Cost-effective interventions for breast cancer, cervical cancer, and colorectal cancer: new results from WHO-CHOICE

A real-time deep learning-based system for colorectal polyp size estimation by white-light endoscopy: development and multicenter prospective validation

BACKGROUND

The choice of polypectomy device and surveillance intervals for colorectal polyps are primarily decided by polyp size. We developed a deep learning-based system (ENDOANGEL-CPS) to estimate colorectal polyp size in real time.

METHODS

ENDOANGEL-CPS calculates polyp size by estimating the distance from the endoscope lens to the polyp using the parameters of the lens. The depth estimator network was developed on 7297 images from five virtually produced colon videos and tested on 730 images from seven virtual colon videos. The performance of the system was first evaluated in nine videos of a simulated colon with polyps attached, then tested in 157 real-world prospective videos from three hospitals, with the outcomes compared with that of nine endoscopists over 69 videos. Inappropriate surveillance recommendations caused by incorrect estimation of polyp size were also analyzed.

RESULTS

The relative error of depth estimation was 11.3% (SD 6.0%) in successive virtual colon images. The concordance correlation coefficients (CCCs) between system estimation and ground truth were 0.89 and 0.93 in images of a simulated colon and multicenter videos of 157 polyps. The mean CCC of ENDOANGEL-CPS surpassed all endoscopists (0.89 vs. 0.41 [SD 0.29]; P<0.001). The relative accuracy of ENDOANGEL-CPS was significantly higher than that of endoscopists (89.9% vs. 54.7%; P<0.001). Regarding inappropriate surveillance recommendations, the system's error rate is also lower than that of endoscopists (1.5% vs. 16.6%; P<0.001).

CONCLUSIONS

ENDOANGEL-CPS could potentially improve the accuracy of colorectal polyp size measurements and size-based surveillance intervals.

Changing Colorectal Cancer Trends in Asians: Epidemiology and Risk Factors

Once an infrequent disease in parts of Asia, the rate of colorectal cancer in recent decades appears to be steadily increasing. Colorectal cancer represents one of the most important causes of cancer mortality worldwide, including in many regions in Asia. Rapid changes in socioeconomic and lifestyle habits have been attributed to the notable increase in the incidence of colorectal cancers in many Asian countries. Through published data from the International Agency for Cancer Research (IARC), we utilized available continuous data to determine which Asian nations had a rise in colorectal cancer rates. We found that East and South East Asian countries had a significant rise in colorectal cancer rates. Subsequently, we summarized here the known genetics and environmental risk factors for colorectal cancer among populations in this region as well as approaches to screening and early detection that have been considered across various countries in the region.

Challenges in the management of colorectal cancer in low- and middle-income countries

AIM

This narrative review aims to describe colorectal cancer (CRC) management landscape in low- and middle-income countries (LMICs), presenting the most recent and relevant papers on the topic. As a secondary aim, the authors suggest new ways of improving CRC patient care in LMICs.

BACKGROUND

Several studies show that the incidence of colon cancer in low- and middle-income countries (LMICs) is rising. In addition to the increasing incidence, lack of early detection and impeded access to optimal multidisciplinary treatment may worsen survival outcomes.

CONCLUSION

Developing quality diagnostic services in the proper health context is crucial for early diagnosis and successful therapy of CRC patients, and applying a resource-sensitive approach to prioritize essential treatments based on effectiveness and cost-effectiveness is key to overcoming barriers in LMICs, with clinical research collaborations between high-income countries (HICs) and LMICs being a helpful strategy to improve health indicators and prevent the burnout of health workers.

Practical notes on the current ESMO consensus guidelines for the management of patients with metastatic colorectal cancer in resource-constrained environments of low- to middle-income countries

Letter (no abstract).

Serum trace element levels of gastrointestinal cancer patients in an endemic upper gastrointestinal cancer region

