Cost-effectiveness of human papillomavirus DNA testing in the United Kingdom, The Netherlands, France, and Italy

Cost-effectiveness of 21 alternative cervical cancer screening strategies

OBJECTIVES

The aim of this study is to assess the cost-effectiveness of 21 alternative cervical cancer screening (CCS) strategies.

METHODS

A cohort simulation model was developed to determine from a health systems perspective the cost-effectiveness of the 21 alternative CCS strategies that incorporated combinations of Papanicolaou's smear test (PAP), liquid-based cytology (LBC) or human papillomavirus deoxyribonucleic acid (HPV-DNA) testing. The model was calibrated to categorize total costs into four budgetary authorities: testing, physician, inpatient, and outpatient services. Within each category, alternative screening strategies were contrasted in terms of their cost impacts and the percent change calculated within each category. Epidemiologic data and costs were derived from administrative health databases. Estimates of test characteristics and quality-adjusted life years (QALYs) were derived from available literature.

RESULTS

Three-year screening with PAP and HPV-DNA triage testing for women older than 30 years of age (3-year PAP+HPV+PAP-age) is less costly and more effective saving $16,078 per additional QALY gained. Although there was an associated net cost decrease of 4.2% driven by a reduction in testing and physician costs of 22.1% and 18.6%, respectively, there is a cost increase of 0.8% and 27.7% in inpatient and outpatient services, respectively.

CONCLUSION

There is economic evidence to support adopting 3-year PAP+HPV+PAP-age. Budgetary resources can potentially be shifted from testing and physician services to fund the additional resource requirements for inpatient and outpatient services.

Access of Black, Hispanic, and nonprivately insured women to liquid-based cytology, human papillomavirus DNA testing, and on-site colposcopy in the United States

OBJECTIVE

To determine whether patient race, ethnicity, or insurance status was associated with access to cervical cancer screening with liquid-based cytology (LBC) and with human papillomavirus (HPV) DNA testing and with access to on-site colposcopy at the provider's principal practice site.

MATERIALS AND METHODS

We conducted a nationally representative survey of clinicians in specialties that provide cervical cancer screening. Adjusted odds ratios (OR) were estimated for the associations between race, ethnicity, and insurance status of patients and provider use of LBC, HPV DNA testing, and on-site colposcopy.

RESULTS

Providers who cared for >or=20% Hispanic patients were less likely to use LBC (OR 0.60, 95% CI=0.42-0.84). Providers who cared for >or=25% black women (OR 0.71, 95% CI=0.51-0.98) and providers who cared for <75% privately insured patients (OR 0.66, 95% CI=0.46-0.95) were less likely to use HPV DNA testing. Providers who cared for <75% privately insured patients were less likely to have on-site colposcopy (OR 0.57, 95% CI=0.37-0.89), but those who cared for >or=20% Medicaid patients were more likely to have on-site colposcopy (OR 1.86, 95% CI=1.26-2.73).

CONCLUSIONS

Given the high rates of cervical cancer in minority women, access to cervical cancer screening and diagnostic follow-up must be ensured. It may also be beneficial to ensure affordable access to technologies such HPV DNA testing that increases the sensitivity of disease detection and to on-site colposcopy that facilitates follow-up of abnormal cytology.

Management of atypical squamous cells, low-grade squamous intraepithelial lesions, and cervical intraepithelial neoplasia 1

In the American Society for Colposcopy and Cervical Pathology 2006 Consensus Guidelines, several changes in the management of mildly abnormal cervical cytology and histology were made. The most notable changes involve the management of adolescents, pregnant women, and postmenopausal women. For adolescents, management of atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesions is conservative, eliminating the need for immediate colposcopy. For pregnant women, options have been made to allow for deferral of colposcopy until pregnancy completion, whereas for postmenopausal women, the new guidelines call for the option to rely on human papillomavirus DNA testing or repeat cytology to manage mild cytologic abnormalities. The guidelines for cervical intraepithelial neoplasia 1 now focus on conservative management. The goal of this article is to review the 2006 Guidelines, elaborating on the changes and providing the rationale for management decisions.

