Randomized controlled trial of human papillomavirus testing versus Pap cytology in the primary screening for cervical cancer precursors: Design, methods and preliminary accrual results of the Canadian cervical cancer screening trial (CCCaST)

Implementation of HPV Tests in Latin America: What We Learned; What Should We Have Learned, and What Can We Do Better?

Cervical cancer is caused by HPV. Although it is the fourth most common type of cancer diagnosed and the fourth cause of cancer death, cervical cancer is nearly completely preventable because of the vaccination and screening available. The present review aims to map the initiatives conducted to implement or evaluate the implementation of HPV testing in Latin American countries. We performed the review by searching on PubMed in the English language and on grey literature, as most of the information about the guidelines used was found in governmental websites in the Spanish language. We only found information in eight countries concerning HPV testing as primary screening. Only Mexico has established HPV-based screening in all territories. There are three countries with regional implementation. Two countries with pilot studies indicated results that supported implementation. Finally, there are another two countries with a national recommendation. We have learned that HPV implementation is feasible and a very promising tool for reducing cervical cancer morbidity and mortality. The costs associated with saving lives and reducing suffering due to morbidity of a preventable disease must be pragmatically evaluated by the Latin America governments, and improving outcomes must be a mandatory priority for those that are responsible for addressing an organized system of cervical cancer screening.

Current and future direction in treatment of HPV-related cervical disease

Human papillomavirus (HPV) is the most common sexually transmitted virus in the world. About 70% of cervical cancers are caused by the most oncogenic HPV genotypes of 16 and 18. Since available prophylactic vaccines do not induce immunity in those with established HPV infections, the development of therapeutic HPV vaccines using E6 and E7 oncogenes, or both as the target antigens remains essential. Also, knocking out the E6 and E7 oncogenes in host genome by genome-editing CRISPR/Cas system can result in tumor growth suppression. These methods have shown promising results in both preclinical and clinical trials and can be used for controlling the progression of HPV-related cervical diseases. This comprehensive review will detail the current treatment of HPV-related cervical precancerous and cancerous diseases. We also reviewed the future direction of treatment including different kinds of therapeutic methods and vaccines, genome-editing CRISPR/Cas system being studied in clinical trials. Although the progress in the development of therapeutic HPV vaccine has been slow, encouraging results from recent trials showed vaccine-induced regression in high-grade CIN lesions. CRISPR/Cas genome-editing system is also a promising strategy for HPV cancer therapy. However, its safety and specificity need to be optimized before it is used in clinical setting.

Comparative accuracy of cervical cancer screening strategies in healthy asymptomatic women: a systematic review and network meta-analysis

To compare all available accuracy data on screening strategies for identifying cervical intraepithelial neoplasia grade ≥ 2 in healthy asymptomatic women, we performed a systematic review and network meta-analysis. MEDLINE and EMBASE were searched up to October 2020 for paired-design studies of cytology and testing for high-risk genotypes of human papillomavirus (hrHPV). The methods used included a duplicate assessment of eligibility, double extraction of quantitative data, validity assessment, random-effects network meta-analysis of test accuracy, and GRADE rating. Twenty-seven prospective studies (185,269 subjects) were included. The combination of cytology (atypical squamous cells of undetermined significance or higher grades) and hrHPV testing (excepting genotyping for HPV 16 or 18 [HPV16/18]) with the either-positive criterion (OR rule) was the most sensitive/least specific, whereas the same combination with the both-positive criterion (AND rule) was the most specific/least sensitive. Compared with standalone cytology, non-HPV16/18 hrHPV assays were more sensitive/less specific. Two algorithms proposed for primary cytological testing or primary hrHPV testing were ranked in the middle as more sensitive/less specific than standalone cytology and the AND rule combinations but more specific/less sensitive than standalone hrHPV testing and the OR rule combination. Further research is needed to assess these results in population-relevant outcomes at the program level.

Comparative assessment of test characteristics of cervical cancer screening methods for implementation in low-resource settings

Cervical cancer disproportionately affects low-resource settings. Papanicolaou, human papillomavirus (HPV), and visual inspection of cervix with acetic acid (VIA) testing, each with different characteristics, will reduce cervical cancer burden. We conducted a critical literature review using PubMed, Cochrane, WHO, and grey literature from 1994 to 2020. We examined efficacy, harms, and comparative effectiveness of screening methods by age, human immunodeficiency virus, provider characteristics, and assessed implementation challenges in low-resource settings. Comprehensive data on utility and efficacy of screening tests indicates that each screening has strengths and shortcomings but all confer acceptable performance. HPV and VIA appear more promising. Primary HPV test-and-treat, self-testing, and co-testing have been studied but data on triage plans, cost, support system, implementation and sustainability is unclear in low-resource settings. HPV testing could help target subgroups of older or higher risk women. VIA offers local capacity-building and scalability. Quality VIA technique after HPV testing is still required to guide post-screening treatments. VIA competencies decline gradually with current standard trainings. Stationary cervicography improves VIA quality but isn't scalable. Affordable smartphones eliminate this barrier, enhance training through mentorship, and advance continuing education and peer-to-peer training. Smartphone-based VIA facilitates cervical image storage for patient education, health promotion, record-keeping, follow-up care, remote expert support, and quality control to improve VIA reliability and reproducibility and reduce mis-diagnoses and burden to health systems. Rather than ranking screening methods using test characteristics alone in study or higher-resource settings, we advocate for scalable strategies that maximize reliability and access and reduce cost and human resources.

Digital analysis and quantitative assessment of the cervical surface with dysplasia

The investigation aims - a quantitative assessment of cervical surface changes with digital analysis and computer technologies in dysplasia. Colposcopy was made in 90 women from 21 to 52 years (avr. age 33,9±8,13 y.o.) with mild epithelial dysplasia (CIN1), moderate dysplasia (CIN2), severe dysplasia (CIN3). The algorithm detected indicators which provide the cervical dysplasia classification on pre cytological and pre molecular-genetic patients investigations. The outcome of an algorithm was the identification of the cervix surface condition severity by an objective quantification. The cervical dysplasia type (CIN) was classified as IndGV values. The mild dysplasia (CIN1) had IndGV=8,5, moderate dysplasia (CIN2) - IndGV=13, severe dysplasia (CIN3) - IndGV=15,6. The cervical affected surface area (IndInt) equalled 0,17 in CIN1, 0,19 in CIN2, 0,22 in CIN3. A change severity has a direct relation with a grey color value. It demonstrates quantify classification in digital analysis. The algorithm is used in real-time mode and no requires considerable material outlays. This makes it possible to use an algorithm after clinical examination and predict patient management.

Estimation of diagnostic test accuracy: A "Rule of Three" for data with repeated observations but without a gold standard

This article considers how to estimate the accuracy of a diagnostic test when there are repeated observations, but without the availability of a gold standard or reference test. We identify conditions under which the structure of the observed data is rich enough to provide sufficient degrees of freedom, such that a suitable latent class model can be fitted with identifiable accuracy parameters. We show that a Rule of Three applies, specifying that accuracy can be evaluated as long as there are at least three observations per individual with the given test. This rule also applies if the three observations arise from combinations of different test methods, or from a sequential design in which individuals are tested for a maximum number of times with the same test but stopping if a positive (or negative) result occurs. The rule pertains to tests having an arbitrary number of response categories. Accuracy is evaluated by parameters reflecting rates of misclassification among the response categories, and the model also provides estimates of the underlying distribution of the true disease state. These ideas are illustrated by data from two medical studies. Issues discussed include the advantages and disadvantages of analyzing the response variable as binary or multinomial, as well as the feasibility of testing goodness of fit when the model incorporates a large number of parameters. Comparisons are possible between models that do or do not assume equal accuracy rates for the observations, and between models where certain misclassification parameters are or are not assumed to be zero.

The meaning of high-risk HPV other than type 16/18 in women with negative cytology: Is it really safe to wait for 1 year?