Gastrointestinal (GI) cancers are an important cause of the death rate in Turkey and in the world. Especially upper (esophageal and gastric) GI cancers are the leading types of cancer by 20-27% in Eastern Turkey. Trace elements are involved in many physiological and metabolic processes in the human body. Recent studies suggest that the increase or decrease of trace elements in the body may be related to the formation and development of many diseases such as cancers, diabetes mellitus and cardiovascular diseases etc. METHOD AND MATERIALS: In this study some trace elements; cadmium (Cd), cobalt (Co), Copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), lead (Pb), zinc (Zn) concentrations were investigated in the blood serums of esophageal, gastric and colon cancer patients and healthy controls in Van city area, an endemic upper (esophageal and gastric) GI region of Eastern Turkey. The analysis of the elements was realized with a flame atomic absorption spectrophotometer (FAAS). RESULTS: Mean serum levels of Cd and Ni in esophageal and gastric cancer patients were very significantly lower compared to controls (p < 0.001 and < 0.005). In addition, the mean serum Co level of esophageal cancer patients was very significantly lower than in controls and gastric cancer patients (p < 0.002). Also, the mean serum levels of Fe and Mn in all (esophageal, gastric and colon) cancer groups were very significantly lower than in controls (p < 0.001 and 0.002). Mean serum levels of Cu, Mg, Pb and Zn were not significantly different in all cancer patients compared to controls. CONCLUSION: We have detected the deficiency of five trace elements (Fe, Mn, Cd, Ni, Co) in esophageal, gastric and colon cancer patients. The deficiencies of trace elements may be due to malign over consumption of the nutrients and to the malnutrition of the advanced cancer patients. Nutritional therapy rich in trace elements should be considered as one of the strategies to fight against cancers.

Tin-loaded mesoporous silica nanoparticles: Antineoplastic properties and genotoxicity assessment

Nanotechnology has immensely advanced the field of cancer diagnostics and treatment by introducing potential delivery vehicles as carriers for drugs or therapeutic agents. In due course, mesoporous silica nanoparticles (MSNs) have emerged as excellent vehicles for delivering drugs, biomolecules, and biomaterials, attributed to their solid framework and porosity providing a higher surface area for decorating with various functional ligands. Recently, the metal tin (Sn) has gained huge importance in cancer research owing to its excellent cytotoxicity and ability to kill cancer cells. In the present work, we synthesized MSNs, conjugated them with organotin compounds, and characterized them using various physicochemical techniques. Subsequently, the biological evaluation of MSN (S1), MSN-MP (S2) and tin-conjugated MSNs (S3: MSN-MP-SnPh3) (MP = 3-mercaptopropyltriethoxysilane) revealed that these nanoconjugates induced cytotoxicity, necrosis, and apoptosis in MCF-7 cells. Moreover, these nanoconjugates exhibited anti-angiogenic properties as demonstrated in the chick embryo model. The increase of reactive oxygen species (ROS) was found as a one of the plausible mechanisms underlying cancer cell cytotoxicity induced by these nanoconjugates, encouraging their application for the treatment of cancer. The tin-conjugated MSNs demonstrated less toxicity to normal cells compared to cancer cells. Furthermore, the genotoxicity studies revealed the clastogenic and aneugenic effects of these nanoconjugates in CHO cells mostly at high concentrations. These interesting observations are behind the idea of developing tin-conjugated MSNs as prospective candidates for anticancer therapy.

Breast cancer screening in sub-Saharan Africa: a systematic review and ethical appraisal

Background

The aim of this systematic review was to evaluate the evidence and clinical outcomes of screening interventions and implementation trials in sub-Saharan Africa (SSA) and also appraise some ethical issues related to screening in the region through quantitative and qualitative narrative synthesis of the literature.

Methods

We searched Pubmed, OvidMEDLINE, Embase, and Web of Science to identify studies published on breast cancer screening interventions and outcomes in SSA. Descriptive statistics were used to summarize the frequency and proportions of extracted variables, and narrative syntheses was used to evaluate the clinical outcomes of the different screening modalities. The mixed methods appraisal tool was used to assess the quality of studies included in the review.

Results

Fifteen studies were included, which consisted of 72,572 women in ten countries in SSA. 63% (8/15) of the included publications evaluated Clinical Breast Examination (CBE), 47% (7/15) evaluated mammography and 7% (1/15) evaluated ultrasound screening. The cancer detection rate was < 1/1000 to 3.3/1000 and 3.3/100 to 56/1000 for CBE and mammography screening respectively. There was a lot of heterogeneity in CBE methods, target age for screening and no clear documentation of screening interval. Cost-effective analyses showed that CBE screening linked to comprehensive cancer care is most cost effective. There was limited discussion of the ethics of screening, including the possible harms of screening in the absence of linkage to care. The gap between conducting good screening program and the appropriate follow-up with diagnosis and treatment remains one of the major challenges of screening in SSA.

Discussion

There is insufficient real-world data to support the systematic implementation of national breast cancer screening in SSA. Further research is needed to answer important questions about screening, and national and international partnerships are needed to ensure that appropriate diagnostic and treatment modalities are available to patients who screen positive.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09299-5.