Modeling cervical cancer prevention in developed countries

Cytology-based screening has reduced cervical cancer mortality in countries able to implement, sustain and financially support organized programs that achieve broad coverage. These ongoing secondary prevention efforts considerably complicate the question of whether vaccination against human papillomavirus (HPV) types 16 and 18 should be introduced. Policy questions focus primarily on the target ages of vaccination, appropriate ages for a temporary "catch-up" program, possible revisions in screening policies to optimize synergies with vaccination, including the increased used of HPV DNA testing, and the inclusion of boys in the vaccination program. Decision-analytic models are increasingly being developed to simulate disease burden and interventions in different settings in order to evaluate the benefits and cost-effectiveness of primary and secondary interventions for informed decision-making. This article is a focused review on existing mathematical models that have been used to evaluate HPV vaccination in the context of developed countries with existing screening programs. Despite variations in model assumptions and uncertainty in existing data, pre-adolescent vaccination of girls has been consistently found to be attractive in the context of current screening practices, provided there is complete and lifelong vaccine protection and widespread vaccination coverage. Questions related to catch-up vaccination programs, potential benefits of other non-cervical cancer outcomes and inclusion of boys are subject to far more uncertainty, and results from these analyses have reached conflicting conclusions. Most analyses find that some catch-up vaccination is warranted but becomes increasingly unattractive as the catch-up age is extended, and vaccination of boys is unlikely to be cost-effective if reasonable levels of coverage are achieved in girls or coverage among girls can be improved. The objective of this review is to highlight points of consensus and qualitative themes, to discuss the areas of divergent findings, and to provide insight into critical decisions related to cervical cancer prevention.

Cost effectiveness of high-risk HPV DNA testing for cervical cancer screening in South Africa

OBJECTIVE

To determine the cost effectiveness of several cervical cancer screening strategies utilizing HPV testing in South Africa.

METHODS

We developed a lifetime Markov model of the costs, quality of life, and survival associated with screening and treating cervical cancer and its precursors. Screening strategies evaluated included: 1) conventional cytology, 2) cytology followed by HPV testing for triage of equivocal cytology, 3) HPV testing, 4) HPV testing followed by cytology for triage of HPV-positive women, and 5) co-screening with cytology and HPV testing. Primary outcome measures included quality-adjusted life-years saved (QALYs), incremental cost-effectiveness ratios, and lifetime risk of cervical cancer. Costs are in 2006 South African Rand (R).

RESULTS

In a cohort of 100,000 women, starting at age 30 and screening once every 10 years reduced the lifetime risk of cervical cancer by 13-52% depending on the screening strategy used, at an incremental cost of R13,000-R42,000 per QALY. When strategies were compared incrementally, cytology with HPV triage was less expensive and more effective than screening using cytology alone. HPV testing with the use of cytology triage was a more effective strategy and costs an additional R42,121 per QALY. HPV testing with colposcopy for HPV-positive women was the next most effective option at an incremental cost of R1541 per QALY. Simultaneous HPV testing and cytology co-screening was the most effective strategy and had an incremental cost of R25,414 per QALY.

CONCLUSIONS

In our model, HPV testing to screen for cervical cancer and its precursors is a cost-effective strategy in South Africa.

[Clinical efficacy of HPV DNA chip test in the era of HPV vaccination: 1,211 cases, a single institution study]

BACKGROUND

Human papillomavirus (HPV) prophylactic vaccines, bivalent types for HPV-16/18 with 70% prophylactic expectation, have been developed based on the genotypes found prevalent in the western countries, but little is known for those in Korea. Using a DNA chip test, we evaluated the clinical efficacy of HPV genotype based on cervical abnormalities.

METHODS

As the initial diagnostic tests, HPV DNA chip tests and Papanicolaou smear (PAP) were used for 1,211 subjects. Cervical colposcopy directed biopsies were performed for 626 among the 1,211 subjects within one month.

RESULTS

The most frequently found genotypes in all HPV-positive specimens (n=445) were HPV-16 (22.0%), 58 (13.9%), 52 (11.0%), 51 (9.0%), 56 (8.5%), and 18 (7.2%). HPV prevalence was significantly higher in specimens where PAP and biopsy results were closer to malignancy. The HPV genotype distribution of the histologically confirmed cervical high-grade squamous intraepithelial lesions (HSIL) or carcinoma cases showed HPV-16, 58, 52, 18, and 33, in descending order. The HPV DNA chip sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the detection of cervical HSIL or carcinoma were 76.9%, 70.1%, 72.1%, and 75.8%, respectively, Of these, the sensitivity and NPV were higher than those of PAP. PPV and NPV of HPV-16 were 90.5% and 60.7%, respectively, being the highest among the genotypes.

CONCLUSIONS

We confirmed that HPV-16 genotype was also very important for the diagnosis of HSIL and cervical carcinoma in Korea. However, contrary to the findings in the western countries, the prevalence of HPV-58 was higher than that of HPV-18. Moreover, as the other HPV genotype reports were rare in Korea, further studies are required with the HPV DNA chip test before the nationwide adoption of the vaccines.

