Amplification of the chromosome 3q26 region shows high negative predictive value for nonmalignant transformation of LSIL cytologic finding

Emerging biomarkers and clinical significance of HPV genotyping in prevention and management of cervical cancer

Cervical cancer is a growing and serious problem world-wide in women, but more acute in developing countries especially in Indian subcontinent. The main causative agent for the disease is Human Papilloma Virus (HPV). The history of the cervical cancer goes back to eighteenth century as the HPV infection is reported since 1800s. Presently, the genetic structure of HPV is well defined. Several screening tests including cytology and visual based screening and high risk HPV testing are available. Also available are various clinical and commercial diagnostic tests. However due to the lack of awareness and population-based screening programs, the morbidity and mortality rate is alarmingly high. There are new emerging biomarkers including E6/E7 mRNA, p16^ink4a, markers of aberrant S-phase induction, chromosomal abnormalities and miRNAs along with advanced genotyping methods. These markers have clinical significance and are helpful in disease prevention and management. Further, recent advancement in the field of metagenomics has increased the prospects of identifying newer microbes, viruses hitherto reported thus far in the context of HPV infection. Analysis of HPV cases using modern tools including genotyping using more powerful biomarkers is envisaged to enhance the prospects of early diagnosis, better prognosis, more reliable treatment and eventual management of the disease.

Gain of Chromosomal Region 3q26 as a Prognostic Biomarker for High-Grade Cervical Intraepithelial Neoplasia: Literature Overview and Pilot Study

Approximately 20–40% of high-grade Cervical Intraepithelial Neoplasia (CIN) regresses spontaneously, but the natural prognosis of an individual lesion is unpredictable. Gain of the chromosomal 3q region, which contains the human telomerase RNA gene on 3q26, is found in CIN lesions and cervical carcinoma and shows correlation with disease grade. The aim of this study is to assess whether 3q26 gain as a single genetic marker can predict the natural prognosis of high-grade CIN, by performing a review of the literature and pilot study. A literature review was conducted. Additionally, we performed a pilot study in 19 patients with histologically confirmed high-grade CIN lesions who were followed for a mean of 115 days, after which loop excision was performed. Fluorescent in situ hybridization analysis was performed on the initial diagnostic biopsies to determine gain of 3q26. Eight studies were included in the literature overview, with a total of 407 patients. Of these, only 22 patients had high-grade lesions. All studies found an association between 3q26 gain and disease prognosis. Positive predictive values (PPV) ranged from 50 to 93%, negative predictive values (NPV) ranged from 75 to 100%. Only five out of 155 patients (3.2%) without 3q26 gain showed disease persistence or progression. In our pilot study on 3q26 gain in high-grade CIN, the PPV of 3q26 gain for disease persistence was 67%, the NPV 100%. All four patients without 3q26 gain showed disease regression. In conclusion, the absence of 3q26 gain in diagnostic biopsies may be applied to identify high-grade CIN lesions with a high probability of disease regression.

Triage of high-risk HPV positive women in cervical cancer screening

INTRODUCTION

High-risk human papillomavirus (hrHPV) testing is expected to replace cytology as primary screening method for cervical cancer screening in an increasing number of countries. The high sensitivity of hrHPV testing is combined with a limited specificity which makes triaging of hrHPV positive women necessary. As an ideal triage method does not yet exist, an optimal triage strategy for hrHPV positive women based on current knowledge should be obtained. The aim of this article is to present an overview of available options for triage of hrHPV positive women, with their strengths and limitations and possible future opportunities.

AREAS COVERED

Current knowledge on morphological biomarkers, molecular biomarkers and combined triage strategies will be discussed to give an overview of the state-of-the-art on triaging hrHPV positive women. The literature search was limited to studies on triage strategies for hrHPV positive women. Expert commentary: Experience with morphology-based biomarkers makes these a valuable triage method. However, they lack the ability of differentiating productive from transforming infections. Molecular biomarkers are objective, highly reproducible, can be used in high throughput testing, and show promising results. With more extensive knowledge on these molecular markers, cervical cancer screening may transform to a full molecular screening in the future.