BACKGROUND

Human papillomavirus (HPV) is a primary risk factor for cervical cancer. HPV 16 and 18 are the two most carcinogenic genotypes and have been reported in the majority of cervical cancer. High-risk HPVs (hrHPVs) other than HPV 16/18 cause approximately a quarter of cervical cancers. We aimed to present the colposcopy-guided biopsy results of non-16/18 hrHPV-infected women with negative cytology.

METHODS

This is a retrospective cohort study conducted on 752 patients between the ages of 30-65 years with non-16/18 hrHPV and negative cytology undergoing colposcopy-guided biopsy at a tertiary gynecological cancer center between January-2016 and January-2019.

RESULTS

The mean age of the women was 42.35±9.41 years. Cervical intraepithelial neoplasia (CIN) 2+ lesion was detected in 49 (6.5%) women with negative cytology. The rate of CIN 2+ lesions in women with abnormal cytology was 12.8%. Patients with abnormal cytology had about 2.1 and 2.4 times increased the odds of CIN 2+ lesion in cervical biopsy and endocervical curettage specimens, respectively. CIN 3+ lesion was detected in 20 (2.7%) women with negative cytology. One (0.1%) of the patients with HPV 39 and negative cytology had invasive cervical cancer. The two most common HPV subtypes were HPV 31 and HPV 51.

CONCLUSIONS

The risk of cervical preinvasive lesions still can be detected and cannot be completely eliminated among hrHPV other than 16/18-infected women with negative cytology. Based on the results of this study, referral of non-16/18 hrHPV-infected women with negative cytology to colposcopy is supported as a credible and feasible strategy.

Long-term protection of HPV test in women at risk of cervical cancer

Objective

To evaluate the 9-year incidence of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) and cumulative adherence to perform a next test in a cohort of women aged 40+ years with no cervical screening cytology within a window of 5 years (underscreened women), after baseline cervical cytology and HPV tests.

Methods

In Catalonia, Spain, co-testing with cytology and HPV test has been recommended in the Public Health system since 2006 for underscreened women. In 2007, 1,594 women with underscreened criteria were identified and followed through medical records form Pathological Department. 9-year cumulative incidence of histologically confirmed CIN2+ and cumulative adherence to perform a next test were estimated using Kaplan-Meier statistics.

Results

Follow-up was available for 1,009 women (63.3%) resulting in 23 women with. CIN2+ (2.3%). Of them, 4 women (17%) had both tests negative at baseline (3CIN2 and 1CIN3) with cumulative incidence of CIN2+ of 0.4% (95% CI: 0.1–1.4) at 5-years and 1.3% (95% CI: 0.4–3.7) at 9-years. During the first year, the prevalence among women with both tests positive was 27.0% (95% CI: 13.0–50.6) for CIN2+. Lost to follow-up was higher among women with both tests negative compared to those with both positive tests (38.7% vs 4.2%, p-value <0.001). 40.5% of the women HPV-/cyto- had a re-screening test during the 4 years following the baseline, increasing until 53.5% during the 6 years of follow-up.

Conclusions

HPV detection shows a high longitudinal predictive value at 9-year to identify women at risk to develop CIN2+. The data validate a safe extension of the 3-year screening intervals (current screening interval) to 5-year intervals in underscreened women that had negative HPV result at baseline. It is necessary to establish mechanisms to ensure screening participation and adequate follow-up for these women.

Assessing the time dependence of prognostic values of cytology and human papillomavirus testing in cervical cancer screening

Accurate assessment of risks for developing cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) after a given set of screening test results is instrumental to reaching valid conclusions and informing cervical cancer screening recommendations. Using data from the Canadian Cervical Cancer Screening Trial (CCCaST), we assessed prognostic values of enrollment screening test results to predict CIN2+ among women attending routine cervical screening using multivariable Cox proportional hazards (PH) regression and its flexible extension during each of two follow-up periods (protocol-defined and extended). Nonproportional (time-dependent (TD)) and/or nonlinear effects were modeled, as appropriate. Women with abnormal cytology had hazard ratios (HRs) for CIN2+ detection of 17.61 (95% CI: 11.25-27.57) and 10.46 (95% CI: 5.41-20.24) relative to women with normal cytology during the protocol-defined and extended follow-up periods, respectively. High-risk human papillomavirus (HR-HPV) positivity was an even stronger predictor of CIN2+ risk, with significant TD effects during both follow-up periods (p <0.001 for both TD effects). Risks among women co-testing HR-HPV+ with and without abnormal cytology (relative to women co-testing negative) were highest immediately after baseline, and decreased significantly thereafter (p <0.001 for both TD effects). HRs for HPV16+ and HPV18+ women (relative to those testing HR-HPV-) did not vary significantly over time (HR = 182.96; 95% CI: 95.16-351.77 and HR = 111.81; 95% CI: 44.60-280.31, respectively). Due to TD effects, conventional Cox model estimates considerably underestimated adjusted HRs associated with positive HR-HPV testing results early on in the follow-up periods.

Mega Hpv laboratories for cervical cancer control: Challenges and recommendations from a case study of Turkey

Cervical cancer is the fourth most common cancer among women in the world. It is estimated that one woman dies every 2 min from cervical cancer. Nearly all cervical cancers are preventable by early detection and treatment through screening or HPV vaccination. In 2018, World Health Organization (WHO) made a global call for action toward the elimination of cervical cancer. Cervical cancer screening involves a complex organized program, which begins with a call/recall system based on personal invitation of eligible women, followed by participation in screening, and leading to diagnosis, treatment, and management as appropriate. An effective cervical screening program with high coverage is dependent on each country's infrastructure and human resource capacity. Efforts to develop an effective program is particularly challenging in low and middle income countries (LMIC) where resources are limited. For an effective strategy, Turkey redesigned the country's cervical screening program. The local call/recall system and centralized monitoring system of individual women were re-vamped with an automated evaluation system. The revised screening program includes the use of primary HPV testing with a well-defined protocol outlining the algorithms of management (i.e., screening intervals and referral), a single nationwide centralized diagnostic laboratory, and a sustainable agreement with the HPV diagnostics industry. This system allows for traceable, real-time monitoring of screening visits and specimens. Turkey reports on the first four years of this re-vamped organized program and shares lessons learnt from the implementation of this new program.

Previous Papanicolaou and Hybrid Capture 2 human papillomavirus testing results of 5699 women with histologically diagnosed cervical intraepithelial neoplasia 2/3

INTRODUCTION

Cervical cancer remains an important public health problem in Chinese women owing to the lack of a national screening program. The aim of the present study was to evaluate human papillomavirus (HPV) and Papanicolaou (Pap) test results preceding the histologic diagnosis of cervical intraepithelial neoplasia 2/3 (CIN2/3) in China's largest College of American Pathologists-certified clinical laboratory.

MATERIALS AND METHODS

All cases of CIN2/3 histologically diagnosed from January 2011 to August 2016 were retrieved from the pathology department records. The Pap cytology and HPV test results from the 6 months before the CIN2/3 diagnoses were analyzed.

RESULTS

A total of 5699 patients with histologically diagnosed CIN2/3 had previous Pap and/or HPV Hybrid Capture 2 testing results within the previous 6 months. The average age was 39.5 years (range, 16-82 years). Of these patients, 4288 had Pap test findings (average, 1.5 months) available. The results were high-grade squamous intraepithelial lesion in 44.1%, low-grade squamous intraepithelial lesion in 20.0%, atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion, in 16.0%, atypical squamous cells of undetermined significance, in 12.3%, atypical glandular cells in 0.7%, and negative in 6.9%. Of the 5699 patients, 2546 had HPV Hybrid Capture 2 test results (average, 1.4 months) available. Of these, 91.7% had positive results and 8.3% had negative results. Of 1135 patients with both previous Pap and HPV results, 7.1% had negative HPV results and 8.0% had negative Pap results (P = 0.38). Only 21 patients (1.9%) had double negative results.

CONCLUSIONS

The present study has reported the previous results of HPV testing and Pap cytology for patients with high-grade cervical squamous precursor lesions in a population of women in China who had not undergone intensive previous screening. Both high-risk HPV and Pap cytology had similar negative testing rates for these women, although double negative results were less common. These results support the value of combined testing in the detection of cervical cancer precursors.