Doctor recommendations and parents' HPV vaccination intentions in Kenya: A randomized survey

The causal effect of a doctor’s recommendation for Human Papillomavirus (HPV) vaccination on parents’ decisions in low-resource settings is not well understood. This study investigates how doctors’ endorsement of the HPV vaccine communicated through a public health poster affects parents’ decisions to vaccinate their daughters in Kenya. In January and February 2021, 600 parents of daughters eligible for the HPV vaccine but not yet vaccinated were recruited and completed a randomized survey. Participants saw a poster from a national campaign about HPV vaccination and either nothing further (Control) or an additional poster containing an HPV vaccine recommendation from a female (FDR) or male doctor (MDR). Primary outcomes are intentions to vaccinate and perceived safety of the HPV vaccine. Both recommendation arms increased the likelihood that participants reported the highest levels of vaccine intentions compared to control (FDR: 33.7% p = 0.01; MDR: 30.5%, p = 0.05, compared to Control (22.4%)) and safety perceptions (FDR: 24.2%. p = 0.09; MDR: 28.0%, p = 0.01, compared to Control (17.1%)) but there was no statistically significant increase in the likelihood to report above moderate vaccine intentions (FDR: 72.6%, p = 0.76; MDR: 72.5%, p = 0.77, compared to Control (71.4%)) or safety perceptions (FDR: 68.9%, p = 0.91; MDR: 75.0%, p = 0.17, compared to Control (68.6%)). We find no differential treatment effect by the recommending doctor’s gender. In conclusion, our results suggest that visual communication of a doctor’s support for the HPV vaccine can strengthen above-moderate intentions and safety perceptions but may not be enough to persuade the vaccine hesitant to vaccinate.

Provider Barriers and Facilitators of Breast Cancer Guideline-Concordant Therapy Delivery in Botswana: A Consolidated Framework for Implementation Research Analysis

Introduction

Systemic treatment for breast cancer in sub‐Saharan Africa (SSA) is cost effective. However, there are limited real‐world data on the translation of breast cancer treatment guidelines into clinical practice in SSA. The study aimed to identify provider factors associated with adherence to breast cancer guideline‐concordant care at Princess Marina Hospital (PMH) in Botswana.

Materials and Methods

The Consolidated Framework for Implementation Research was used to conduct one‐on‐one semistructured interviews with breast cancer providers at PMH. Purposive sampling was used, and sample size was determined by thematic saturation. Transcribed interviews were double‐coded and analyzed in NVivo using an integrated analysis approach.

Results

Forty‐one providers across eight departments were interviewed. There were variations in breast cancer guidelines used. Facilitators included a strong tension for change and a government‐funded comprehensive cancer care plan. Common provider and health system barriers were lack of available resources, staff shortages and poor skills retention, lack of relative priority compared with HIV/AIDS, suboptimal interdepartmental communication, and lack of a clearly defined national cancer control policy. Community‐level barriers included accessibility and associated transportation costs. Participants recommended the formal implementation of future guidelines that involved key stakeholders in all phases of planning and implementation, strategic government buy‐in, expansion of multidisciplinary tumor boards, leveraging nongovernmental and academic partnerships, and setting up monitoring, evaluation, and feedback processes.

Discussion

The study identified complex, multilevel factors affecting breast cancer treatment delivery in Botswana. These results and recommendations will inform strategies to overcome specific barriers in order to promote standardized breast cancer care delivery and improve survival outcomes.

Implications for Practice

To address the increasing cancer burden in low‐ and middle‐income countries, resource‐stratified guidelines have been developed by multiple international organizations to promote high‐quality guideline‐concordant care. However, these guidelines still require adaptation in order to be successfully translated into clinical practice in the countries where they are intended to be used. This study highlights a systematic approach of evaluating important contextual factors associated with the successful adaptation and implementation of resource‐stratified guidelines in sub‐Saharan Africa. In Botswana, there is a critical need for local stakeholder input to inform country‐level and facility‐level resources, cancer care accessibility, and community‐level barriers and facilitators.

To address an increasing mortality burden, resource‐stratified guidelines have been developed to ensure that breast cancer care is matched to specific resources in low‐ and middle‐income countries. This article identifies facilitators and barriers to the use of breast cancer guidelines by oncology providers at Princess Marina Hospital in Botswana using the Consolidated Framework for Implementation Research (CFIR).

Impact of COVID-19 on Outcomes for Patients With Cervical Cancer in India

PURPOSE

The COVID-19 pandemic has placed unprecedented demands on the health system. This led to delays in the initiation and completion of cancer treatment. We assessed the long-term health consequences because of the delay in diagnosis and treatment for cervical cancer due to COVID-19 in India.

