Estimating the cost of cervical cancer screening in five developing countries

E7-Targeted Nanotherapeutics for Key HPV Afflicted Cervical Lesions by Employing CRISPR/Cas9 and Poly (Beta-Amino Ester)

Introduction

Persistent HR-HPV (high-risk human papillomavirus) infection is the main cause of cervical cancer. The HPV oncogene E7 plays a key role in HPV tumorigenesis. At present, HPV preventive vaccines are not effective for patients who already have a cervical disease, and implementation of the recommended regular cervical screening is difficult in countries and regions lacking medical resources. Therefore, patients need medications to treat existing HPV infections and thus block the progression of cervical disease.

Methods

In this study, we developed nanoparticles (NPs) composed of the non-viral vector PBAE546 and a CRISPR/Cas9 recombinant plasmid targeting HPV16 E7 as a vaginal treatment for HPV infection and related cervical malignancies.

Results

Our NPs showed low toxicity and high biological safety both in vitro (cell line viability) and in vivo (various important organs of mice). Our NPs significantly inhibited the growth of xenograft tumors derived from cervical cancer cell lines in nude mice and significantly reversed the cervical epithelial malignant phenotype of HPV16 transgenic mice.

Conclusion

Our NPs have great potential to be developed as a drug for the treatment of HPV-related cervical cancer and precancerous lesions.

Cost-Effectiveness of Nasopharyngeal Carcinoma Screening With Epstein-Barr Virus Polymerase Chain Reaction or Serology in High-Incidence Populations Worldwide

BACKGROUND

The incidence of endemic Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC) varies considerably worldwide. In high-incidence regions, screening trials have been conducted. We estimated the mortality reduction and cost-effectiveness of EBV-based NPC screening in populations worldwide.

METHODS

We identified 380 populations in 132 countries with incident NPC and developed a decision-analytic model to compare 10 unique onetime screening strategies with no screening for men and women aged 50 years. Screening performance and the stage distribution of undiagnosed NPC were derived from a systematic review of prospective screening trials.

RESULTS

Screening was cost-effective in up to 14.5% of populations, depending on the screening strategy. These populations were limited to East Asia, Southeast Asia, and North Africa or were Asian, Pacific Islander, or Inuit populations in North America. A combination of serology and nasopharyngeal polymerase chain reaction was most cost-effective, but other combinations of serologic and/or plasma polymerase chain reaction screening were also cost-effective. The estimated reduction in NPC mortality was similar across screening strategies. For a hypothetical cohort of patients in China, the 10-year survival improved from 71.0% (95% confidence interval = 68.8% to 73.0%) without screening to a median of 86.3% (range = 83.5%-88.2%) with screening. This corresponded to a median 10-year reduction in NPC mortality of 52.9% (range = 43.1%-59.3%). Screening interval affected absolute mortality reduction and cost-effectiveness.

CONCLUSIONS

We observed decreased NPC mortality with EBV-based screening. Screening was cost-effective in many high-incidence populations and could be extended to men and women as early as age 40 years in select regions. These findings may be useful when choosing among local public health initiatives.

Nanoparticles Based on Poly (β-Amino Ester) and HPV16-Targeting CRISPR/shRNA as Potential Drugs for HPV16-Related Cervical Malignancy

Persistent high-risk HPV infection is the main cause of cervical cancer. The HPV oncogene E7 plays an important role in HPV carcinogenesis. Currently, HPV vaccines do not offer an effective treatment for women who already present with cervical disease, and recommended periodical cervical screenings are difficult to perform in countries and areas lacking medical resources. Our aim was to develop nanoparticles (NPs) based on poly (β-amino ester) (PBAE) and HPV16 E7-targeting CRISPR/short hairpin RNA (shRNA) to reduce the levels of HPV16 E7 as a preliminary form of a drug to treat HPV infection and its related cervical malignancy. Our NPs showed low toxicity in cells and mouse organs. By reducing the expression of HPV16 E7, our NPs could inhibit the growth of cervical cancer cells and xenograft tumors in nude mice, and they could reverse the malignant cervical epithelium phenotype in HPV16 transgenic mice. The performance of NPs containing shRNA is better than that of NPs containing CRISPR. HPV-targeting NPs consisting of PBAE and CRISPR/shRNA could potentially be developed as drugs to treat HPV infection and HPV-related cervical malignancy.