Identification of SEC62 as a potential marker for 3q amplification and cellular migration in dysplastic cervical lesions

Background

Chromosome 3 amplification affecting the 3q26 region is a common genomic alteration in cervical cancer, typically marking the transition of precancerous intraepithelial lesions to an invasive phenotype. Though potential 3q encoded target genes of this amplification have been identified, a functional correlation of potential oncogenic function is still missing. In this study, we investigated copy number changes and the expression level of SEC62 encoded at 3q26.2 as a new potential 3q oncogene in dysplastic cervical lesions and analyzed its role in cervical cancer cell biology.

Methods

Expression levels of Sec62 and vimentin were analyzed in liquid based cytology specimens from 107 women with varying grades of cervical dysplasia ranging from normal cases to cancer by immunofluorescence cytology. Additionally, a subset of 20 representative cases was used for FISH analyses targeting SEC62. To further explore the functional role of Sec62 in cervical cancer, HeLa cells were transfected with a SEC62 plasmid or SEC62 siRNA and analyzed for their proliferation and migration potential using real-time monitoring and trans-well systems as well as changes in the expression of EMT markers.

Results

FISH analyses of the swabbed cells showed a rising number of SEC62 gains and amplifications correlating to the grade of dysplasia with the highest incidence in high grade squamous intraepithelial lesions and squamous cell carcinomas. When analyzing the expression level of Sec62 and vimentin, we found a gradually increasing expression level of both proteins according to the severity of the dysplasia. In functional analyses, SEC62 silencing inhibited and SEC62 overexpression stimulated the migration of HeLa cells with only marginal effects on cell proliferation, the expression level of EMT markers and the cytoskeleton structure.

Conclusions

Our study suggests SEC62 as a target gene of 3q26 amplification and a stimulator of cellular migration in dysplastic cervical lesions. Hence, SEC62 could serve as a potential marker for 3q amplification, providing useful information about the dignity and biology of dysplastic cervical lesions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2739-6) contains supplementary material, which is available to authorized users.

Human Papillomavirus Laboratory Testing: the Changing Paradigm

High-risk human papillomaviruses (HPVs) cause essentially all cervical cancers, most anal and oropharyngeal cancers, and some vaginal, vulvar, and penile cancers. Improved understanding of the pathogenesis of infection and the availability of newer tests are changing the approach to screening and diagnosis. Molecular tests to detect DNA from the most common high-risk HPVs are FDA approved for use in conjunction with cytology in cervical cancer screening programs. More-specific tests that detect RNA from high-risk HPV types are now also available. The use of molecular tests as the primary screening tests is being adopted in some areas. Genotyping to identify HPV16 and -18 has a recommended role in triaging patients for colposcopy who are high-risk HPV positive but have normal cytology. There are currently no recommended screening methods for anal, vulvar, vaginal, penile, or oropharyngeal HPV infections. HPV testing has limited utility in patients at high risk for anal cancer, but p16 immunohistochemistry is recommended to clarify lesions in tissue biopsy specimens that show moderate dysplasia or precancer mimics. HPV testing is recommended for oropharyngeal squamous cell tumors as a prognostic indicator. Ongoing research will help to improve the content of future guidelines for screening and diagnostic testing.

c-myc copy number gain is a powerful prognosticator of disease outcome in cervical dysplasia