Health and economic impact associated with a quadrivalent HPV vaccine in Italy

OBJECTIVE

The aim of this study was to determine the health impact and cost-effectiveness of introducing a human papillomavirus (HPV) vaccination programme with a quadrivalent vaccine alongside the existing cervical cancer screening programme in comparison to the current context in Italy.

METHODS

A US Markov model was adapted to the Italian context, assuming under base case 80% vaccine coverage rate, lifetime duration of protection in a cohort of girls aged 12 years and discount rates of 1.5% and 3% for health benefits and costs, respectively, and estimating direct medical costs.

RESULTS

The HPV vaccination in association with the current screening programme would allow to avoid 1432 cases of cervical cancer (-63.3%) and 513 deaths (-63.4%) compared to screening only, with an incremental cost-effectiveness ratio (ICER) of 9569 euros per additional quality-adjusted life-year (QALY) gained. The sensitivity analysis highlighted that this model was robust to all parameters presenting uncertainties as the ICERs ranged from 2,781 euros to 48,122 euros per QALY gained.

CONCLUSION

This study showed that HPV vaccination in adolescent girls would be a beneficial and cost-effective public health programme in Italy.

No increased risk for cervical cancer after a broader definition of a negative Pap smear

The definition of minimal relevant Pap smear abnormality is crucial for balancing the beneficial effects of screening (prevented mortality) with negative side-effects (the high positivity rate). After inflammation ceased to be defined as a borderline abnormal smear outcome in The Netherlands in 1996, the proportion of these smears dropped from 10% to less than 2%. Because this may have caused a loss in smear sensitivity, we analysed the changes in the incidence of cervical cancer after a negative Pap smear. All negative smears made at ages 30-64 in 1990-1995 (n = 1,546,252) and 1998-2006 (n = 3,552,716), registered in the national registry of histo- and cytopathology (PALGA), were followed for up to 9 years. During follow-up of the 1990-1995 smears, 377 women developed cervical cancer within 5,232,959 woman-years at risk, while during the follow-up of the 1998-2006 smears, 619 women developed cervical cancer within 11,210,675 woman-years at risk. The cumulative incidence after the definition change was not significantly higher than before: e.g. at 6 years, the cumulative incidence for smears made in 1990-1995 was 46 per 100,000 (95% CI: 41-52), and for smears in 1998-2006 was 48 per 100,000 (95% CI: 43-54), p = 0.59. The hazard ratio for 1998-2006 compared to 1990-1995 adjusted for age, number of previous negative smears and history of abnormalities was 0.90 (95% CI: 0.78-1.03). In The Netherlands, a setting with high-quality cytological screening, treating smears with only signs of inflammation as negative leads to a considerably lower positivity rate without increasing the risk for cervical cancer after a negative smear.

Cost-effectiveness of primarily human papillomavirus–based cervical cancer screening in settings with currently established Pap screening: A systematic review commissioned by the German Federal Ministry of Health

Objectives:The aim of this study was to summarize the current evidence for the cost-effectiveness of primarily human papillomavirus (HPV) -based cervical cancer screening in settings with already established Papanicolaou test (Pap) programs. Emphasis was placed on the German situation with annual Pap screening.

Methods:Medical, economic, and health technology assessment (HTA) databases were systematically searched for cost-effectiveness studies comparing HPV to Pap screening. Study data were extracted, standardized, and summarized in cost-effectiveness plots contrasting HPV strategies to Pap screening with 1-, 2-, 3-, and 5-years interval. For each Pap setting, the likelihood of cost-effective HPV screening was assessed depending on willingness-to-pay.

Results:We reviewed twelve decision-analytic cost-effectiveness models. Study results showed wide variation due to methodical heterogeneity. Data synthesis revealed that the cost-effectiveness of HPV screening depends on the interval of the established Pap screening strategy. In comparison with Pap screening every 2 years, only 25 percent of the HPV-based screening strategies were cost-effective. However, in comparison with Pap screening every 1, 3, or 5 years, 83 percent, 55 percent, and 92 percent of HPV screening strategies were cost-effective, respectively. Results for settings with annual Pap screening are based on models assuming 100 percent screening coverage.

Conclusions:The introduction of HPV-based screening programs is cost-effective if the screening interval of the established Pap program exceeds 2 years. In settings with biennial Pap screening, introduction of HPV-based screening is unlikely to be cost-effective. Results also suggest cost-effectiveness of HPV-based screening in settings with annual Pap screening; however, this finding should be confirmed under realistic screening adherence assumptions.