Cost analysis of Human Papillomavirus-related cervical diseases and genital warts in Swaziland

BACKGROUND

Human papillomavirus (HPV) has proven to be the cause of several severe clinical conditions on the cervix, vulva, vagina, anus, oropharynx and penis. Several studies have assessed the costs of cervical lesions, cervical cancer (CC), and genital warts. However, few have been done in Africa and none in Swaziland. Cost analysis is critical in providing useful information for economic evaluations to guide policymakers concerned with the allocation of resources in order to reduce the disease burden.

MATERIALS AND METHODS

A prevalence-based cost of illness (COI) methodology was used to investigate the economic burden of HPV-related diseases. We used a top-down approach for the cost associated with hospital care and a bottom-up approach to estimate the cost associated with outpatient and primary care. The current study was conducted from a provider perspective since the state bears the majority of the costs of screening and treatment in Swaziland. All identifiable direct medical costs were considered for cervical lesions, cervical cancer and genital warts, which were primary diagnoses during 2015. A mix of bottom up micro-costing ingredients approach and top-down approaches was used to collect data on costs. All costs were computed at the price level of 2015 and converted to dollars ($).

RESULTS

The total annual estimated direct medical cost associated with screening, managing and treating cervical lesions, CC and genital warts in Swaziland was $16 million. The largest cost in the analysis was estimated for treatment of high-grade cervical lesions and cervical cancer representing 80% of the total cost ($12.6 million). Costs for screening only represented 5% of the total cost ($0.9 million). Treatment of genital warts represented 6% of the total cost ($1million).

CONCLUSION

According to the cost estimations in this study, the economic burden of HPV-related cervical diseases and genital warts represents a major public health issue in Swaziland. Prevention of HPV infection with a national HPV immunization programme for pre-adolescent girls would prevent the majority of CC related deaths and associated costs.

The global burden of women's cancers: a grand challenge in global health

Every year, more than 2 million women worldwide are diagnosed with breast or cervical cancer, yet where a woman lives, her socioeconomic status, and agency largely determines whether she will develop one of these cancers and will ultimately survive. In regions with scarce resources, fragile or fragmented health systems, cancer contributes to the cycle of poverty. Proven and cost-effective interventions are available for both these common cancers, yet for so many women access to these is beyond reach. These inequities highlight the urgent need in low-income and middle-income countries for sustainable investments in the entire continuum of cancer control, from prevention to palliative care, and in the development of high-quality population-based cancer registries. In this first paper of the Series on health, equity, and women's cancers, we describe the burden of breast and cervical cancer, with an emphasis on global and regional trends in incidence, mortality, and survival, and the consequences, especially in socioeconomically disadvantaged women in different settings.

Cost-effectiveness of increasing cervical cancer screening coverage in the Middle East: An example from Lebanon

BACKGROUND

Most cervical cancer (CC) cases in Lebanon are detected at later stages and associated with high mortality. There is no national organized CC screening program so screening is opportunistic and limited to women who can pay out-of-pocket. Therefore, a small percentage of women receive repeated screenings while most are under-or never screened. We evaluated the cost-effectiveness of increasing screening coverage and extending intervals.

METHODS

We used an individual-based Monte Carlo model simulating HPV and CC natural history and screening. We calibrated the model to epidemiological data from Lebanon, including CC incidence and HPV type distribution. We evaluated cytology and HPV DNA screening for women aged 25-65years, varying coverage from 20 to 70% and frequency from 1 to 5years.