Impact of Acetic Acid on HPV Testing Using Hybrid Capture 2

As per the American Society for Colposcopy and Cervical Pathology guidelines, human papillomavirus (HPV) testing is currently used as part of cervical cancer screening and during colposcopy follow-up. The present project evaluated if the application of acetic acid (AA) impacts HPV test results.

METHODS

We conducted a prospective nonrandomized interventional study. Participants referred for colposcopy were eligible if immunocompetent, older than 18 years, and not pregnant. Women in group A (controls) received 2 consecutive HPV tests without application of AA. Women in group B had a first HPV sample collected before the application of AA and a second sample collected 3 minutes after application of AA. Samples were tested for HPV DNA with Hybrid Capture 2 (HC2) according to the manufacturer's instructions.

RESULTS

From October 17, 2012, to January 10, 2013, approximately 101 women were recruited in 2 colposcopy clinics. In each group, concordance was 98%, with only 1 participant having discordant results (testing negative on the first sample and positive on the second sample). We found no statistically significant difference in relative light units(RLUs) between groups (median of difference, - 0.02 vs -0.05 RLU; p = .93).

CONCLUSIONS

The results of this study suggest that acetic acid at concentrations of 3% to 5% and sequential cervical sampling do not modify the result of HPV testing by Hybrid Capture 2.

Initial results of population based cervical cancer screening program using HPV testing in one million Turkish women

To evaluate the Turkey's nationwide HPV DNA screening program on the basis of first 1 million screened women. Women over age 30 were invited for population based screening via HPV DNA and conventional cytology. Samples were collected by family physicians and the evaluations and reports had been performed in the National Central HPV laboratories. The acceptance rate for HPV based cervical cancer screening after first invitation was nearly 36.5%. Since HPV DNA tests have been implemented, cervical cancer screening rates have shown 4–5‐fold increase in primary level. Through the evaluation of all, HPV positivity was seen in 3.5%. The commonest HPV genotypes were 16, followed by 51, 31, 52 and 18. Among the 37.515 HPV positive cases, cytological abnormality rate was 19.1%. Among HPV positive cases, 16.962 cases had HPV 16 or 18 or other oncogenic HPV types with abnormal cytology (>ASC‐US). These patients were referred to colposcopy. The colposcopy referral rate was 1.6%. Among these, final clinico‐pathological data of 3.499 patients were normal in 1.985 patients, CIN1 in 708, CIN2 in 285, CIN3 in 436 and cancer in 85 patients and only pap‐smear program could miss 45.9% of ≥CIN3 cases. The results of 1 million women including the evaluation of 13 HPV genotypes with respect to prevalence, geographic distribution and abnormal cytology results shows that HPV DNA can be used in primary level settings to have a high coverage rated screening program and is very effective compared to conventional pap‐smear.

What's new?

In Turkey, a cervical cancer screening program using Pap smear reached only a tiny proportion of the nation's women. To sidestep the logistical challenges that hindered that approach, these authors investigated a population wide HPV testing program. HPV testing is much less expensive and easier to automate than cytological testing. The screening rates have increased 5‐fold over the cytology‐based screening program, and the HPV based program made better use of the limited personnel available to interpret cytological test results. Other developing countries looking to implement cervical cancer screening programs could look to Turkey's system as a successful model.

Comparison of Triage Strategies for HPV-Positive Women: Canadian Cervical Cancer Screening Trial Results

Background: High-risk human papillomavirus (HR-HPV) testing has become a preferred cervical cancer screening strategy in some countries due to its superior sensitivity over cytology-based methods for identifying cervical intraepithelial neoplasia of grade 2 or worse (CIN2⁺). Improved sensitivity has been accompanied by reductions in specificity and concerns regarding overscreening and overtreatment of women with transient or nonprogressing HR-HPV infections. Triage of HR-HPV⁺ women to colposcopy is, thus, warranted for appropriate management and treatment.Methods: Using data from the Canadian Cervical Cancer Screening Trial (CCCaST), we compared the performance of cytology and HR-HPV strategies to detect CIN2⁺ among HR-HPV⁺ women (age, 30-69 years). Colposcopy referral rates and performance gains from adding other HR-HPV genotypes to HPV16/18⁺ triage were also evaluated.Results: A strategy referring all women HPV16/18⁺ and HPV16/18^-, but with atypical squamous cells of undetermined significance or worse cytology (ASC-US⁺) had the highest sensitivity [82.5%; 95% confidence interval (CI), 70.9%-91.0%] but yielded the highest colposcopy referral rate. HPV16/18⁺ triage was the next most sensitive strategy (64.1%; 95% CI, 51.1%-75.7%). Low-grade squamous intraepithelial lesion or worse cytology (LSIL⁺) triage yielded a low sensitivity (32.8%; 95% CI, 21.9%-45.4%) but had the most favorable specificity (93.6%; 95% CI, 91.0%-95.6%), positive predictive value (41.5%; 95% CI, 28.1%-55.9%), and colposcopy referral rate of strategies examined. HPV viral load triage strategies did not perform optimally overall. Inclusion of HR-HPV genotypes 31 and 52 to HPV16/18⁺ triage provided the highest sensitivities.Conclusion: Concerns surrounding HPV-based screening can be effectively mitigated via triage.Impact: Balancing the benefits of HPV-based primary cervical screening with informed management recommendations for HR-HPV⁺ women may decide the success of its widening utilization. Cancer Epidemiol Biomarkers Prev; 26(6); 923-9. ©2017 AACR.

Epidemiologic Evaluation of Human Papillomavirus Type Competition and the Potential for Type Replacement Post-Vaccination

Background

Millions of women have been vaccinated with one of two first-generation human papillomavirus (HPV) vaccines. Both vaccines remain in use and target two oncogenic types (HPVs 16 and 18); however, if these types naturally compete with others that are not targeted, type replacement may occur following reductions in the circulating prevalence of targeted types. To explore the potential for type replacement, we evaluated natural HPV type competition in unvaccinated females.

Methods

Valid HPV DNA typing information was available from five epidemiological studies conducted in Canada and Brazil (n = 14,685; enrollment across studies took place between1993 and 2010), which used similar consensus-primer PCR assays, capable of detecting up to 40 HPV types. A total of 38,088 cervicovaginal specimens were available for inclusion in our analyses evaluating HPV type-type interactions involving vaccine-targeted types (6, 11, 16, and 18), and infection with each of the other HPV types.

Results

Across the studies, the average age of participants ranged from 21.0 to 43.7 years. HPV16 was the most common type (prevalence range: 1.0% to 13.8%), and in general HPV types were more likely to be detected as part of a multiple infection than as single infections. In our analyses focusing on each of the vaccine-targeted HPV types separately, many significant positive associations were observed (particularly involving HPV16); however, we did not observe any statistically significant negative associations.

Conclusions

Our findings suggest that natural HPV type competition does not exist, and that type replacement is unlikely to occur in vaccinated populations.

Cost-Effectiveness of Primary HPV Testing, Cytology and Co-testing as Cervical Cancer Screening for Women Above Age 30 Years

BACKGROUND

Cervical cancer screening guidelines for women aged ≥30 years allow for co-testing or primary cytology testing. Our objective was to determine the test characteristics and costs associated with Cytology, HPV and Co-testing screening strategies.

MAIN METHODS

Retrospective cohort study of women undergoing cervical cancer screening with both cytology and HPV (Hybrid Capture 2) testing from 2004 to 2010 in an integrated health system. The electronic health record was used to identify women aged ≥30 years who had co-testing. Unsatisfactory or unavailable test results and incorrectly ordered tests were excluded. The main outcome was biopsy-proven cervical intraepithelial neoplasia grade 3 or higher (CIN3+).