Cost-effectiveness of cervical cancer screening with human papillomavirus DNA testing and HPV-16,18 vaccination

BACKGROUND

The availability of human papillomavirus (HPV) DNA testing and vaccination against HPV types 16 and 18 (HPV-16,18) motivates questions about the cost-effectiveness of cervical cancer prevention in the United States for unvaccinated older women and for girls eligible for vaccination.

METHODS

An empirically calibrated model was used to assess the quality-adjusted life years (QALYs), lifetime costs, and incremental cost-effectiveness ratios (2004 US dollars per QALY) of screening, vaccination of preadolescent girls, and vaccination combined with screening. Screening varied by initiation age (18, 21, or 25 years), interval (every 1, 2, 3, or 5 years), and test (HPV DNA testing of cervical specimens or cytologic evaluation of cervical cells with a Pap test). Testing strategies included: 1) cytology followed by HPV DNA testing for equivocal cytologic results (cytology with HPV test triage); 2) HPV DNA testing followed by cytology for positive HPV DNA results (HPV test with cytology triage); and 3) combined HPV DNA testing and cytology. Strategies were permitted to switch once at age 25, 30, or 35 years.

RESULTS

For unvaccinated women, triennial cytology with HPV test triage, beginning by age 21 years and switching to HPV testing with cytology triage at age 30 years, cost $78,000 per QALY compared with the next best strategy. For girls vaccinated before age 12 years, this same strategy, beginning at age 25 years and switching at age 35 years, cost $41,000 per QALY with screening every 5 years and $188,000 per QALY screening triennially, each compared with the next best strategy. These strategies were more effective and cost-effective than screening women of all ages with cytology alone or cytology with HPV triage annually or biennially.

CONCLUSIONS

For both vaccinated and unvaccinated women, age-based screening by use of HPV DNA testing as a triage test for equivocal results in younger women and as a primary screening test in older women is expected to be more cost-effective than current screening recommendations.

Cervical cancer prevention--cervical screening: science in evolution

The incidence and mortality of cervical cancer in the United States has declined by more than 70% since the 1950s. This decline is attributed mainly to the introduction of Papanicolaou's test in the 1940s. Cervical cancer, however, remains the second most frequent of all female malignancies worldwide, with 80% of the cases occurring in resource-poor countries. This disparity is attributed primarily to the lack of screening and treatment of precancerous lesions. This article describes the traditional methods of screening for cervical cancer and innovative methods that might help overcome financial and cultural barriers to more widespread screening.

HPV and cervical cancer: screening or vaccination?

Following the demonstration of the superior validity of human papillomavirus (HPV) tests in screening for cervical cancer and the arrival of highly efficacious HPV 16 and 18 vaccines, cervical cancer prevention enters a time of sustainable introduction in developing countries. Multidisciplinary efforts and novel protocols are being developed, and challenging situations are being faced to make cervical cancer, still the number two cancer in women worldwide, an eradicable condition.

2006 consensus guidelines for the management of women with abnormal cervical screening tests

OBJECTIVE

To provide revised evidence-based consensus guidelines for managing women with abnormal cervical cancer screening test results.

PARTICIPANTS

A group of 146 experts, including representatives from 29 professional organizations, federal agencies, and national and international health organizations, met in Bethesda, MD, September 18-19, 2006, to develop the guidelines. MAJOR CHANGES IN GUIDELINES: The core recommendations for managing women with atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesions were changed minimally. Postcolposcopy management for women with these cytological abnormalities is now identical. Management recommendations for these conditions did change for "special populations," such as adolescents for whom a more conservative approach incorporating cytological follow-up for 2 years was approved. Core recommendations for managing women with high-grade squamous intraepithelial lesions and atypical glandular cells also underwent only minor modifications. More emphasis is placed on immediate "screen-and-treat" approaches when managing women with high-grade squamous intraepithelial lesion. Testing for high-risk human papillomavirus DNA is incorporated into the management of women with atypical glandular cells after their initial evaluation with colposcopy and endometrial sampling. The 2004 Interim Guidance for the use of human papillomavirus DNA testing as an adjunct to cervical cytology for screening in women 30 years and older was formally adopted with only very minor modifications.

CONCLUSIONS

The 2006 Consensus Guidelines reflect recent data from large clinical trials and advances in technology and are designed to assist clinicians of all subspecialties.