RESULTS

At 20% coverage, annual cytologic screening reduced lifetime CC risk by 14% and had an incremental cost-effectiveness ratio of I$80,670/year of life saved (YLS), far exceeding Lebanon's gross domestic product (GDP) per capita (I$17,460), a commonly cited cost-effectiveness threshold. By comparison, increasing cytologic screening coverage to 50% and extending screening intervals to 3 and 5years provided greater CC reduction (26.1% and 21.4, respectively) at lower costs compared to 20% coverage with annual screening. Screening every 5years with HPV DNA testing at 50% coverage provided greater CC reductions than cytology at the same frequency (23.4%) and was cost-effective assuming a cost of I$18 per HPV test administered (I$12,210/YLS); HPV DNA testing every 4years at 50% coverage was also cost-effective at the same cost per test (I$16,340). Increasing coverage of annual cytology was not found to be cost-effective.

CONCLUSION

Current practice of repeated cytology in a small percentage of women is inefficient. Increasing coverage to 50% with extended screening intervals provides greater health benefits at a reasonable cost and can more equitably distribute health gains. Novel HPV DNA strategies offer greater CC reductions and may be more cost-effective than cytology.

Economic Evaluation of Screening Strategies Combined with HPV Vaccination of Preadolescent Girls for the Prevention of Cervical Cancer in Vientiane, Lao PDR

Background

Several approaches to reduce the incidence of invasive cervical cancers exist. The approach adopted should take into account contextual factors that influence the cost-effectiveness of the available options.

Objective

To determine the cost-effectiveness of screening strategies combined with a vaccination program for 10-year old girls for cervical cancer prevention in Vientiane, Lao PDR.

Methods

A population-based dynamic compartment model was constructed. The interventions consisted of a 10-year old girl vaccination program only, or this program combined with screening strategies, i.e., visual inspection with acetic acid (VIA), cytology-based screening, rapid human papillomavirus (HPV) DNA testing, or combined VIA and cytology testing. Simulations were run over 100 years. In base-case scenario analyses, we assumed a 70% vaccination coverage with lifelong protection and a 50% screening coverage. The outcome of interest was the incremental cost per Disability-Adjusted Life Year (DALY) averted.

Results

In base-case scenarios, compared to the next best strategy, the model predicted that VIA screening of women aged 30–65 years old every three years, combined with vaccination, was the most attractive option, costing 2 544 international dollars (I$) per DALY averted. Meanwhile, rapid HPV DNA testing was predicted to be more attractive than cytology-based screening or its combination with VIA. Among cytology-based screening options, combined VIA with conventional cytology testing was predicted to be the most attractive option. Multi-way sensitivity analyses did not change the results. Compared to rapid HPV DNA testing, VIA had a probability of cost-effectiveness of 73%. Compared to the vaccination only option, the probability that a program consisting of screening women every five years would be cost-effective was around 60% and 80% if the willingness-to-pay threshold is fixed at one and three GDP per capita, respectively.

Conclusions

A VIA screening program in addition to a girl vaccination program was predicted to be the most attractive option in the health care context of Lao PDR. When compared with other screening methods, VIA was the primary recommended method for combination with vaccination in Lao PDR.

The economic evaluation of human papillomavirus vaccination strategies against cervical cancer in women in Lao PDR: a mathematical modelling approach

BACKGROUND

Cervical cancer, a preventable disease, is the third leading cause of cancer morbidity and mortality in the Lao People's Democratic Republic (Lao PDR). Since many cervical cancers are linked to human papilloma virus (HPV) infection, vaccination against this virus may lead to a reduction in these types of cancer. The study described here is the first to compare the cost-effectiveness of different HPV vaccination options in Lao PDR.

METHODS

A dynamic compartment model was created. The model included routine screening activities already in place, as well as theoretical interventions that included a 10-year old girl-only vaccination programme combined with/without a 10-year old boy vaccination programme and/or a catch-up component. The simulation was run over 100 years. In base case analyses, we assumed 70 % vaccination coverage with lifelong protection and 100 % efficacy against HPV types 16/18. The outcomes of interest were the incremental cost per Disability-Adjusted Life Year (DALY) averted.

