strong and diffuse immunostaining in 60% of cases, and also in 73.3% of vulvar SCCs with focal immunoreactivity in 53.3% The association between p16INK4A expression and HPV infection was significant in vaginal SCCs (p=0.001) but not vulvar SCCs (p>0.05).

CONCLUSIONS

p16INK4A expression could be used as a useful marker for HPV positivity in vaginal SCCs similar to that described in uterine cervix cancers. However, our data support the presence of 2 different mechanisms for p16INK4A expression in HPV-related and HPV-unrelated vulvar carcinomas.

p16 expression in patients with cervical cancer and its prognostic significance: meta-analysis of published literature

OBJECTIVES

p16, a tumour suppressor, is unable to express its suppressive effects following interaction with E7-retinoblastoma protein. Previous reports have suggested that p16 immunostaining allows precise identification of cervical intra-epithelial neoplasia and cervical cancer lesions in biopsies. The prognostic value of p16 expression in cervical cancers has been evaluated for several years, but the results remain controversial. As such, the authors undertook a systematic review and meta-analysis of studies assessing the impact of p16 expression on overall survival and disease-free survival.

STUDY DESIGN

Medline, Embase and China National Knowledge Infrastructures were searched to identify studies on the prognostic impact of p16 expression in patients with cervical cancer. In total, 1070 patients from 10 eligible studies were included in the analysis. Pooled risk ratios (RRs) with 95% confidence intervals (95% CI) were calculated.

RESULTS

A significant association was found between p16 expression and increased disease-free survival (RR 0.60; 95% CI 0.44-0.82; p=0.001). However, no significant association was found between p16 and overall survival.

CONCLUSION

p16 expression may be predictive of a favourable prognosis in patients with cervical cancer. However, large-scale, multicentre and well-matched cohort studies are warranted to confirm this finding.

P16(INK4A) immunostaining is a strong indicator for high-risk-HPV-associated oropharyngeal carcinomas and dysplasias, but is unreliable to predict low-risk-HPV-infection in head and neck papillomas and laryngeal dysplasias

Human papillomavirus (HPV) is a risk factor for the development of benign and malignant mucosal head and neck lesions. P16(INK4A) is often used as a surrogate marker for HPV-infection, although there is still controversy with respect its reliability. Our aim was to determine if p16(INK4A) overexpression can accurately predict both high-risk and low-risk-HPV-presence in (pre)malignant and benign head and neck lesions. P16(INK4A) immunohistochemistry was performed on paraffin-embedded tissue sections of 162 oropharyngeal squamous cell carcinomas (OPSCC), 14 tonsillar and 23 laryngeal dysplasias, and 20 tonsillar and 27 laryngeal papillomas. PCR, enzyme-immunoassay and FISH analysis were used to assess HPV-presence and type. Of the 162 OPSCC and 14 tonsillar dysplasias, 51 (31%) and 10 (71%) were HPV16-positive, respectively. All tonsillar papillomas were HPV-negative and four laryngeal dysplasias and 26 laryngeal papillomas were positive for HPV6 or -11. P16(INK4A) immunohistochemistry revealed a strong nuclear and cytoplasmic staining in 50 out of 51 HPV16-positive and 5 out of 111 HPV-negative OPSCC (p < 0.0001) and in all HPV16-positive tonsillar dysplasias, whereas highly variable staining patterns were detected in the papillomas and laryngeal dysplasias, irrespective of the HPV-status. In addition, the latter lesions generally showed a higher nuclear than cytoplasmic p16(INK4A) immunostaining intensity. In conclusion, our data show that strong nuclear and cytoplasmic p16(INK4A) overexpression is a reliable surrogate indicator for HPV16 in OPSCC and (adjacent) dysplasias. For HPV6 or -11-positive and HPV-negative benign and premalignant lesions of the tonsil and larynx, however, p16(INK4A) immunostaining is highly variable and cannot be recommended to predict HPV-presence.