The impact of new technologies in cervical cancer screening: results of the recruitment phase of a large randomised controlled trial from a public health perspective

The decision to introduce liquid-based cytology (LBC) and HPV as screening tests involves criteria based on resource consumption. We used cross-sectional data at recruitment from the NTCC trial [ISRCTN81678807] on 28,000 women aged 35-60, randomised to receive a conventional Pap test or LBC plus HPV. We computed the resources employed to detect a CIN2+ with different screening strategies. In order to result in the same overall cost per CIN2+ detected as screening by conventional cytology, the unit cost of LBC used alone should be less than that of a conventional Pap while its unit cost may be up to 20% higher if HPV-triage for Atypical Squamous Cells of Undetermined Significance is applied together. With the same criterion the unit cost of HPV used alone may be about 20% higher than that of a Pap-test using a 1 pg/ml cut-off and over 40% higher using a 10 pg/ml cut-off. If HPV testing is applied with cytology-triage, a single HPV test may cost 20-30% more than a conventional Pap to result in the same overall cost per CIN2+ detected.

Modeling human papillomavirus and cervical cancer in the United States for analyses of screening and vaccination

Background

To provide quantitative insight into current U.S. policy choices for cervical cancer prevention, we developed a model of human papillomavirus (HPV) and cervical cancer, explicitly incorporating uncertainty about the natural history of disease.

Methods

We developed a stochastic microsimulation of cervical cancer that distinguishes different HPV types by their incidence, clearance, persistence, and progression. Input parameter sets were sampled randomly from uniform distributions, and simulations undertaken with each set. Through systematic reviews and formal data synthesis, we established multiple epidemiologic targets for model calibration, including age-specific prevalence of HPV by type, age-specific prevalence of cervical intraepithelial neoplasia (CIN), HPV type distribution within CIN and cancer, and age-specific cancer incidence. For each set of sampled input parameters, likelihood-based goodness-of-fit (GOF) scores were computed based on comparisons between model-predicted outcomes and calibration targets. Using 50 randomly resampled, good-fitting parameter sets, we assessed the external consistency and face validity of the model, comparing predicted screening outcomes to independent data. To illustrate the advantage of this approach in reflecting parameter uncertainty, we used the 50 sets to project the distribution of health outcomes in U.S. women under different cervical cancer prevention strategies.

Results

Approximately 200 good-fitting parameter sets were identified from 1,000,000 simulated sets. Modeled screening outcomes were externally consistent with results from multiple independent data sources. Based on 50 good-fitting parameter sets, the expected reductions in lifetime risk of cancer with annual or biennial screening were 76% (range across 50 sets: 69–82%) and 69% (60–77%), respectively. The reduction from vaccination alone was 75%, although it ranged from 60% to 88%, reflecting considerable parameter uncertainty about the natural history of type-specific HPV infection. The uncertainty surrounding the model-predicted reduction in cervical cancer incidence narrowed substantially when vaccination was combined with every-5-year screening, with a mean reduction of 89% and range of 83% to 95%.

Conclusion

We demonstrate an approach to parameterization, calibration and performance evaluation for a U.S. cervical cancer microsimulation model intended to provide qualitative and quantitative inputs into decisions that must be taken before long-term data on vaccination outcomes become available. This approach allows for a rigorous and comprehensive description of policy-relevant uncertainty about health outcomes under alternative cancer prevention strategies. The model provides a tool that can accommodate new information, and can be modified as needed, to iteratively assess the expected benefits, costs, and cost-effectiveness of different policies in the U.S.

Abnormal outcomes following cervical cancer screening: event duration and health utility loss

BACKGROUND

For decision analytic models, little empirical data are available from which to model the amount of time women spend with various cervical cytologic and histologic diagnoses following an abnormal Pap smear or the associated loss in quality-adjusted life-years (QALYs).

METHODS

The authors retrospectively examined administrative and cytopathology data for women with abnormal routine cervical smears within the Kaiser Permanente Northwest (Portland, OR) health plan during 1998. Data were examined through the conclusion of follow-up, with final outcomes categorized as cervical intraepithelial neoplasia (CIN) grades 1 to 3 (n = 201) or a false-positive result (n = 722) if no CIN or cancer was detected on follow-up. CIN outcomes were assigned according to the initial grade of dysplasia observed during the care episode in the primary analysis. The number of months spent with various cytologic and histologic diagnoses during the course of follow-up was tabulated, and utility weights were assigned using data from a prior study reporting time tradeoff scores for cervical health states.