RESULTS

In base case analyses, according to the WHO definition of cost-effectiveness thresholds, vaccinating 10-year-old girls was very cost-effective. Adding a catch-up vaccination element for females aged 11-25 years was also very cost-effective, costing 1559 international dollars (I$) per DALY averted. Increasing the age limit of the catch-up vaccination component to 75 years old showed that this remained a cost-effective option (I$ 5840 per DALY averted). Adding a vaccination programme for 10-year-old boys was not found to be cost-effective unless a short time simulation (30 years or less) was considered, along with a catch-up vaccination component for both males and females.

CONCLUSIONS

Adding a catch-up female vaccination component is more attractive than adding a 10-year-old boy vaccination component.

Cervical cancer prevention and treatment research in Africa: a systematic review from a public health perspective

BACKGROUND

Women living in Africa experience the highest burden of cervical cancer. Research and investment to improve vaccination, screening, and treatment efforts are critically needed. We systematically reviewed and characterized recent research within a broader public health framework to organize and assess the range of cervical cancer research in Africa.

METHODS

We searched online databases and the Internet for published articles and cervical cancer reports in African countries. Inclusion criteria included publication between 2004 and 2014, cervical cancer-related content pertinent to one of the four public health categories (primary, secondary, tertiary prevention or quality of life), and conducted in or specifically relevant to countries or regions within the African continent. The study design, geographic region/country, focus of research, and key findings were documented for each eligible article and summarized to illustrate the weight and research coverage in each area. Publications with more than one focus (e.g. secondary and tertiary prevention) were categorized by the primary emphasis of the paper. Research specific to HIV-infected women or focused on feasibility issues was delineated within each of the four public health categories.

RESULTS

A total of 380 research articles/reports were included. The majority (54.6 %) of cervical cancer research in Africa focused on secondary prevention (i.e., screening). The number of publication focusing on primary prevention (23.4 %), particularly HPV vaccination, increased significantly in the past decade. Research regarding the treatment of precancerous lesions and invasive cervical cancer is emerging (17.6 %), but infrastructure and feasibility challenges in many countries have impeded efforts to provide and evaluate treatment. Studies assessing aspects of quality of life among women living with cervical cancer are severely limited (4.1 %). Across all categories, 11.3 % of publications focused on cervical cancer among HIV-infected women, while 17.1 % focused on aspects of feasibility for cervical cancer control efforts.

CONCLUSIONS

Cervical cancer research in African countries has increased steadily over the past decade, but more is needed. Tertiary prevention (i.e. treatment of disease with effective medicine) and quality of life of cervical cancer survivors are two severely under-researched areas. Similarly, there are several countries in Africa with little to no research ever conducted on cervical cancer.

Oxytocin in Uniject Disposable Auto-Disable Injection System versus Standard Use for the Prevention of Postpartum Hemorrhage in Latin America and the Caribbean: A Cost-Effectiveness Analysis

Postpartum hemorrhage (PPH) is a leading cause of maternal death. Despite strong evidence showing the efficacy of routine oxytocin in preventing PPH, the proportion of women receiving it after delivery is still below 100%. The Uniject injection system prefilled with oxytocin (Uniject) has the potential advantage, due to its ease of use, to increase oxytocin utilization rates. We aimed to assess its cost-effectiveness in Latin America and the Caribbean (LAC). We used an epidemiological model to estimate: a) the impact of replacing oxytocin in ampoules with Uniject on the incidence of PPH, quality-adjusted life years (QALYs) and costs from a health care system perspective, and b) the minimum increment in oxytocin utilization rates required to make Uniject a cost-effective strategy. A consensus panel of LAC experts was convened to quantify the expected increase in oxytocin rates as a consequence of making Uniject available. Deterministic and probabilistic sensitivity analyses were performed. In the base case, the incremental cost of Uniject with respect to oxytocin in ampoules was estimated to be USD 1.00 (2013 US dollars). In the cost-effectiveness analysis, Uniject ranged from being cost-saving (in 8 out of 30 countries) to having an incremental cost-effectiveness ratio (ICER) of USD 8,990 per QALY gained. In most countries these ICERs were below one GDP per capita. The minimum required increment in oxytocin rates to make Uniject a cost-effective strategy ranged from 1.3% in Suriname to 16.2% in Haiti. Switching to Uniject could prevent more than 40,000 PPH events annually in LAC. Uniject was cost-saving or very cost-effective in almost all countries. Even if countries can achieve only small increases in oxytocin rates by incorporating Uniject, this strategy could be considered a highly efficient use of resources. These results were robust in the sensitivity analysis under a wide range of assumptions.