Cervical carcinoma develops from preneoplasia by a multistep process. Although most low-grade dysplastic lesions will regress without intervention and even high-grade changes exhibit a substantial rate of regression, a small percentage of dysplasia will progress over time. Thus, indicators are needed to estimate the biological risk and to help avoid overtreatment in women who desire to preserve fertility. In addition to the classical biomarkers, PCR-ELISA-determined HPV genotype and immunohistochemically assessed p16^INK4a and Ki-67 expression, cells with integrated HPV and copy number gain of TERC and c-myc were quantified in a panel of 104 benign, intraepithelial neoplastic (CIN I, II, III) and cancerous lesions using fluorescence in situ hybridization. Optimal cut-off values were calculated; Kaplan-Meier curves and a Cox proportional hazard regression model were used to evaluate prognostic signatures. The assay reliably identified HPV integration, TERC and c-myc copy number gain as determined by comparisons with established biomarkers. All biomarker levels increased with the progression of the disease. However, only c-myc copy number gain independently prognosticated a low probability of dysplastic regression. Our results suggest that c-myc plays a key role in the process of dysplastic transformation and might thus be exploited for treatment and follow-up decision-making of cervical dysplasia.

Clinical Role of the Detection of Human Telomerase RNA Component Gene Amplification by Fluorescence in situ Hybridization on Liquid-Based Cervical Samples: Comparison with Human Papillomavirus-DNA Testing and Histopathology

OBJECTIVE

This study was designed to evaluate whether the adjunct of human telomerase RNA component (hTERC) fluorescence in situ hybridization (FISH) analysis to cytological diagnosis and human papillomavirus (HPV)-DNA testing may serve as a predictive marker for distinguishing cervical lesions destined to regress from those at high risk of progression towards invasive cancer.

STUDY DESIGN

hTERC FISH analysis was performed on 54 residual liquid-based cytology specimens obtained from women referred to colposcopy for the detection of atypical squamous cells of undetermined significance or worse (ASCUS+) lesions. Histological diagnosis was considered the gold standard and cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) as the worst outcome.

RESULTS

Oncogenic HPV-DNA was found in 96.3% of the specimens. Among these, 38.5% revealed a CIN2+ diagnosis. hTERC gene amplification was detected in 37% of the cases; among these, 70% showed up as CIN2+. hTERC FISH analysis significantly improves the specificity and positive predictive value of HPV-DNA testing, thus differentiating patients with a CIN2+ diagnosis from those with a CIN2- diagnosis.

CONCLUSIONS

Despite the limitation of a small study sample, our findings provide promising data, indicating the possible role of hTERC analysis in the assessment of the risk of developing cervical cancer. This approach would implement the specificity of DNA testing, avoiding overtreatment at the same time. Prospective follow-up studies are needed with the aim of introducing hTERC FISH into decision-making algorithms.

Amplification of the 3q chromosomal region as a specific marker in cervical cancer

OBJECTIVE

Chromosome 3q gain has been consistently observed in cervical intraepithelial neoplasia grades 2 and 3 (CIN 2,3) and squamous cell carcinomas of the cervix. There are a number of potential clinical uses of testing for 3q gain in liquid cytology specimens, including the identification of subsets of women with atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion cytology who are at greatest risk of having CIN 2,3 and would thus benefit most from immediate colposcopy. The objective of this study was to establish the sensitivity and specificity of 3q gain for discriminating between CIN 2,3 and normal.

STUDY DESIGN

Residual cytology specimens were collected from 199 women. Liquid-based cytology (LBC) was used for the selection of subjects, with women with high-grade squamous intraepithelial lesion or high-grade squamous intraepithelial lesion who had colposcopy and adjudicated biopsy-confirmed CIN 2,3 forming the disease-positive group (n = 28) and women doubly negative for both cytology and high-risk human papillomavirus (hrHPV) testing forming the disease-negative group (n = 171). A single slide was prepared from each residual LBC specimen and analyzed for 3q gain by fluorescent in situ hybridization, using a probe specific for the 3q26 region and a control probe for the chromosome 7 centromere. Two approaches were compared for the determination of 3q gain. The first was based on the analysis of an entire cervical cytology slide for the presence of rare cells with a high copy number (>4 copies) for the 3q locus. The second approach was based on the analysis of 400 cells to determine the percentage with 3 or more copies of the 3q locus.