KEY RESULTS

The final cohort consisted of 99,549 women. Subjects were mostly white (78.4 %), married (70.7 %), never smokers (61.3 %) and with private insurance (86.1 %). Overall, 5121 (5.1 %) tested positive for HPV and 6115 (6.1 %) had cytology ≥ ASCUS; 1681 had both and underwent colposcopy and 310 (0.3 %) had CIN3+. Sensitivity for CIN3+ was 91.9 % for Primary Cytology, 99.4 % for Co-testing, and 94.8 % for Primary HPV; specificity was 97.3 % for Co-testing and Primary Cytology and 97.9 % for Primary HPV. Over a 3-year screening interval, Primary HPV detected more cases of CIN3+ and was less expensive than Primary Cytology. Co-testing detected 14 more cases of CIN3+ than Primary HPV, but required an additional 100,277 cytology tests and 566 colposcopies at an added cost of $2.38 million, or $170,096 per additional case detected.

CONCLUSIONS

Primary HPV was more effective and less expensive than Primary Cytology. Primary HPV screening appears to represent a cost-effective alternative to Co-testing.

Human papillomavirus testing versus cytology in primary cervical cancer screening: End-of-study and extended follow-up results from the Canadian cervical cancer screening trial

The Canadian Cervical Cancer Screening Trial was a randomized controlled trial comparing the performance of human papillomavirus (HPV) testing and Papanicolaou cytology to detect cervical intraepithelial neoplasia of grades 2 or worse (CIN2+) among women aged 30-69 years attending routine cervical cancer screening in Montreal and St. John's, Canada (n = 10,154). We examined screening and prognostic values of enrollment cytologic and HPV testing results. Extended follow-up data were available for St. John's participants (n = 5,754; 501,682.6 person-months). HPV testing detected more CIN2+ than cytology during protocol-defined (82.9 vs. 44.4%) and extended (54.2 vs. 19.3%) follow-up periods, respectively. Three-year risks ranged from 0.87% (95% CI: 0.37-2.05) for HPV-/Pap- women to 35.77% (95% CI: 25.88-48.04) for HPV+/Pap+ women. Genotype-specific risks ranged from 0.90% (95% CI: 0.40-2.01) to 43.84% (95% CI: 32.42-57.24) among HPV- and HPV16+ women, respectively, exceeding those associated with Pap+ or HPV+ results taken individually or jointly. Ten-year risks ranged from 1.15% (95% CI: 0.60-2.19) for HPV-/Pap- women to 26.05% (95% CI: 15.34-42.13) for HPV+/Pap+ women and genotype-specific risks ranged from 1.13% (95% CI: 0.59-2.14) to 32.78% (95% CI: 21.15-48.51) among women testing HPV- and HPV16+, respectively. Abnormal cytology stratified risks most meaningfully for HPV+ women. Primary HPV testing every 3 years provided a similar or greater level of reassurance against disease risks as currently recommended screening strategies. HPV-based cervical screening may allow for greater disease detection than cytology-based screening and permit safe extensions of screening intervals; genotype-specific testing could provide further improvement in the positive predictive value of such screening.

HPV DNA testing with cytology triage in cervical cancer screening: Influence of revealing HPV infection status

BACKGROUND

Knowledge of cervical human papillomavirus (HPV) status might influence a cytotechnician's assessment of cellular abnormalities. The authors compared original cytotechnicians' Papanicolaou (Pap) readings for which HPV status was concealed with Pap rereads for which HPV status was revealed separately for 3 screening populations.

METHODS

Previously collected cervical Pap smears and clinical data were obtained from the Canadian Cervical Cancer Screening Trial (study A), the Democratic Republic of Congo Community-Based Screening Study (study B), and the Brazilian Investigation into Nutrition and Cervical Cancer Prevention (study C). Smears were reread with knowledge of HPV status for all HPV-positive women as well as a sample of HPV-negative women. Diagnostic performance of Pap cytology was compared between original readings and rereads.

RESULTS

A total of 1767 Pap tests were reread. Among 915 rereads for HPV-positive women, the contrast between "revealed" and "concealed" Pap readings demonstrated revisions from negative to positive results for 109 women (cutoff was atypical squamous cells of undetermined significance or worse) and 124 women (cutoff was low-grade squamous intraepithelial lesions [LSIL] or worse). For a disease threshold of cervical intraepithelial neoplasia of grade 2 or worse, specificity significantly declined at the atypical squamous cells of undetermined significance cutoff for studies A (86.6% to 75.3%) and C (42.5% to 15.5%), and at the LSIL cutoff for study C (61.9% to 37.6%). Sensitivity remained nearly unchanged between readings, except in study C, in which reread performance was superior (91.3% vs 71.9% for the LSIL cutoff).

CONCLUSIONS

A reduction in the diagnostic accuracy of Pap cytology was observed when revealing patients' cervical HPV status, possibly due to a heightened awareness of potential abnormalities, which led to more false-positive results.

CCNA1 promoter methylation: a potential marker for grading Papanicolaou smear cervical squamous intraepithelial lesions

BACKGROUND

From our previous study, we established that cyclin A1 (CCNA1) promoter methylation is strongly correlated with multistep progression of HPV-associated cervical cancer, suggesting potential use as a diagnostic maker of disease.

OBJECTIVES

The purpose of the present study was to assess the prevalence of CCNA1 promoter methylation in residual cervical cells isolated from liquid-based cytology that underwent hrHPV DNA screening for cervical cancer, and then to evaluate this marker for diagnostic accuracy using parameters like sensitivity, specificity, predictive values and likelihood ratio.

METHODS

In this retrospective study, histopathology was used as the gold standard method with specimens separated into the following groups: negative (n=31), low- grade squamous intraepithelial lesions (LSIL, n=34) and high-grade squamous intraepithelial lesions or worse (HSIL+, n=32). The hrHPV was detected by Hybrid Capture 2 (HC2) and CCNA1 promoter methylation was examined by CCNA1 duplex methylation specific PCR.

RESULTS

The results showed the frequencies of CCNA1 promoter methylation were 0%, 5.88% and 83.33%, while the percentages of hrHPV were 66.67%, 82.35% and 100% in the negative, LSIL and HSIL+ groups, respectively. Although hrHPV infection showed high frequency in all three groups, it could not differentiate between the different groups and grades of precancerous lesions. In contrast, CCNA1 promoter methylation clearly distinguished between negative/LSIL and HSIL+, with high levels of all statistic parameters.

CONCLUSION

CCNA1 promoter methylation is a potential marker for distinguishing between histologic negative/LSIL and HSIL+using cervical cytology samples.

Effect of vaginal self-sampling on cervical cancer screening rates: a community-based study in Newfoundland

Background

Cervical cancer is highly preventable and treatable if detected early through regular screening. Women in the Canadian province of Newfoundland & Labrador have relatively low rates of cervical cancer screening, with rates of around 40 % between 2007 and 2009. Persistent infection with oncogenic human papillomavirus (HPV) is a necessary cause for the development of cervical cancer, and HPV testing, including self-sampling, has been suggested as an alternative method of cervical cancer screening that may alleviate some barriers to screening. Our objective was to determine whether offering self-collected HPV testing screening increased cervical cancer screening rates in rural communities.

Methods

During the 2-year study, three community-based cohorts were assigned to receive either i) a cervical cancer education campaign with the option of HPV testing; ii) an educational campaign alone; iii) or no intervention. Self-collection kits were offered to eligible women at family medicine clinics and community centres, and participants were surveyed to determine their acceptance of the HPV self-collection kit. Paired proportions testing for before-after studies was used to determine differences in screening rates from baseline, and Chi Square analysis of three dimensional 2 × 2 × 2 tables compared the change between communities.

Results

Cervical cancer screening increased by 15.2 % (p < 0.001) to 67.4 % in the community where self-collection was available, versus a 2.9 % increase (p = 0.07) in the community that received educational campaigns and 8.5 % in the community with no intervention (p = 0.193). The difference in change in rates was statistically significant between communities A and B (p < 0.001) but not between communities A and C (p = 0.193). The response rate was low, with only 9.5 % (168/1760) of eligible women opting to self-collect for HPV testing. Of the women who completed self-collection, 15.5 % (26) had not had a Pap smear in the last 3 years, and 88.7 % reported that they were somewhat or very satisfied with self-collection.

Conclusions

Offering self-collected HPV testing increased the cervical cancer screening rate in a rural NL community. Women who completed self-collection had generally positive feelings about the experience. Offering HPV self-collection may increase screening compliance, particularly among women who do not present for routine Pap smears.