HIV, tuberculosis, and noncommunicable diseases: what is known about the costs, effects, and cost-effectiveness of integrated care?

Unprecedented investments in health systems in low- and middle-income countries (LMICs) have resulted in more than 8 million individuals on antiretroviral therapy. Such individuals experience dramatically increased survival but are increasingly at risk of developing common noncommunicable diseases (NCDs). Integrating clinical care for HIV, other infectious diseases, and NCDs could make health services more effective and provide greater value. Cost-effectiveness analysis is a method to evaluate the clinical benefits and costs associated with different health care interventions and offers guidance for prioritization of investments and scale-up, especially as resources are increasingly constrained. We first examine tuberculosis and HIV as 1 example of integrated care already successfully implemented in several LMICs; we then review the published literature regarding cervical cancer and depression as 2 examples of NCDs for which integrating care with HIV services could offer excellent value. Direct evidence of the benefits of integrated services generally remains scarce; however, data suggest that improved effectiveness and reduced costs may be attained by integrating additional services with existing HIV clinical care. Further investigation into clinical outcomes and costs of care for NCDs among people living with HIV in LMICs will help to prioritize specific health care services by contributing to an understanding of the affordability and implementation of an integrated approach.

Estimation of the costs of cervical cancer screening, diagnosis and treatment in rural Shanxi Province, China: a micro-costing study

Background

Cost estimation is a central feature of health economic analyses. The aim of this study was to use a micro-costing approach and a societal perspective to estimate aggregated costs associated with cervical cancer screening, diagnosis and treatment in rural China.

Methods

We assumed that future screening programs will be organized at a county level (population ~250,000), and related treatments will be performed at county or prefecture hospitals; therefore, this study was conducted in a county and a prefecture hospital in Shanxi during 2008–9. Direct medical costs were estimated by gathering information on quantities and prices of drugs, supplies, equipment and labour. Direct non-medical costs were estimated via structured patient interviews and expert opinion.

Results

Under the base case assumption of a high-volume screening initiative (11,475 women screened annually per county), the aggregated direct medical costs of visual inspection, self-sampled careHPV (Qiagen USA) screening, clinician-sampled careHPV, colposcopy and biopsy were estimated as US$2.64,$7.49,$7.95,$3.90 and $5.76, respectively. Screening costs were robust to screening volume (<5% variation if 2,000 women screened annually), but costs of colposcopy/biopsy tripled at the lower volume. Direct medical costs of Loop Excision, Cold-Knife Conization and Simple and Radical Hysterectomy varied from $61–544, depending on the procedure and whether conducted at county or prefecture level. Direct non-medical expenditure varied from $0.68–$3.09 for screening/diagnosis and $83–$494 for pre-cancer/cancer treatment.

Conclusions

Diagnostic costs were comparable to screening costs for high-volume screening but were greatly increased in lower-volume situations, which is a key consideration for the scale-up phase of new programs. The study’s findings will facilitate cost-effectiveness evaluation and budget planning for cervical cancer prevention initiatives in China.