RESULTS

Using the approach based on the detection of rare cells with a high copy number (>4 copies) for the 3q locus, 26 of the specimens from women with CIN 2,3 and none of the 171 specimens from women who were both hrHPV and cytology negative was positive for 3q gain. This translates to a sensitivity of 92.9% (95% confidence interval [CI], 76.5-98.9%), a specificity of 100% (95% CI, 97.8-100%), a positive predictive value of 100% (95% CI, 86.7-100%), and a negative predictive value of 98.8% (95% CI, 95.9-99.8), for distinguishing CIN 2,3 from normal.

CONCLUSION

These data support the potential clinical use of 3q gain for the evaluation of women in a number of clinical situations, including women with atypical squamous cells of undetermined significance, low-grade squamous intraepithelial lesion, and those who are hrHPV positive.

Is there a gain in chromosome 3q in the pathway to anal cancer?

BACKGROUND

Chromosome 3q gain has been identified in human papillomavirus-infected cervical cancer cells.

OBJECTIVE

We sought to identify the presence of chromosomal 3q gain in anal neoplasia.

DESIGN

This was a retrospective cohort.

SETTINGS

The study was conducted in a group colorectal surgery practice.

PATIENTS

Fifty-two patients with no dysplasia, low-grade dysplasia, high-grade dysplasia, or anal cancer were studied.

INTERVENTIONS

Pairs of biopsy specimens were paraffin embedded and reviewed. One of each slide pair was stained with hematoxylin and eosin and the second processed for fluorescence in situ hybridization. The hybridized set was deparaffinized first and then hybridized with a probe for the chromosome 3q26 region. Then, slides were scanned using an automated fluorescence microscopy system that analyzed defined areas of the tissue to enumerate all of the nuclei for hybridized probe signals to detect chromosome 3q gain.

MAIN OUTCOME MEASURES

We measured for gain in chromosome 3q26.

RESULTS

We identified chromosome 3q gain in 7 (78%) of 9 patients with squamous-cell cancer, 8 (53%) of 15 high-grade dysplasia samples, 0 of 12 low-grade dysplasia samples, and 0 of 16 samples with no dysplasia. The sensitivity for high-grade or invasive neoplasia was 58%, with a specificity of 100%. The positive predictive value of the test was 100% for detecting high-grade dysplasia and/or squamous-cell cancer from no dysplasia, and the negative predictive value of the test was 62%.

LIMITATIONS

This study was limited by its small sample size and retrospective design.

CONCLUSIONS

Chromosome 3q gain represents an important shared pathway to tumorigenesis in cervical and anal neoplasia. Multiple potential diagnostic roles exist for this easily performed test in the evaluation of anal neoplasia.

Methylated ZNF582 gene as a marker for triage of women with Pap smear reporting low-grade squamous intraepithelial lesions - a Taiwanese Gynecologic Oncology Group (TGOG) study

OBJECTIVE

Our previous work revealed that host genes ZNF582, PTPRR, PAX1, and SOX1 are highly methylated in cervical intraepithelial neoplasias grade 3 or worse (CIN3(+)). In this study, we used a standardized testing assay to evaluate the clinical efficacy of these biomarkers in the triage of cytological diagnoses of low-grade squamous intraepithelial lesions (LSILs), and compared the performance with human papillomavirus (HPV) testing.

METHODS

This 2-year multicenter prospective study examined a population of 230 women from 12 medical centers who were diagnosed with LSILs on cervical cytology. Cervical scrapings were obtained prior to a colposcopy-directed biopsy for quantitative methylation analysis of ZNF582, PTPRR, PAX1, and SOX1, and HPV testing. Using logistic regression and receiver operating characteristic curve analyses, the abilities of methylated genes and HPV to predict CIN3(+) were assessed.

RESULTS

Fifteen (6.5%) of the 230 women with a cytological diagnosis of LSIL were confirmed to have CIN3(+) after a colposcopy-directed biopsy. Among the 4 methylated genes, ZNF582 was found to be the best biomarker for detecting CIN3(+). The sensitivities for methylated ZNF582 and HPV testing were 73% and 80%, and the specificities were 71% and 28%, respectively. The odds ratio for predicting CIN3(+) using methylated ZNF582 was 6.8 (95% confidence interval (CI) 2.1-22.1), which was much better than HPV testing (OR=1.6, 95% CI 0.4-5.8).