Methylation of viral and host genes and severity of cervical lesions associated with human papillomavirus type 16

Methylation of human papillomavirus (HPV) and host genes may predict cervical cancer risk. We examined the methylation status of selected sites in HPV16 and human genes in DNA extracted from exfoliated cervical cell samples of 244 women harboring HPV16-positive cancer or cervical intraepithelial neoplasia (CIN) or negative for intraepithelial lesions or malignancy (NILM). We quantified the methylation of CpG sites in the HPV16 L1 gene (CpG 6367 and 6389) and in the human genes EPB41L3 (CpG 438, 427, 425) and LMX1 (CpG 260, 262, 266, 274) following bisulfite treatment and pyrosequencing. Receiver operating characteristic (ROC) curves were used to analyze the diagnostic utility of methylation level for the different sites and for a joint predictor score. Methylation in all sites significantly increased with lesion severity (p < 0.0001). Area under the curve (AUC) was highest among the CIN2/3 vs. cancer ranging from 0.786 to 0.853 among the different sites. Site-specific methylation levels strongly discriminated CIN2/3 from NILM/CIN1 and cancer from CIN2/3 (range of odds ratios [OR]: 3.69-12.76, range of lower 95% confidence bounds: 1.03-4.01). When methylation levels were mutually adjusted for each other EPB41L3 was the only independent predictor of CIN2/3 vs. NILM/CIN1 contrasts (OR = 9.94, 95%CI: 2.46-40.27). High methylation levels of viral and host genes are common among precancerous and cancer lesions and can serve as independent risk biomarkers. Methylation of host genes LMX1 and EPB41L3 and of the viral HPV16 L1 sites has the potential to distinguish among precancerous lesions and to distinguish the latter from invasive disease.

A survey of population-based utility scores for cervical cancer prevention

Background

With human papillomavirus (HPV) vaccination introduced in a number of countries, there is considerable interest in evaluating the cost-effectiveness of HPV testing as the primary cervical screening test in these settings. However, the availability of utility scores for these newer interventions is limited. Our aim in this paper is to present utility scores for HPV vaccination, HPV testing and cytology based screening states among women targeted for cervical screening.

Methods

We invited a random sample of women targeted for cervical screening (aged 20-69 years) living in Sydney, Australia, to participate in a face-to-face interview. Participants were asked to indicate preferences (rank and utility scores) for 10 hypothetical health states relating to HPV vaccination, cytology and primary HPV screening, cervical precursor disease and early stage cervical cancer. Preferences for hypothetical health states were measured through ranking then a two-stage standard gamble. Each participant’s own health state was measured as a utility score using the EQ5D. Potential differences by age were assessed using the Wilcox Rank Sum test.

Results

A maximum of 276 women were contacted, of which 43 (mean age 49 years) agreed to be interviewed (15.6%). The overall health state of women as measured by the EQ5D was 0.86 (95% CI: 0.83-0.89). Of the 10 health states, the highest ranked were ‘normal cytology’ and ‘HPV vaccination’ (equal 1^st). States involving an HPV positive result with a subsequent normal cytology or colposcopy were ranked below those for low grade cytological abnormalities with or without a subsequent colposcopic normal result (ranks 3-4 vs. 4-5). However, mean utility scores were broadly similar for all health states, except cervical cancer. No significant differences in scores were identified between age groups.

Conclusion

Our survey suggests health states relating to HPV testing are ranked below ‘low grade cytology’ disease abnormalities. However, this difference was minimal on the utility scale, as most values for health states were largely clustered. These results provide a preliminary set of non-clinic population-based utilities that may be used with other values to explore the economic implications of introducing HPV testing as a primary screening tool in the context of HPV vaccination.

Electronic supplementary material

The online version of this article (doi:10.1186/1756-0500-7-899) contains supplementary material, which is available to authorized users.

Evaluation of human papillomavirus type replacement postvaccination must account for diagnostic artifacts: masking of HPV52 by HPV16 in anogenital specimens

It has been hypothesized that, following a reduction in human papillomavirus (HPV) vaccine-targeted genotypes, an increase in prevalence of other HPV types may occur due to reduced competition during natural infection. Any apparent postvaccination increase must be distinguished from diagnostic artifacts consequent to consensus PCR assays failing to detect HPV types present in low copy numbers in coinfected specimens (under the assumption that with a drop in vaccine-preventable types there may be increased detection of previously "masked" types). We reanalyzed anogenital specimens to evaluate unmasking of HPV52 that may be caused by elimination of HPV16. Using highly sensitive type-specific real-time HPV52 PCR, we retested 1,200 anogenital specimens (all HPV52 negative according to consensus PCR assays) from six epidemiologic studies (200 specimens/study; 100 HPV16(+)/study). Multivariate logistic regression, with adjustment for age and number of sexual partners, was used to evaluate the association between HPV16 positivity and detection of HPV52. In our pooled analysis (n = 1,196), the presence of HPV16 was positively associated with HPV52 detection [adjusted OR, 1.47; 95% confidence interval (CI), 0.76-2.82]. In our separate (study specific) analyses, a statistically significant association was observed in one study that included HIV-infected males (HIPVIRG study; adjusted OR, 3.82; 95% CI, 1.19-12.26). We observed a positive association between HPV16 viral load (tertiles) and detection of HPV52 (P for trend = 0.003). These results indicate that diagnostic artifacts, resulting from unmasking of HPV52, may occur in some settings in the evaluation of HPV type replacement. Additional studies exploring the extent and severity of unmasking are needed.

Comparing the cost-effectiveness of two- and three-dose schedules of human papillomavirus vaccination: a transmission-dynamic modelling study

BACKGROUND

Recent evidence suggests that two doses of HPV vaccines may be as protective as three doses in the short-term. We estimated the incremental cost-effectiveness of two- and three-dose schedules of girls-only and girls & boys HPV vaccination programmes in Canada.

METHODS

We used HPV-ADVISE, an individual-based transmission-dynamic model of multi-type HPV infection and diseases (anogenital warts, and cancers of the cervix, vulva, vagina, anus, penis and oropharynx). We conducted the analysis from the health payer perspective, with a 70-year time horizon and 3% discount rate, and performed extensive sensitivity analyses, including duration of vaccine protection and vaccine cost.

FINDINGS

Assuming 80% coverage and a vaccine cost per dose of $85, two-dose girls-only vaccination (vs. no vaccination) produced cost/quality-adjusted life-year (QALY)-gained varying between $7900-24,300. The incremental cost-effectiveness ratio of giving the third dose to girls (vs. two doses) was below $40,000/QALY-gained when: (i) three doses provide longer protection than two doses and (ii) two-dose protection was shorter than 30 years. Vaccinating boys (with two or three doses) was not cost-effective (vs. girls-only vaccination) under most scenarios investigated.

INTERPRETATION

Two-dose HPV vaccination is likely to be cost-effective if its duration of protection is at least 10 years. A third dose of HPV vaccine is unlikely to be cost-effective if two-dose duration of protection is longer than 30 years. Finally, two-dose girls & boys HPV vaccination is unlikely to be cost-effective unless the cost per dose for boys is substantially lower than the cost for girls.

The road ahead for cervical cancer prevention and control

Since the early 1950s, Papanicolaou ("Pap") cytology screening has dramatically reduced cervical cancer mortality in most high-income settings. Currently, human papillomavirus (hpv) vaccination has the greatest potential to reduce the global burden of cervical cancer and precancerous lesions. However, as the prevalence of precancerous lesions declines, maintaining cytology as the primary screening test in settings with established programs might become less efficient. A reduction in test performance (sensitivity, specificity, and positive predictive value) would lead to an increase in unnecessary colposcopy referrals. Fortunately, hpv dna testing has emerged as a suitable candidate to replace cytology. Compared with the Pap test, hpv testing is less specific but much more sensitive in detecting high-grade precancerous lesions, less prone to human error, and more reproducible across settings. Linkage of hpv vaccination and screening registries could serve the added role of monitoring vaccine efficacy. As a triage test, cytology is expected to perform with sufficient accuracy because most hpv-positive smears would contain relevant abnormalities. This approach and others-for example, hpv testing followed by genotyping-are being evaluated in large population studies and have already been recommended in some settings. Other specific biomarkers that might perform well for screening and triage include hpv E6/E7 messenger rna testing, methylation of host or viral genes, and p16(INK4a) staining. Considering the rapid pace of major discoveries and the anticipated arrival of a nonavalent hpv vaccine (currently in phase iii trials), the evidence base in this field has become an elusive target and will continue to be an obstacle for policymakers.