Estimation of the costs of cervical cancer screening, diagnosis and treatment in rural Shanxi Province, China: a micro-costing study

BACKGROUND

Cost estimation is a central feature of health economic analyses. The aim of this study was to use a micro-costing approach and a societal perspective to estimate aggregated costs associated with cervical cancer screening, diagnosis and treatment in rural China.

METHODS

We assumed that future screening programs will be organized at a county level (population ~250,000), and related treatments will be performed at county or prefecture hospitals; therefore, this study was conducted in a county and a prefecture hospital in Shanxi during 2008-9. Direct medical costs were estimated by gathering information on quantities and prices of drugs, supplies, equipment and labour. Direct non-medical costs were estimated via structured patient interviews and expert opinion.

RESULTS

Under the base case assumption of a high-volume screening initiative (11,475 women screened annually per county), the aggregated direct medical costs of visual inspection, self-sampled careHPV (Qiagen USA) screening, clinician-sampled careHPV, colposcopy and biopsy were estimated as US$2.64,$7.49,$7.95,$3.90 and $5.76, respectively. Screening costs were robust to screening volume (<5% variation if 2,000 women screened annually), but costs of colposcopy/biopsy tripled at the lower volume. Direct medical costs of Loop Excision, Cold-Knife Conization and Simple and Radical Hysterectomy varied from $61-544, depending on the procedure and whether conducted at county or prefecture level. Direct non-medical expenditure varied from $0.68-$3.09 for screening/diagnosis and $83-$494 for pre-cancer/cancer treatment.

CONCLUSIONS

Diagnostic costs were comparable to screening costs for high-volume screening but were greatly increased in lower-volume situations, which is a key consideration for the scale-up phase of new programs. The study's findings will facilitate cost-effectiveness evaluation and budget planning for cervical cancer prevention initiatives in China.

Health and economic impact of HPV 16/18 vaccination and cervical cancer screening in Eastern Africa

Eastern Africa has the world's highest cervical cancer incidence and mortality rates. We used epidemiologic data from Kenya, Mozambique, Tanzania, Uganda, and Zimbabwe to develop models of HPV-related infection and disease. For each country, we assessed HPV vaccination of girls before age 12 followed by screening with HPV DNA testing once, twice, or three times per lifetime (at ages 35, 40, 45). For women over age 30, we assessed only screening (with HPV DNA testing up to three times per lifetime or VIA at age 35). Assuming no waning immunity, mean reduction in lifetime cancer risk associated with vaccination ranged from 36 to 45%, and vaccination followed by screening once per lifetime at age 35 with HPV DNA testing ranged from 43 to 51%. For both younger and older women, the most effective screening strategy was HPV DNA testing three times per lifetime. Provided the cost per vaccinated girl was less than I$10 (I$2 per dose), vaccination had an incremental cost-effectiveness ratio [I$ (international dollars)/year of life saved (YLS)] less than the country-specific per capita GDP, a commonly cited heuristic for "very cost-effective" interventions. If the cost per vaccinated girl was between I$10 (I$2 per dose) and I$25 (I$5 per dose), vaccination followed by HPV DNA testing would save the most lives and would be considered good value for public health dollars. These results should be used to catalyze design and evaluation of HPV vaccine delivery and screening programs, and contribute to a dialogue on financing HPV vaccination in poor countries.

Management of Precancerous Lesions of the Uterine Cervix according to Demographic Data

Aims. Worldwide, cervical cancer is the fifth most deadly cancer in women, but screening prevents cancer by detecting precancerous lesions. The purpose of this study is to present the treatment profile for precancerous lesions of the uterine cervix, according to demographic data. Methods. An annual retrospective study was conducted in two public primary health care centres in Greece. The total number of Pap smears and colposcopies performed as well as the management of women with cervical intraepithelial neoplasia was collected and analysed. Results. Demographic characteristics and correlations with levels of Cervical Intraepithelial Neoplasia (CIN) and treatment path are presented. For each case, we noted the patients' age, the marital and educational status, and the professional and insurance type. From a total of 238 diagnostic procedures, 118 (49.5%) showed precancerous lesions, 83.3% of these were high grade while 16.7% were low grade. Conclusions. This study provides an estimate of the extensiveness of precancerous lesions of the uterine cervix. Management of CIN should be accounted for when balancing the benefits and unfavourable effects of this screening.