CONCLUSION

This is the first study to show that ZNF582 methylation analysis of cervical swabs may be a promising choice in the positive triage of cytological diagnoses of LSILs.

Molecular targets of HPV oncoproteins: potential biomarkers for cervical carcinogenesis

Cervical cancer is the second most common cancer among women worldwide and is responsible for 275,000 deaths each year. Persistent infection with high-risk human papillomavirus (HR-HPV) is an essential factor for the development of cervical cancer. Although the process is not fully understood, molecular mechanisms caused by HPV infection are necessary for its development and reveal a large number of potential biomarkers for diagnosis and prognosis. These molecules are host genes and/or proteins, and cellular microRNAs involved in cell cycle regulation that result from disturbed expression of HR-HPV E5, E6 and E7 oncoproteins. One of the current challenges in medicine is to discover potent biomarkers that can correctly diagnose cervical premalignant lesions and standardize clinical management. Currently, studies are showing that some of these molecules are potential biomarkers of cervical carcinogenesis, and it is possible to carry out a more accurate diagnosis and provide more appropriate follow-up treatment for women with cervical dysplasia. In this paper, we review recent research studies on cell cycle molecules deregulated by HPV infections, as well as their potential use for cervical cancer screening.

Chromosomal gains measured in cytology samples from women with abnormal cervical cancer screening results

OBJECTIVE

Chromosomal gains at 3q26, 5p15 and 20q13 have been described in cervical precancer and cancer. We evaluated a novel fluorescence in situ hybridization (FISH) assay that detects gains at these three loci simultaneously as a possible biomarker for detecting cervical precancer.

METHODS

Chromosomal copy numbers at 3q26, 5p15, 20q13 and the centromere of chromosome7 (cen7) in liquid-based cytology specimens from 168 women enrolled in the Biopsy Study were determined by FISH. The number of cells with ≥ 3 or ≥ 4 signals for a genomic locus was enumerated and diagnostic test performance measures were calculated using receiver operating characteristic (ROC) analyses. Sensitivity and specificity values were determined for the detection of CIN2+ and/or HSIL.

RESULTS

The median number of cells with ≥ 3 signals increased with the severity of cervical lesion for each genomic locus (p-trend<0.02 for each locus). ROC analysis for the number of cells with ≥ 3 signals resulted in area under the curve values of 0.70 (95% CI: 0.54-0.86), 0.67 (0.52-0.83), 0.67 (0.51-0.83) and 0.78 (0.64-0.92) for 3q26, 5p15, 20q13 and cen7, respectively, for the detection of CIN2+ and/or HSIL. Positivity for gains at multiple loci resulted in only slightly better test performance measures than those for the individual probes for four distinct combinations of probes.

CONCLUSIONS

Chromosomal gains at 3q26, 5p15, 20q13 and cen7 are associated with severity of cervical lesions. Further studies are required to quantify risk stratification of FISH assays for cervical cancer screening.

3q26 amplification is an effective negative triage test for LSIL: a historical prospective study

Background

Women with low grade squamous intraepithelial lesions (LSIL) at cervical cancer screening are currently referred for further diagnostic work up despite 80% having no precancerous lesion. The primary purpose of this study is to measure the test characteristics of 3q26 chromosome gain (3q26 gain) as a host marker of carcinogenesis in women with LSIL. A negative triage test may allow these women to be followed by cytology alone without immediate referral to colposcopy.

Methods and Findings

A historical prospective study was designed to measure 3q26 gain from the archived liquid cytology specimens diagnosed as LSIL among women attending colposcopy between 2007 and 2009. 3q26 gain was assessed on the index liquid sample; and sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were measured at immediate triage and at 6–16 months after colposcopic biopsy. The sensitivity of 3q26 gain measured at immediate triage from automated and manually reviewed tests in 65 non-pregnant unique women was 70% (95% CI: 35, 93) with a NPV of 89% (95% CI: 78, 96). The sensitivity and NPV increased to 80% (95% CI: 28, 99) and 98% (95% CI: 87, 100), respectively, when only the automated method of detecting 3q26 gain was used.