A new method to address verification bias in studies of clinical screening tests: cervical cancer screening assays as an example

OBJECTIVES

Studies to evaluate clinical screening tests often face the problem that the "gold standard" diagnostic approach is costly and/or invasive. It is therefore common to verify only a subset of negative screening tests using the gold standard method. However, undersampling the screen negatives can lead to substantial overestimation of the sensitivity and underestimation of the specificity of the diagnostic test. Our objective was to develop a simple and accurate statistical method to address this "verification bias."

STUDY DESIGN AND SETTING

We developed a weighted generalized estimating equation approach to estimate, in a single model, the accuracy (eg, sensitivity/specificity) of multiple assays and simultaneously compare results between assays while addressing verification bias. This approach can be implemented using standard statistical software. Simulations were conducted to assess the proposed method. An example is provided using a cervical cancer screening trial that compared the accuracy of human papillomavirus and Pap tests, with histologic data as the gold standard.

RESULTS

The proposed approach performed well in estimating and comparing the accuracy of multiple assays in the presence of verification bias.

CONCLUSION

The proposed approach is an easy to apply and accurate method for addressing verification bias in studies of multiple screening methods.

Comparative study of the cervista and hybrid capture 2 methods in detecting high-risk human papillomavirus in cervical lesions

High-risk human papillomavirus (HR HPV) testing is important for the follow-up of patients with cytological abnormalities. This study was undertaken to compare the clinical value of the Cervista and hybrid capture 2 (HC2) tests for detection of HR HPV in cervical lesions. Overall 439 cervical specimens with abnormal cytology and 22 normal cervical specimens were subjected to the Cervista and HC2 tests. HPV positivity and its predictive value for high-grade cervical lesions were assessed. The Cervista and HC2 tests showed comparable HR HPV detection rates in women with all cytological and histological diagnoses, with a positive and negative percent agreement of 90.8% and 64.5%, respectively. The two methods had a same sensitivity of 90% in detecting CIN II or greater cervical lesions, while the specificity for the Cervista test and HC2 assay was 47% and 43%, respectively. The positive rate for the Cervista assay probe set A9 increased with the histological severity, ranging from 25.0% in normal specimens to 69.5% in high-grade lesions. In conclusion, the clinical performance for the Cervista test is as excellent as the HC2 test in detecting HR HPV and predicting high-grade cervical lesions.

Comparative cost-effectiveness of the quadrivalent and bivalent human papillomavirus vaccines: a transmission-dynamic modeling study

BACKGROUND

The quadrivalent and bivalent human papillomavirus (HPV) vaccines are now licensed in several countries. We compared the cost-effectiveness of the HPV vaccines to provide evidence for policy decisions.

METHODS

We developed HPV-ADVISE, a multi-type individual-based transmission-dynamic model of HPV infection and disease (anogenital warts, and cervical, anogenital and oropharyngeal cancers). We calibrated the model to sexual behavior and epidemiologic data from Canada, and estimated quality-adjusted life-years (QALYs) lost and costs ($CAN 2010) from the literature. Vaccine-type efficacy was based on a systematic literature review. The analysis was performed from the healthcare provider perspective, and costs and benefits were discounted at 3%. Predictions are presented using the median [10th;90th percentiles] of simulations.

RESULTS

Under base-case assumptions (vaccinating 10-year-old girls, 80% coverage, $95/dose), using the quadrivalent and bivalent vaccines is estimated to cost $15,528 [12,056;19,140] and $20,182 [15,531;25,240] per QALY-gained, respectively. At equal price, the quadrivalent vaccine is more cost-effective than bivalent under all scenarios investigated, except when assuming longer duration of protection for the bivalent and minimal anogenital warts burden. Under base-case assumptions, the maximum additional cost per dose for the quadrivalent vaccine to remain more cost-effective than the bivalent is $32 [17;46] (using a $40,000/QALY-gained threshold). Results were most sensitive to discounting, time-horizon, differences in durations of protection and anogenital warts burden.

CONCLUSIONS

Vaccinating pre-adolescent girls against HPV is predicted to be highly cost-effective. If equally priced, the quadrivalent is the most economically desirable vaccine. However, ultimately, the most cost-effective HPV vaccine will be determined by their relative price.

Vaccinating Girls and Boys with Different Human Papillomavirus Vaccines: Can It Optimise Population-Level Effectiveness?

BACKGROUND

Decision-makers may consider vaccinating girls and boys with different HPV vaccines to benefit from their respective strengths; the quadrivalent (HPV4) prevents anogenital warts (AGW) whilst the bivalent (HPV2) may confer greater cross-protection. We compared, to a girls-only vaccination program with HPV4, the impact of vaccinating: 1) both genders with HPV4, and 2) boys with HPV4 and girls with HPV2.

METHODS

We used an individual-based transmission-dynamic model of heterosexual HPV infection and diseases. Our base-case scenario assumed lifelong efficacy of 100% against vaccine types, and 46,29,8,18,6% and 77,43,79,8,0% efficacy against HPV-31,-33,-45,-52,-58 for HPV4 and HPV2, respectively.

RESULTS

Assuming 70% vaccination coverage and lifelong cross-protection, vaccinating boys has little additional benefit on AGW prevention, irrespective of the vaccine used for girls. Furthermore, using HPV4 for boys and HPV2 for girls produces greater incremental reductions in SCC incidence than using HPV4 for both genders (12 vs 7 percentage points). At 50% vaccination coverage, vaccinating boys produces incremental reductions in AGW of 17 percentage points if both genders are vaccinated with HPV4, but increases female incidence by 16 percentage points if girls are switched to HPV2 (heterosexual male incidence is incrementally reduced by 24 percentage points in both scenarios). Higher incremental reductions in SCC incidence are predicted when vaccinating boys with HPV4 and girls with HPV2 versus vaccinating both genders with HPV4 (16 vs 12 percentage points). Results are sensitive to vaccination coverage and the relative duration of protection of the vaccines.

CONCLUSION

Vaccinating girls with HPV2 and boys with HPV4 can optimize SCC prevention if HPV2 has higher/longer cross-protection, but can increase AGW incidence if vaccination coverage is low among boys.

Prevalence and determinants of high-risk human papillomavirus infection in women from a sub-Saharan African community

BACKGROUND

Human papillomavirus infection with high-risk types (HR-HPV) is a necessary cause of cervical cancer, the most common malignancy among sub-Saharan African women. Little is known about prevalence of cervical HR-HPV infection in this region.

METHODS

A cross-sectional study of 1528 women examined the determinants of HR-HPV infection among women in Kinshasa, Democratic Republic of Congo. Information was collected on sociodemographic, reproductive, lifestyle characteristics, and health-seeking behaviors. Cervical samples were tested for HPV-DNA by Hybrid Capture 2. Unconditional logistic regression identified predictors of HPV positivity.

RESULTS

HR-HPV prevalence was 12.5% in all women and 8.7% in women with normal cytology. Prevalence was highest (18.3%) in individuals <35 years of age and gradually decreased with age. Excess HR-HPV infection risk was observed in women who were smokers (odds ratio [OR] = 1.60; 95% confidence interval [CI]: 1.11-2.31), divorced/separated (OR = 1.60; 95% CI: 1.11-2.32), in polygamous marriages (OR = 1.28; 95% CI: 0.90-1.82), using medical contraceptives (OR = 2.40; 95% CI: 1.20-4.80), and who preferred male physicians (OR = 1.90; 95% CI: 1.20-3.05). A statistically marginal increase was found in women whose partners had sex with prostitutes (OR = 2.40; 95% CI: 0.72-8.01). A higher standard of living was associated with reduced risk.