SUPPORT Tools for evidence-informed health Policymaking (STP) 12: Finding and using research evidence about resource use and costs

This article is part of a series written for people responsible for making decisions about health policies and programmes and for those who support these decision makers.

In this article, we address considerations about resource use and costs. The consequences of a policy or programme option for resource use differ from other impacts (both in terms of benefits and harms) in several ways. However, considerations of the consequences of options for resource use are similar to considerations related to other impacts in that policymakers and their staff need to identify important impacts on resource use, acquire and appraise the best available evidence regarding those impacts, and ensure that appropriate monetary values have been applied. We suggest four questions that can be considered when assessing resource use and the cost consequences of an option. These are: 1. What are the most important impacts on resource use? 2. What evidence is there for important impacts on resource use? 3. How confident is it possible to be in the evidence for impacts on resource use? 4. Have the impacts on resource use been valued appropriately in terms of their true costs?

Benefits, cost requirements and cost-effectiveness of the HPV16,18 vaccine for cervical cancer prevention in developing countries: policy implications

Approximately 70% of cases of cervical cancer worldwide are caused by genotypes 16 and 18 of human papillomavirus (HPV), which is sexually transmitted. With the availability of an effective vaccine against these HPV types, there is real hope for reducing the global burden of cervical cancer in developing countries. Stakeholders faced with decisions about where to invest money to improve health must consider the burden of disease caused by cervical cancer relative to other priorities and the comparative benefits of different interventions. We conducted a series of analyses to obtain information for agencies drafting immunisation policy recommendations, financing coordination mechanisms, and country decision-makers on the benefits, cost requirements and cost-effectiveness of the HPV16,18 vaccine. We found that making an HPV16,18 vaccine accessible to 70% of young adolescent girls in 72 of the poorest countries, China, Thailand, and all of Latin America and the Caribbean, could prevent the future deaths of more than four million women vaccinated over the next decade. Provided the cost per vaccinated girl is less than $10-$25, adolescent HPV16,18 vaccination would be cost-effective even in relatively poor countries. Concerns about financial costs and affordability highlight the need for lowering vaccine prices, cost-efficient mechanisms for delivery of vaccinations to adolescents, and creative sources of financing.

Mathematical models of cervical cancer prevention in the Asia Pacific region

Using population-based and epidemiologic data for 25 countries in Asia (22 GAVI-Alliance eligible countries, Thailand, China and Japan), a model-based approach was used to estimate averted cervical cancer cases and deaths, disability-adjusted life years (DALYs) and incremental cost-effectiveness ratios (I$/DALY averted) for vaccination of young adolescent girls against human papillomavirus (HPV) types 16 and 18. Absolute reduction in lifetime cancer risk varied between countries, depending on incidence, proportion attributable to HPV-16 and -18, and population age-structure; for example, with 70% coverage, cancer reduction was 57% in Indonesia, whereas in Cambodia, it was 49%. Screening of women over age 30 three times per lifetime, after vaccinating them as pre-adolescents, is expected to provide an additional 20% to 30% mortality reduction. Of the 22 GAVI-Alliance eligible countries, India, Bangladesh, Vietnam and Indonesia account for 87% of the total DALYs averted. Assuming a cost per vaccinated girl of I$10 ($2 per dose), the cost per DALY averted is less than I$250 in 18 of 22 countries. Assuming a cost per vaccinated girl of I$25, the cost per DALY averted is I$1,360 in China compared with I$250 in Thailand, reflecting the greater number of girls that need to be vaccinated to prevent a death from cervical cancer in China. Vaccine price has an even greater effect on predicted affordability. For the 22 GAVI Alliance-eligible countries, vaccinating 5 consecutive birth cohorts at 70% coverage would cost over US $500 million versus almost US $1.3 billion at per dose costs of $2 and $5, respectively. Including China and Thailand would add US $251 million to US $1.4 billion at per dose prices of $2 and $12.25, respectively. In the countries we assessed, vaccination of young adolescent girls against HPV-16 and -18 could be very cost-effective if the cost per vaccinated girl is less than I$10-I$25; for it to be affordable, however, even with financing assistance, vaccine prices may need to be even lower.