RESULTS

The average total duration of follow-up was between 18 and 22 months for women with CIN, compared with 10 months for a false-positive Pap smear. The number of months spent with either an abnormal cytologic or histologic diagnosis was greater (P = 0.01) for women with CIN 1 (12.6 months) than CIN 3 (9.2 months), although this relationship was reversed for time spent receiving negative follow-up Pap smears and biopsies to rule out the presence of CIN and cancer. Total QALY losses per episode of care were estimated to be 0.11 for all 3 grades of CIN and 0.04 for a false-positive Pap smear.

CONCLUSIONS

The health and psychosocial burdens associated with follow-up for abnormal Pap smears translate into tangible QALY losses in a decision analytic context, with women receiving many months of follow-up and a variety of cytologic and histologic diagnoses over the course of a care episode.

An economic analysis of human papillomavirus triage for the management of women with atypical and abnormal Pap smear results in Germany

We developed decision-analytic models to determine the cost effectiveness of incorporating human papillomavirus (HPV) testing into the management of atypical and abnormal Pap smear results in Germany. The models compare three management strategies: (1) repeat Pap smear, (2) triage with HPV DNA testing, or (3) immediate treatment. The primary outcome measure is incremental cost per case of cervical intraepithelial neoplasia (CIN) 2+ detected and treated. The models take the perspective of the German health system. For patients with initial PapIIw, III, and IIId results, incremental cost effectiveness ratios for HPV triage versus repeat Pap smears are 2,232 euro, 815 euro, and 487 euro per additional case of CIN2+ detected and treated. In addition, the number of cases of CIN2+ detected and treated in a hypothetical population of 1,000 women increases from 17 to 35, 61 to 130, and 157 to 332 for each population, respectively. For patients with initial PapIII and IIId results, immediate treatment of 1,000 patients detects only four and 11 additional cases of CIN2+ versus HPV triage at incremental cost effectiveness ratios of 39,684 euro and 10,716 euro per case, respectively. For each of the populations evaluated, HPV triage is the most cost-effective management strategy versus either repeat Pap smear or immediate treatment.

The potential cost-effectiveness of prophylactic human papillomavirus vaccines in Canada

AIM

Clinical trials have shown prophylactic human papillomavirus (HPV) vaccines to be effective against infection and disease. We examined whether HPV vaccination has the potential to be cost-effective.

METHODS

A cohort model of the natural history of HPV was developed, which fits simultaneously Canadian age and type-specific data for infection, cervical intraepithelial neoplasia, cervical cancer (CC) and genital warts (GW). Quality-Adjusted Life-Years (QALYs) lost and costs were estimated using data from the literature.

RESULTS

Vaccinating 12-year-old girls (efficacy=95%, no waning, cost/course=CAN$ 400) against HPV-16/18 and HPV-6/11/16/18 is estimated to cost the health provider CAN$ 31,000 (80%CrI: 15,000-55,000) and CAN$ 21,000 (80%CrI: 11,000-33,000) per QALY-gained, respectively. Results were most sensitive to age at vaccination, duration of vaccine protection, vaccine cost and QALY-lost due to GW, and were least sensitive to the medical costs.

CONCLUSION

Vaccinating adolescent girls against HPV is likely to be cost-effective. The main benefit of vaccination will be in reducing CC mortality. However, unless screening is modified, the treatment costs saved through vaccination will be insignificant compared to the cost of HPV immunization.

A public health approach to cervical cancer control: considerations of screening and vaccination strategies

Cervical cancer remains a leading cause of cancer death among women living in low-resource settings. In the last 3 decades, cytologic screening has -in theory -been available and yet more than 6 million women have died of this preventable disease. The necessary resources, infrastructure, and technological expertise, together with the need for repeated screenings at regular intervals, make cytologic screening difficult to implement in poor countries. As noncytologic approaches for the detection of HPV, simple visual screening methods for anogenital lesions caused by HPV, and the availability of an HPV-16/18 vaccine will enhance the linkage between screening and treatment, multiple factors will need to be considered when designing new, or modifying existing prevention strategies. Countryspecific decisions regarding the best strategy for cervical cancer control will need to rely on data from many sources and take into account complex epidemiologic, economic, social, political, and cultural factors, and be made despite uncertainty and incomplete information. A rigorous decision analytic approach using computerbased modeling methods enables linkage of the knowledge gained from empirical studies to real-world situations. This chapter provides an introduction to these methods, reviews lessons learned from cost-effectiveness analyses of cervical cancer screening in developed and developing countries, and emphasizes important qualitative themes to consider in designing cervical cancer prevention policies.