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.

p16(INK4a) is a useful marker of human papillomavirus integration allowing risk stratification for cervical malignancies

The present study was conducted to assess utility of p16(INK4a) immunopositivity as a surrogate marker for genomic integration of high-risk human papillomavirus infection (hrHPV). A total of 29 formalin-fixed, paraffin-embedded cervical low-grade squamous intraepithelial lesions (LSILs), 27 high-grade squamous intraepithelial lesions (HSILs) and 53 invasive squamous cell carcinomas (SCCs), histologically-diagnosed between 1st January 2006 to 31st December 2008 at the University of Malaya Medical Centre were stained for p16(INK4a) (CINtec Histology Kit (REF 9511, mtm laboratories AG, Heidelberg, Germany). Immunopositvity was defined as diffuse staining of the squamous cell cytoplasm and or nucleus (involving > 75% of the intraepithelial lesions or SCCs). Staining of basal and parabasal layers of intraepithelial lesions was pre-requisite. One (3.4%) LSIL, 24 (88.9%) HSIL and 46 (86.8%) SCC were p16(INK4a) immunopositive. All normal squamous epithelium did not express p16(INK4). p16(INK4a) expression was significantly lower (p<0.05) in LSIL compared with HSIL and SCC with no difference in expression between HSIL and SCC.The increased p16(INK4a) immunopositivity in HSIL and SCC appears in line with the integrated existence of the hrHPV and may provide more insightful information on risk of malignant transformation of cervical squamous intraepithelial lesions than mere hrHPV detection.

Epigenetic alterations in preneoplastic and neoplastic lesions of the cervix

Cervical cancer (CC) is one of the most malignant tumors and the second or third most common type of cancer in women worldwide. The association between human papillomavirus (HPV) and CC is widely known and accepted (99.7% of cases). At present, the pathogenesis mechanisms of CC are not entirely clear. It has been shown that inactivation of tumor suppressor genes and activation of oncogenes play a significant role in carcinogenesis, caused by the genetic and epigenetic alterations. In the past, it was generally thought that genetic mutation was a key event of tumor pathogenesis, especially somatic mutation of tumor suppressor genes. With deeper understanding of tumors in recent years, increasing evidence has shown that epigenetic silencing of those genes, as a result of aberrant hypermethylation of CpG islands in promoters and histone modification, is essential to carcinogenesis and metastasis. The term epigenetics refers to heritable changes in gene expression caused by regulation mechanisms, other than changes in DNA sequence. Specific epigenetic processes include DNA methylation, chromotin remodeling, histone modification, and microRNA regulations. These alterations, in combination or individually, make it possible to establish the methylation profiles, histone modification maps, and expression profiles characteristic of this pathology, which become useful tools for screening, early detection, or prognostic markers in cervical cancer. This paper reviews recent epigenetics research progress in the CC study, and tries to depict the relationships between CC and DNA methylation, histone modification, as well as microRNA regulations.

Promoter hypermethylation of CDH13, DAPK1 and TWIST1 genes in precancerous and cancerous lesions of the uterine cervix

Aberrant DNA methylation is an early event in carcinogenesis and could serve as an additional molecular marker for the early diagnosis. The study was performed to investigate the promoter methylation of DAPK1, CDH13, and TWIST1 genes in uterine cervix lesions in an effort to examine whether this epigenetic event is involved in the process of cervical carcinogenesis, and whether it might be used as a molecular marker of cervical lesions. We conducted a retrospective study of 60 uterine cervix specimens, including 8 normal tissue samples, 10 benign lesions, 28 precancerous lesions (CIN1-3), and 14 squamous cell carcinomas (SCC). DNA hypermethylation was investigated using methylation-specific PCR. Immunohistochemistry was used to find p16(INK4A) overexpression. No hypermethylated promoters were detected in normal tissues and benign lesions. However, promoter hypermethylation of CDH13, TWIST1, and DAPK1 increased progressively from CIN1 to cancer, reaching values higher than 50% for cancer. DAPK1 and CDH13 displayed a significantly increased frequency of promoter methylation with progressively more severe cervical neoplasia (p<0.05). A statistically significant association was observed between p16(INK4A) expression and hypermethylation of DAPK1, TWIST1, and CDH13 (p<0.0001). Hypermethylation of CDH13, DAPK1, and TWIST1 promoters is an early event in the initiation and progression of cervix neoplasia. CDH13, DAPK1, and TWIST1 genes are potential biomarkers of cervical cancer risk.