CONCLUSION

HR-HPV positivity was associated with behavioral and sexual characteristics thought to affect risk of new infections and immune function. However, HPV prevalence did not correlate with numbers of sex partners, possibly because of a high HPV infection rate per sexual contact or because subjects were older than 30 years. Our study should assist in designing strategies for control of cervical cancer in this low-resource, high cervical cancer risk setting in sub-Saharan Africa.

Practice guidelines for the early detection of cervical cancer in Korea: Korean Society of Gynecologic Oncology and the Korean Society for Cytopathology 2012 edition

The consensus guideline development committee of Korean Society of Gynecologic Oncology was reconvened in March 2012. The committee consisted of 36 experts representing 12 university hospitals and professional organizations. The objective of this committee was to develop standardized guidelines for cervical cancer screening tests for Korean women and to distribute these guidelines to every clinician, eventually improving the quality of medical care. Since the establishment of the consensus guideline development committee, evidence-based guidelines have either been developed de novo considering specific Korean situations or by adaptation of preexisting consensus guidelines from other countries. Recommendations for cervical cancer screening tests, management of atypical squamous and glandular cells, and management of low-grade and high-grade squamous intraepithelial lesions were developed. Additionally, recommendations for human papillomavirus DNA testing and recommendations for adolescent and pregnant women with abnormal cervical screening test results were also included.

Population-level impact of the bivalent, quadrivalent, and nonavalent human papillomavirus vaccines: a model-based analysis

BACKGROUND

Bivalent and quadrivalent human papillomavirus (HPV) vaccines are now licensed in several countries. Furthermore, clinical trials examining the efficacy of a nonavalent vaccine are underway. We aimed to compare the potential population-level effectiveness of the bivalent, quadrivalent, and candidate nonavalent HPV vaccines.

METHODS

We developed an individual-based, transmission-dynamic model of HPV infection and disease in a population stratified by age, gender, sexual activity, and screening behavior. The model was calibrated to highly stratified sexual behavior, HPV epidemiology, and cervical screening data from Canada.

RESULTS

Under base case assumptions, vaccinating 12-year-old girls (70% coverage) with the bivalent (quadrivalent) vaccine is predicted to reduce the cumulative incidence of anogenital warts (AGWs) by 0.0% (72.1%), diagnosed cervical intraepithelial neoplasia lesions 2 and 3 (CIN2 and -3) by 51.0% (46.1%), and cervical squamous cell carcinoma (SCC) by 31.9% (30.5%), over 70 years. Changing from a bivalent (quadrivalent) to a nonavalent vaccine is predicted to reduce the cumulative number of AGW episodes by an additional 66.7% (0.0%), CIN2 and -3 episodes by an additional 9.3% (12.5%), and SCC cases by an additional 4.8% (6.6%) over 70 years. Differences in predicted population-level effectiveness between the vaccines were most sensitive to duration of protection and the time horizon of analysis. The vaccines produced similar effectiveness at preventing noncervical HPV-related cancers.

CONCLUSIONS

The bivalent vaccine is expected to be slightly more effective at preventing CIN2 and -3 and SCC in the longer term, whereas the quadrivalent vaccine is expected to substantially reduce AGW cases shortly after the start of vaccination programs. Switching to a nonavalent vaccine has the potential to further reduce precancerous lesions and cervical cancer.

New insights into cervical cancer screening

Worldwide, cervical cancer is a leading cause of cancer related morbidity and mortality. For over 50 years, cervical cytology has been the gold standard for cervical cancer screening. Because of its profound effect on cervical cancer mortality in nations that have adopted screening programs, the Pap smear is widely accepted as the model screening test. Since its introduction, many studies have analyzed the Pap smear and found that it is not without its shortcomings including low sensitivity for detection of cervical intraepithelial neoplasia 2/3. Additionally, the discovery of infection with the human papillomavirus (HPV) as a necessary step in the development of cervical cancer has led to the development of HPV testing as an adjunct to cytology screening. More recently, researchers have compared HPV testing and cytology in the primary screening of cervical cancer. In this review, we will discuss cytologic testing limitations, the role of HPV DNA testing as an alternative screening tool, the impact of the HPV vaccine on screening, and future directions in cervical cancer screening.

Recommendations of the IOM clinical preventive services for women committee: implications for obstetricians and gynecologists

PURPOSE OF REVIEW

In July 2011, in response to language in the Affordable Care Act (ACA) the Office of the Assistant Secretary for Planning and Evaluation of the US Department of Health and Human Services (HHS) tasked the Institute of Medicine (IOM) to develop a report on the clinical preventive services necessary for women. The committee proposed eight new clinical preventive service recommendations aimed at closing significant gaps in preventive healthcare. This article reviews the process, findings, and the implications for obstetrician gynecologists and other primary care clinicians. Obstetricians and gynecologists play a major role in delivering primary care to women and many of the services recommended by the Committee are part of the core set of obstetrics and gynecology services.

RECENT FINDINGS

The women's health amendment to the ACA (Federal Register, 2010) requires that new private health plans cover - with no cost-sharing requirements - preventive healthcare services for women. Congress requested that a review be conducted to ascertain whether there were any additional needed preventive services specific to women's health that should be included.

SUMMARY

The IOM Committee on Preventive Services for Women recommended eight clinical measures specific to women's health that should be considered for coverage without co-payment. The US Department of HHS reviewed and adopted these recommendations, and, as a result, new health plans will need to include these services as part of insurance policies with plan years beginning on or after 1 August 2012. The authors discuss the implications of the IOM recommendations on practicing clinicians and on their potential impact on women's health and well being.

Canadian oncogenic human papillomavirus cervical infection prevalence: systematic review and meta-analysis

BACKGROUND

Oncogenic human papillomavirus (HPV) infection prevalence is required to determine optimal vaccination strategies. We systematically reviewed the prevalence of oncogenic cervical HPV infection among Canadian females prior to immunization.

METHODS

We included studies reporting DNA-confirmed oncogenic HPV prevalence estimates among Canadian females identified through searching electronic databases (e.g., MEDLINE) and public health websites. Two independent reviewers screened literature results, abstracted data and appraised study quality. Prevalence estimates were meta-analyzed among routine screening populations, HPV-positive, and by cytology/histology results.

RESULTS

Thirty studies plus 21 companion reports were included after screening 837 citations and 120 full-text articles. Many of the studies did not address non-response bias (74%) or use a representative sampling strategy (53%). Age-specific prevalence was highest among females aged < 20 years and slowly declined with increasing age. Across all populations, the highest prevalence estimates from the meta-analyses were observed for HPV types 16 (routine screening populations, 8 studies: 8.6% [95% confidence interval 6.5-10.7%]; HPV-infected, 9 studies: 43.5% [28.7-58.2%]; confirmed cervical cancer, 3 studies: 48.8% [34.0-63.6%]) and 18 (routine screening populations, 8 studies: 3.3% [1.5-5.1%]; HPV-infected, 9 studies: 13.6% [6.1-21.1%], confirmed cervical cancer, 4 studies: 17.1% [6.4-27.9%].

CONCLUSION

Our results support vaccinating females < 20 years of age, along with targeted vaccination of some groups (e.g., under-screened populations). The highest prevalence occurred among HPV types 16 and 18, contributing a combined cervical cancer prevalence of 65.9%. Further cancer protection is expected from cross-protection of non-vaccine HPV types. Poor study quality and heterogeneity suggests that high-quality studies are needed.

Human papillomavirus testing in primary cervical screening and the cut-off level for hybrid capture 2 tests: systematic review

OBJECTIVE

To determine the trade-off between the sensitivity and the specificity for high grade cervical intraepithelial neoplasia at hybrid capture 2 cut-off values above the standard ≥ 1 relative light units/cut-off level (rlu/co).

DESIGN

Systematic review.

DATA SOURCES

PubMed.

