What is the role of HPV typing in the United States now and in the next five years in a vaccinated population?

Cervical cancer risk profiling: molecular biomarkers predicting the outcome of hrHPV infection

INTRODUCTION

Cervical cancer affects half a million women worldwide annually. Given the association between high-risk human papillomavirus (hrHPV) infection and carcinogenesis, hrHPV DNA testing became an essential diagnostic tool. However, hrHPV alone does not cause the disease, and, most importantly, many cervical lesions regress to normal in a year because of the host immune system. Hence, the low specificity of hrHPV DNA tests and their inability to predict the outcome of infections have triggered a further search for biomarkers.

AREAS COVERED

We evaluated the latest viral and cellular biomarkers validated for clinical use as primary screening or triage for cervical cancer and assessed their promise for prevention as well as potential use in the future. The literature search focused on effective biomarkers for different stages of the disease, aiming to determine their significance in predicting the outcome of hrHPV infections.

EXPERT OPINION

Biomarkers such as p16/Ki-67, hrHPV genotyping, hrHPV transcriptional status, and methylation patterns have demonstrated promising results. Their eventual implementation in the screening programs may support the prompt diagnosis of hrHPV infection and its progression to cancer. These biomarkers will help in making clinical management decisions on time, thus, saving the lives of hrHPV-infected women, particularly in developing countries.

Comparison of Analytical and Clinical Performance of HPV 9G DNA Chip, PANArray HPV Genotyping Chip, and Hybrid-Capture II Assay in Cervicovaginal Swabs

Background:

Human papillomavirus (HPV) infection can be detected by using several molecular methods, including Hybrid-Capture II (HC2) assay and variable HPV DNA chip tests, although each method has different sensitivities and specificities.

Methods:

We performed HPV 9G DNA Chip (9G) and PANArray HPV Genotyping Chip (PANArray) tests on 118 cervicovaginal swabs and compared the results with HC2, cytology, histology, and direct sequencing results.

Results

The overall and high-risk HPV (HR-HPV) positivity rates were 62.7% and 44.9% using 9G, and 61.0% and 30.5% using PANArray, respectively. The positivity rates for HR-HPV with these two chips were significantly lower than 55.1% when HC2 was used. The sensitivity of overall HPV positivity in detecting histologically confirmed low-grade cervical squamous intraepithelial lesions or higher was 88.7% for all three tests. The specificity was 58.5% for 9G and 61.5% for PANArray, which was significantly lower than the 72.3% for HC2. With the HR-HPV⁺ genotype threshold, the sensitivity decreased to 75.5% for 9G and 52.8% for PANArray, which was significantly lower than the 88.7% for HC2. Comparison of the two chips showed concordant results in 55.1% of the samples, compatible results in 16.9%, and discordant results in 28.0%, exhibiting poor agreement in detecting  certain HPV genotypes. Compared with direct sequencing, 9G yielded no discordant results, whereas PANArray yielded 31 discordant results (26.7%).

Conclusions

Compared with HC2, the HPV genotyping tests showed lower sensitivity in histologic correlation. When the two chips were compared, the 9G was more sensitive and accurate for detecting HR-HPV than the PANArray.

Type- and age-specific distribution of human papillomavirus in women attending cervical cancer screening in Finland

BACKGROUND

Large-scale data on type-specific HPV prevalences and disease burden are needed to monitor the impact of HPV vaccination and to plan for HPV-based cervical screening.

METHODS

33 043 women (aged 25-65) were screened for HPV by a Hybrid Capture 2 (HC2) in a population-based programme. HPV-positive women (n=2574) were triaged by cytology and HPV genotyped using PCR-Luminex. Type-specific prevalence of HPV infection and its correlation to findings in cytology triage and histology as well as Population Attributable Fractions for a referral to colposcopy and findings in histology were calculated.