Measures used in studies of informed decision making about cancer screening: a systematic review

Interventions to promote informed decision making (IDM) for cancer screening are increasingly common. The resulting body of literature provides an opportunity for a systematic review of measures in use. We searched standard databases for intervention trials and other studies of screening decisions and decision aids, finding 2,110 unique citations (most with abstracts) that we reduced to 104 full-text articles; 36 studies met inclusion criteria (prostate = 20, colorectal = 9, breast = 6, cervical = 1). Two independent coders abstracted data on study characteristics, constructs, and measures. Our findings revealed that most studies measured screening (or intention) and knowledge; fewer measured recommended IDM-related constructs and none measured all outcomes proposed for evaluating IDM interventions. Validity and reliability of measures received inadequate attention in study reports, and conceptual overlap exists among measures. Few IDM measures have been developed/carefully adapted from treatment measures and tested for cancer screening or in diverse populations. We recommend that new and in-progress studies emphasize outcomes beyond knowledge-participation in decision making according to personal preference, satisfaction with the process, and consistency between decisions and values. Also needed is better use of theory to guide conceptualization and operationalization of measures, greater attention to reliability and validity (particularly in diverse populations), more thorough reporting of sources and operating characteristics of measures, and increased emphasis and resources focused on these issues by funders, researchers, and journal editors.

An armamentarium of wart treatments

Patients and clinicians experience the frustration of cutaneous viral warts caused by infection with the human papilloma virus (HPV).Warts appear in various forms on different sites of the body and include common warts (verruca vulgaris), plane or flat warts, myrmecia, plantar warts, coalesced mosaic warts, filiform warts, periungual warts, anogenital warts (venereal or condyloma acuminata), oral warts and respiratory papillomas. Cervical infection with HPV is now known to cause cervical cancer if untreated. A review of the medical literature reveals a huge armamentarium of wart monotherapies and combination therapies. Official evidence-based guidelines exist for the treatment of warts, but very few of the reported treatments have been tested by rigorous blinded, randomized controlled trials.Therefore, official recommendations do not often include treatments with reportedly high success rates, but they should not be ignored when considering treatment options. It is the purpose of this review to provide a comprehensive overview of the wart treatment literature to expand awareness of the options available to practitioners faced with patients presenting with problematic warts.

Human Papillomavirus testing for the management of low-grade cervical abnormalities in the UK--Influence of age and testing strategy

BACKGROUND

The results of the UK pilot studies were encouraging with respect to the introduction of Human Papillomavirus (HPV) testing as a means to improve the management of low-grade cytological abnormalities. However, several important unresolved issues related to HPV triage remain, two of which are: what type of HPV test should be used and what age group should be targeted.

OBJECTIVES

To perform an evaluation of two commercial HPV detection tests and to correlate disease persistence and clearance with age and HPV status by the two tests.

STUDY DESIGN

We performed an evaluation of two commercial HPV tests in a cross-sectional analysis of 322 cervical cytology specimens with low-grade abnormalities. A subset of these specimens were then examined longitudinally, in order to correlate disease persistence and clearance with age and HPV status by the two detection tests.

RESULTS

The two tests performed similarly with respect to the longitudinal identification/prediction of high-grade cervical disease. Age did not appear to be a factor in determining which cases went on to manifest high-grade disease within 3 years of a low-grade result (p=0.678).

CONCLUSIONS

This study weakens the case for age-adjusted HPV triage of low-grade cervical abnormalities.

Chapter 19: Cost-effectiveness of cervical cancer screening

In the last two decades, computer-based models of cervical cancer screening have been used to evaluate the cost-effectiveness of different secondary prevention policies. Analyses in countries with existing screening programs have focused on identifying the optimal screening interval, ages for starting and stopping screening, and consideration of enhancements to conventional cytology, such as human papillomavirus (HPV)-DNA testing as a triage for equivocal results or as a primary screening test for women over the age of 30. Analyses in resource-poor settings with infrequent or no screening have focused on strategies that enhance the linkage between screening and treatment, consider noncytologic alternatives such as HPV-DNA testing, and target women between the ages of 35 and 45 for screening one, two, or three times per lifetime. Despite differences in methods and assumptions, this paper identifies the qualitative themes that are consistent among studies, and highlights important methodological challenges and high-priority areas for further work.