STUDY SELECTION

Randomised controlled trials in primary cervical screening using hybrid capture 2 testing in the intervention arms. Articles published until August 2010 were included if the numbers of women with positive test results and with cervical intraepithelial neoplasia were stratified by hybrid capture 2 cut-off levels.

PARTICIPANTS

Women in the baseline screening rounds of the trials.

INTERVENTIONS

Hybrid capture 2 screening in the baseline round including the diagnostic follow-up as practised in the randomised controlled trials and as reported by hybrid capture 2 cut-off values.

RESULTS

Owing to heterogeneity in the trials, meta-analysis was not possible. Including cut-off values up to ≥ 10 rlu/co, 25 observation points were available for analysis. The relative sensitivity for cervical intraepithelial neoplasia grade III or higher at cut-off levels of ≥ 2, ≥ 4 or ≥ 5, and ≥ 10 rlu/co compared with a cut-off level of ≥ 1 rlu/co varied by trial, but at their lowest they were 0.97, 0.92, and 0.91, respectively. A similar pattern was observed for cervical intraepithelial neoplasia grade II or higher. The specificity would increase by at least 1%, 2%, and 3%, respectively, so that up to 24%, 39%, and 53%, of positive hybrid capture 2 test results not associated with high grade neoplasia could be avoided. Only two outliers existed to this general pattern.

CONCLUSIONS

Although the data were derived from the baseline screening rounds only, the decrease in the sensitivity for high grade cervical intraepithelial neoplasia using a hybrid capture 2 cut-off level between ≥ 2 rlu/co and ≥ 10 rlu/co seemed acceptable given the international recommendations for testing for human papillomavirus DNA in cervical screening, which require 90% or more sensitivity for cervical intraepithelial neoplasia grade II or higher compared with hybrid capture 2 at ≥ 1 rlu/co. The data suggest that the hybrid capture 2 cut-off level could be increased in primary screening; this seems reasonably safe and is significantly less burdensome for women.

Promising strategies for cervical cancer screening in the post-human papillomavirus vaccination era

Human papillomavirus (HPV) vaccination is expected to reduce the burden of cervical cancer in most settings; however, it is also expected to interfere with the effectiveness of screening. In the future, maintaining Pap cytology as the primary cervical screening test may become too costly. As the prevalence of cervical dysplasias decreases, the positive predictive value of the Pap test will also decrease, and, as a result, more women will be referred for unnecessary diagnostic procedures and follow-up. HPV DNA testing has recently emerged as the most likely candidate to replace cytology for primary screening. It is less prone to human error and much more sensitive than the Pap smear in detecting high-grade cervical lesions. Incorporating this test would improve the overall quality of screening programs and allow spacing out screening tests, while maintaining safety and lowering costs. Although HPV testing is less specific than Pap cytology, this issue could be resolved by reserving the latter for the more labour-efficient task of triaging HPV-positive cases. Because most HPV-positive smears would contain relevant abnormalities, Pap cytology would be expected to perform with sufficient accuracy under these circumstances. HPV Pap triage would also provide a low-cost strategy to monitor long-term vaccine efficacy. Although demonstration projects could start implementing HPV testing as a population screening tool, more research is needed to determine the optimal age to initiate screening, the role of HPV typing and other markers of disease progression, and appropriate follow-up algorithms for HPV-positive and Pap-negative women.

Understanding differences in predictions of HPV vaccine effectiveness: A comparative model-based analysis

Mathematical models of HPV vaccine effectiveness and cost-effectiveness have produced conflicting results. The aim of this study was to use mathematical models to compare and isolate the impact of the assumptions most commonly made when modeling the effectiveness of HPV vaccines. Our results clearly show that differences in how we model natural immunity, herd immunity, partnership duration, HPV types, and waning of vaccine protection lead to important differences in the predicted effectiveness of HPV vaccines. These results are important and useful to assist modelers/health economists in choosing the appropriate level of complexity to include in their models, provide epidemiologists with insight on key data necessary to increase the robustness of model predictions, and help decision makers better understand the reasons underlying conflicting results from HPV models.

A randomized controlled trial of Human Papillomavirus (HPV) testing for cervical cancer screening: trial design and preliminary results (HPV FOCAL Trial)

BACKGROUND

In the HPV FOCAL trial, we will establish the efficacy of hr-HPV DNA testing as a stand-alone screening test followed by liquid based cytology (LBC) triage of hr-HPV-positive women compared to LBC followed by hr-HPV triage with > or = CIN3 as the outcome.

METHODS/DESIGN

HPV-FOCAL is a randomized, controlled, three-armed study over a four year period conducted in British Columbia. It will recruit 33,000 women aged 25-65 through the province's population based cervical cancer screening program. Control arm: LBC at entry and two years, and combined LBC and hr-HPV at four years among those with initial negative results and hr-HPV triage of ASCUS cases; Two Year Safety Check arm: hr-HPV at entry and LBC at two years in those with initial negative results with LBC triage of hr-HPV positives; Four Year Intervention Arm: hr-HPV at entry and combined hr-HPV and LBC at four years among those with initial negative results with LBC triage of hr-HPV positive cases

DISCUSSION

To date, 6150 participants have a completed sample and epidemiologic questionnaire. Of the 2019 women enrolled in the control arm, 1908 (94.5%) were cytology negative. Women aged 25-29 had the highest rates of HSIL (1.4%). In the safety arm 92.2% of women were hr-HPV negative, with the highest rate of hr-HPV positivity found in 25-29 year old women (23.5%). Similar results were obtained in the intervention arm HPV FOCAL is the first randomized trial in North America to examine hr-HPV testing as the primary screen for cervical cancer within a population-based cervical cancer screening program.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number Register, ISRCTN79347302.

Brief research report: uncertainty-inducing and reassuring facts about HPV: a descriptive study of French Canadian women

We sought to describe information that makes women feel (1) uncertain and (2) reassured about their human papillomavirus (HPV) status and the potential health implications of an HPV DNA test result and (3) to examine information seeking after receiving their result. Thirty women (previously tested HPV negative) read factual information on HPV and cervical cancer and were asked which facts were uncertainty inducing and which were reassuring. Twenty-four facts reassured women of their HPV negative status, 11 facts made women feel uncertain, and 10 facts made them feel both. The most common reason for seeking information in the future was receiving a positive test result. The authors outline what specific facts about HPV health providers can emphasize to alleviate anxiety and encourage women to feel reassured of their low cancer risk following a negative test result.

Cervical dysplasia and associated risk factors in a juvenile detainee population

STUDY OBJECTIVE

Canada has licensed a human papilloma virus (HPV) vaccine for adolescent females, with the goal of decreasing the incidence of HPV infection and associated cervical cancer. This study identifies the juvenile detainee population as a high-risk group for HPV infection and therefore an important target for primary prevention.

DESIGN

A retrospective chart review.

SETTING

Sundance Juvenile Detention Center, Kingston, Ontario, Canada.

PARTICIPANTS

Female detainees admitted between 2003 and 2006.

MAIN OUTCOME MEASURES

Papanicolaou (Pap) test results, sexually transmitted infection (STI) rates, and associated risk factors were collected from 119 charts.

RESULTS

Of 57 recorded Pap smears, 46 (80.7%) were normal, 5 (8.8%) were reported as atypical squamous cells of unknown significance, and 6 (10.5%) were reported as low-grade squamous intraepithelial lesion. Of the women tested, 4% were positive for gonorrhea, 10% for chlamydia, 32% for bacterial vaginosis, and 5% for trichomonas; none were positive for syphilis. Of the girls, (91) (77%) had negative HIV and hepatitis B tests, two girls were hepatitis-C-positive, three had clinical evidence of genital herpes, and one showed evidence of pelvic inflammatory disease. There were 75 (63%) girls who reported sexual activity; 87% of them used contraception or protection of some kind, albeit inconsistently. Of these young females, 12 (10%) had engaged in prostitution and 13 (11%) had allegedly been raped or sexually assaulted.

CONCLUSIONS

Female juvenile detainees in Kingston, Ontario, have higher rates of STIs, associated risk factors, and abnormal Pap tests than the general female adolescent population. This new information confirms that this population is at risk for HPV infection and subsequent cervical cancer.