Human papillomavirus and cervical cancer

Cervical cancer is the second most common cancer in women worldwide, and knowledge regarding its cause and pathogenesis is expanding rapidly. Persistent infection with one of about 15 genotypes of carcinogenic human papillomavirus (HPV) causes almost all cases. There are four major steps in cervical cancer development: infection of metaplastic epithelium at the cervical transformation zone, viral persistence, progression of persistently infected epithelium to cervical precancer, and invasion through the basement membrane of the epithelium. Infection is extremely common in young women in their first decade of sexual activity. Persistent infections and precancer are established, typically within 5-10 years, from less than 10% of new infections. Invasive cancer arises over many years, even decades, in a minority of women with precancer, with a peak or plateau in risk at about 35-55 years of age. Each genotype of HPV acts as an independent infection, with differing carcinogenic risks linked to evolutionary species. Our understanding has led to improved prevention and clinical management strategies, including improved screening tests and vaccines. The new HPV-oriented model of cervical carcinogenesis should gradually replace older morphological models based only on cytology and histology. If applied wisely, HPV-related technology can minimise the incidence of cervical cancer, and the morbidity and mortality it causes, even in low-resource settings.

Vaccines against human papillomavirus: perspectives for controlling cervical cancer

Prophylactic vaccines against human papillomavirus (HPV) are on the market and will certainly reduce the incidence of genital warts and the risk of developing cervical cancer. In addition, they will contribute to reducing anal as well as head and neck cancers. However, effort should be made in the short term in order for these vaccines to have a real impact in the developing world, where almost 80% of cervical cancer cases occur. Since the available vaccines include only two of the HPV types found in cancers (approximately 70%), improvements in current mass screening programs - with the use of molecular techniques - must be made, particularly in developing countries. Therapeutic vaccines have been designed to control advanced lesions and residual illness and, although success has usually been obtained in animal models, clinical studies have not yet provided the anticipated results. Finally, the next generations of prophylactic HPV vaccines will probably include subunit vaccines, transgenic bacteria and plants, among others, and could represent useful and cheaper alternatives for reducing cervical cancer, particularly in the developing world.

Cost-effectiveness of HPV 16, 18 vaccination in Brazil

We use an empirically calibrated model to estimate the cost-effectiveness of cervical cancer prevention in Brazil, a country with a high cervical cancer burden. Assuming 70% coverage, HPV 16, 18 vaccination of adolescent girls is expected to reduce the lifetime risk of cancer by approximately 42.7% (range, 33.2-53.5%); screening three times per lifetime is expected to reduce risk by 21.9-30.7% depending on the screening test, and a combined approach of vaccination and screening is expected to reduce cancer risk by a mean of 60.8% (range, 52.8-70.1%). In Brazil; provided the cost per vaccinated woman is less than I$ 25, implying a per dose cost of approximately I$ 5, vaccination before age 12, followed by screening three times per lifetime between ages 35 and 45, would be considered very cost-effective using the country's per capita gross domestic product as a cost-effectiveness threshold. Assuming a coverage rate of 70%, this strategy would be expected to prevent approximately 100,000 cases of invasive cervical cancer over a 5-year period. Vaccination strategies identified as cost-effective may be unaffordable in countries with similar socioeconomic profiles as Brazil without assistance; these results can provide guidance to the global community by identifying health investments of highest priority and with the greatest promise.