Cervical cancer in the developing world

In developed countries, systematic screening programmes have reduced the morbidity and mortality resulting from cervical cancer. Cytological methods of screening have been the mainstay in these countries. Nevertheless, there is scant evidence that cytology-based screening has had any effect in reducing cervical cancer mortality in less-developed countries. In fact, the challenge in less-developed countries is surpassed by the complex array of problems that go far beyond the introduction of simplified technologies. Currently, there are two main issues on this subject: the assessment of simpler screening methods, and the evaluation of different strategies regarding which women to target and the screening interval. Achieving high rates of coverage and compliance of the target population through high-quality procedures has remained the most difficult goal to achieve. Nevertheless, it is believed that creativity, flexibility and well-focused use of resources can reduce the inequitable burden of cervical cancer borne by women in poor countries.

Human papillomavirus testing as an optional screening tool in low-resource settings of Latin America: experience from the Latin American Screening study

Hybrid capture II (HC II) test for oncogenic human papillomaviruses (HPV) was carried out in a cohort of 4284 women at their first clinical visit. Overall prevalence of HPV was 17.1%, decreasing with age from 33.9% among women below 20 years to only 11.0% among those older than 41 years. HPV prevalence was significantly higher among current smokers (odds ratio [OR] = 1.31; 95% CI 1.1-1.6), in women with two or more lifetime sexual partners (OR = 1.9; 95% CI 1.6-2.4), and those women with two or more sexual partners during the past 12 months prior to examination (OR = 1.6; 95% CI 1.2-2.2). HPV detection increased in parallel with increasing cytologic abnormality, being highest in women with high-grade squamous intraepithelial lesion (P= 0.001). Specificity of the HPV test in detecting histologically confirmed cervical disease was 85% (95% CI 83.9-86.1). Sensitivity of the HPV test in detecting histologic abnormalities increased in parallel with disease severity, ranging from 51.5% for cervical intraepithelial neoplasia (CIN) 1 to 96.5% for CIN 3 and 100.0% for cancer, with respective decline of positive predictive value. These data suggest that HPV testing with HC II assay might be a viable screening tool among this population with relatively high prevalence of cervical disease.

Evaluation of cervical screening strategies with adjunct high-risk human papillomavirus testing for women with borderline or mild dyskaryosis

The management of women with a smear read as borderline/mild dyskaryosis (BMD) found by cervical cancer screening is still under discussion as only few of these cases are associated with high-grade lesions. To determine the optimal screening strategy for these women, a simulation model of cervical cancer development was used that is based on high-risk human papillomavirus (hrHPV) infection. The current strategy of repeat cytological testing at 6 and 18 months after BMD was compared to strategies with adjunct hrHPV testing. Calculations were done for both conventional and liquid-based cytology as the primary screening tool. In comparison to current screening, adjunct hrHPV testing was more effective in preventing cancer and more woman-friendly (reduction in colposcopy referrals with outcome < cervical intraepithelial neoplasia (CIN2) of up to 56% and in repeat smears of 30-100%). In combination with conventional cytology, cost-effective strategies were the ones in which a sample for high-risk human papillomavirus (hrHPV) testing is collected at a return visit within 1 month or in which hrHPV testing is restricted to repeat smears taken at 6 and 18 months. For these strategies, co-collection of samples for hrHPV testing at baseline is not necessary which has organizational and cost advantages. In combination with liquid-based cytology, it was cost-effective to perform a reflex hrHPV test at baseline from the liquid-based specimen. Liquid-based screening was more effective than conventional screening, but annual diagnosis costs were euro5 million higher (population size 16 million). In conclusion, our calculations indicate that implementation of hrHPV testing for the management of women with borderline or mild dyskaryosis (BMD) is feasible both in settings where conventional and liquid-based cytology is current practice.

HPV testing in cervical screening

High-risk human papillomavirus (hrHPV) bearing cervical intraepithelial neoplasia (CIN) is considered, as the real precursor lesion of cervical cancer and persistence of an hrHPV infection is necessary for the progression to cervical cancer. This knowledge warrants the use of hrHPV testing as an adjunct to cervical cytology in population-based screening programmes and for monitoring therapy efficacy of high-grade CIN lesions. Replacement of cytology by hrHPV testing altogether is considered, but for this to be (cost-) effective, accurate information about the specificity of the hrHPV test is required. Additional test systems that can be used to stratify women with a positive hrHPV test are HPV genotyping, viral load analysis and hrHPV mRNA analysis. The need for HPV genotyping of cervical smears is illustrated by the increased risk for high-grade cervical lesions associated with HPV types 16 and 18. In particular, for women who have normal but persistently (>1 year) HPV18-positive smears, endocervical curettage is suggested (evidently considering the age and possible future pregnancies of the respective woman) because HPV18 is associated with glandular lesions in the cervix, which are difficult to detect by cytology.