RESULTS

Among HC2-positive women, 61.5% had normal, 23.1% had ASC-US and 15.5% had LSIL or more severe (LSIL+) results in cytology. Out of HC2-positive samples, 57% contained the 13 Group 1/2A HPV types, which were targeted by the HC2, 15% contained Group 2B types, 8.5% Group 3 types and 30% were found to be negative in HPV genotyping. The proportion of samples positive for HPV by the HC2, but negative in HPV genotyping increased with age and decreased with increasing cytological abnormality. The most frequent types were HPV 16 (0.9% of screened women and 12.1% of the HC2-positive women), HPV 31 (0.7% and 8.9%, respectively) and HPV 52 (0.5% and 6.3%, respectively). The prevalence of Group 1/2A HPV types increased with increasing CIN grade and attributed 78.3% (95% CI 53.4-89.9) of the CIN 3+ lesions, while HPV 16 attributed 55.8% (40.0-67.5) of them.

CONCLUSION

The type-specific prevalence of HPV were slightly lower than the average in international meta-analyses. Genotyping for HPV 16 better identified women with CIN 3+ than cytology triage at the threshold of LSIL+. The high proportion of women that were HC2-positive but HPV-negative in genotyping suggests that HPV genotyping may be useful also for validation of results in HPV screening. The large-scale HPV genotyping data were found to be directly useful for planning further preventive efforts for cervical cancer.

Type-specific prevalence of high-risk human papillomavirus by cervical cytology and age: Data from the health check-ups of 7,014 Korean women

Objective

We investigated the type-specific high-risk human papillomavirus (HPV) prevalence and distribution according to cervical cytology and age in healthy Korean women.

Methods

A retrospective cross-sectional study was conducted with 7,014 consecutive subjects undergoing both liquid-based cervical cytology and HPV genotyping test by DNA chip for cervical cancer screening. The type-specific prevalence and distribution of individual high-risk HPV types were assessed according to cervical cytology and age groups (<30, 30-39, 40-49, 50-59, and ≥60 years old).

Results

In total, the most common HPV genotype was HPV58 (23.9% of all high-risk HPV-positive subjects), followed by HPV16 (21.8%), HPV52 (16.6%), and HPV18 (11.7%). Regarding cervical cytology and age groups, the proportion of HPV56 strongly increased with the increasing severity of cervical cytology (P for trend=0.041). An age-specific decline in the overall high-risk HPV prevalence was reaffirmed, and the proportion of HPV52 declined markedly with age (P for trend=0.014).

Conclusion

The type-specific prevalence of high-risk HPV types significantly varies according to cervical cytology and age. It may imply that these types have different to develop into precancerous lesions in normal cervix.

Near-infrared Raman Microspectroscopy Detects High-risk Human Papillomaviruses

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Cost-effectiveness of using human papillomavirus 16/18 genotype triage in cervical cancer screening

OBJECTIVE

Testing for human papillomavirus (HPV) 16 and 18 genotypes, which are known to cause approximately 65-70% of invasive cervical cancer cases, may allow clinicians to identify women at highest risk for underlying cervical intraepithelial neoplasia missed by Pap cytology. Our objective was to determine the cost-effectiveness of adding HPV-16 and 18 genotype triage to current cervical cancer screening strategies in the United States.

METHODS

We developed a lifetime Markov model to assess the cost-effectiveness of the following cervical cancer screening algorithms: (1) liquid-based cytology (LBC), (2) LBC+HPV triage, (3) HPV+LBC triage, (4) co-screening, (5) co-screening+HPV genotyping, and (6) HPV only+HPV genotyping. Costs were estimated from a payer perspective in 2007 U.S. dollars. Outcome measures included lifetime risk of cervical cancer, quality-adjusted life years saved (QALYs), and incremental cost-effectiveness ratios (ICERs).

RESULTS

In our model, the use of HPV genotyping strategies prevented 51-73 deaths per 100,000 women screened compared to screening using LBC followed by HPV triage and 4-26 deaths compared to co-screening with LBC and high-risk HPV. Use of HPV genotyping to triage all high-risk HPV-positive women every three years had an ICER of $34,074 per QALY compared to HPV and LBC co-screening. HPV genotyping with co-screening was the most effective strategy and had an ICER of $33,807 per QALY compared to HPV genotyping for all high-risk HPV-positive women.

CONCLUSION

The addition of HPV-16 and -18 genotype triage to HPV and LBC co-screening was a cost-effective screening strategy in the United States.