Conclusions

3q26 gain demonstrates high sensitivity and NPV as a negative triage test for women with LSIL, allowing possible guideline changes to routine surveillance instead of immediate colposcopy. Prospective studies are ongoing to establish the sensitivity, specificity, PPV and NPV of 3q26 gain for LSIL over time.

Sec62 bridges the gap from 3q amplification to molecular cell biology in non-small cell lung cancer

The molecular carcinogenesis of lung cancer has yet to be clearly elucidated. We investigated the possible oncogenic function of SEC62 in lung cancer, which was predicted based on our previous findings that lung and thyroid cancer tissue samples exhibited increased Sec62 protein levels. The SEC62 gene locus is at 3q26.2, and 3q amplification is reportedly the most common genomic alteration in non-small cell lung cancer. We analyzed SEC62 mRNA and protein levels in tissue samples from lung cancer patients by real-time quantitative PCR, Western blot, and IHC and found significantly increased SEC62 mRNA and protein levels in tumors compared with tumor-free tissue samples from the same patients. Correlation analyses revealed significantly higher Sec62 levels in tumors with lymph node metastases compared with nonmetastatic tumors, as well as in poorly compared with moderately differentiated tumors. On the basis of these promising results, we examined the role of Sec62 in cancer cell biology in vitro. Cell migration assays with lung and thyroid cancer cells showed distinct stimulation of migration in SEC62-overexpressing cells and inhibition of migration in Sec62-depleted cells. Moreover, we found that SEC62 silencing sensitized the cells to thapsigargin-induced endoplasmic reticulum stress. Thus, our results indicate that SEC62 represents a potential candidate oncogene in the amplified 3q region in cases of non-small cell lung cancer and harbors various functions in cancer cell biology.

Human papillomavirus and cervical cancer: biomarkers for improved prevention efforts

While organized screening programs in industrialized countries have significantly reduced cervical cancer incidence, cytology-based screening has several limitations. Equivocal or mildly abnormal Pap tests require costly retesting or diagnostic work-up by colposcopy and biopsy. In low-resource countries, it has been difficult to establish and sustain cytology-based programs. Advances in understanding human papillomavirus biology and the natural history of human papillomavirus-related precancers and cancers have led to the discovery of a range of novel biomarkers in the past decade. In this article, we will discuss the potential role of new biomarkers for primary screening, triage and diagnosis in high-resource countries and their promise for prevention efforts in resource constrained settings.

Detection of TERC amplification in cervical epithelial cells for the diagnosis of high-grade cervical lesions and invasive cancer: a multicenter study in China

Because the activation of telomerase is a relatively early event in the progression of cervical carcinogenesis, the expression of the human telomerase RNA gene, TERC, has the potential to serve as a biomarker for both the diagnosis and prognosis of cervical neoplasias. In total, 83 research centers participated in the study, and 7786 patients were enrolled. TERC amplification was detected using a dual-color fluorescence in situ hybridization (FISH) probe set, and these results were compared with cytological and histological results, testing for high-risk human papillomavirus (HPV) DNA (n = 2316 for the HPV DNA test), as well as patient age. TERC amplification was found to be increased in more advanced cases of cervical carcinogenesis. Moreover, a Youden's index value and the area under the receiver operating characteristic (ROC) curve were also calculated for samples with TERC amplification and found to be higher than the same values calculated for both cytology and high-risk HPV analyses of the same samples. With regard to cytological ASCUS and LSIL findings, the combination of HPV + TERC testing showed the potential to provide effective triaging to detect CIN2(+). Therefore, TERC amplification represents a valuable genetic biomarker, which in combination with an evaluation of cytology or HPV testing, can achieve higher sensitivity and specificity in distinguishing high-grade cervical lesions and invasive cancers from low-grade lesions compared with conventional methods.