METHODS

We used a Markov-model–based analysis assessing the lifetime health outcomes of the cohort of women population at risk from cervical cancer in India. The decrease in survival for those with the treatment interruption was calculated based on the number of days the treatment was extended beyond the standard duration. Furthermore, to model the impact of late diagnosis and delayed treatment initiation, the patients were assumed to have upstaged during the delay period, as per natural progression of disease.

RESULTS

We estimate 2.52% (n = 795) to 3.80% (n = 2,160) lifetime increase in the deaths caused by cervical cancer with treatment restrictions ranging from 9 weeks to 6 months, respectively, as compared to no delay. On the contrary, 88-238 deaths because of COVID-19 disease are estimated to be saved during this restriction period among the patients with cervical cancer. Overall, the excess mortality because of cervical cancer led to 18,159-53,626 life-years being lost and an increase of 16,808-50,035 disability-adjusted life-years.

CONCLUSION

Delays in diagnosis and treatment are likely to lead to more cervical cancer deaths as compared to COVID-19 mortality averted among the patients with cervical cancer. Health systems must reorganize in terms of priority setting for provision of care, starting with prioritizing the treatment of patients with early-stage cervical cancer, increasing use of teleconsultation, and strengthening the role of primary care physicians in provision of cancer care.

Is it too expensive to fight cancer? Analysis of incremental costs and benefits of the Croatian National Plan Against Cancer

This cost-effectiveness study analyses the expected impacts of activities proposed by the Croatian National Plan Against Cancer (NPAC) on cancer incidence and survival rates, as related to their respective costs. We evaluated the impact of the NPAC on two main outcomes, namely, reduced incidence and the improved survival of cancer patients, expressed as life years gained (LYGs), which enabled the calculation of incremental cost-effectiveness ratios (ICERs) in the form of cost per LYG. In the analysis of costs, we considered both the direct costs of NPAC activities as well as the wider indirect societal costs of cancer, thus permitting the calculation of the ICER both from the narrower national health insurer's perspective (accounting only for the direct costs) and the wider societal perspective (accounting both for the direct and indirect costs). We estimated that on average, for all patients benefiting from the implementation of the NPAC in Croatia, an additional LYG would be yielded at the additional cost of €1.021 (societal perspective). The NPAC can, for some sites, even be considered a dominant intervention due to the negative cost/LYG ratio, meaning that it generates additional LYGs while at the same time, reducing total societal costs. Taking a narrower health insurer's perspective (i.e., accounting only for the direct costs), the NPAC produces an additional LYG at an additional cost of €1.408. Both cost per LYG estimates can be considered cost-effective investment options.

Brief Report: Modeling the Impact of Voluntary Medical Male Circumcision on Cervical Cancer in Uganda

BACKGROUND

In addition to providing millions of men with lifelong lower risk for HIV infection, voluntary medical male circumcision (VMMC) also provides female partners with health benefits including decreased risk for human papillomavirus (HPV) and resultant cervical cancer (CC).

SETTING

We modeled potential impacts of VMMC on CC incidence and mortality in Uganda as an additional benefit beyond HIV prevention.

METHODS

HPV and CC outcomes were modeled using the CC model from the Spectrum policy tool suite, calibrated for Uganda, to estimate HPV infection incidence and progression to CC, using a 50-year (2018-2067) time horizon. 2016 Demographic Health Survey data provided baseline VMMC coverage. The baseline (no VMMC scale-up beyond current coverage, minimal HPV vaccination coverage) was compared with multiple scenarios to assess the varying impact of VMMC according to different implementations of HPV vaccination and HPV screening programs.

RESULTS

Without further intervention, annual CC incidence was projected to rise from 16.9 to 31.2 per 100,000 women in 2067. VMMC scale-up alone decreased 2067 annual CC incidence to 25.3, averting 13,000 deaths between 2018 and 2067. With rapidly-achieved 90% HPV9 vaccination coverage for adolescent girls and young women, 2067 incidence dropped below 10 per 100,000 with or without a VMMC program. With 45% vaccine coverage, the addition of VMMC scaleup decreased incidence by 2.9 per 100,000 and averted 8000 additional deaths. Similarly, with HPV screen-and-treat without vaccination, the addition of VMMC scaleup decreased incidence by 5.1 per 100,000 and averted 10,000 additional deaths.

CONCLUSIONS

Planned VMMC scale-up to 90% coverage from current levels could prevent a substantial number of CC cases and deaths in the absence of rapid scale-up of HPV vaccination to 90% coverage.

Molecular mechanism and pharmacokinetics of flavonoids in the treatment of resistant EGF receptor-mutated non-small-cell lung cancer: A narrative review

Here, we review the molecular mechanism and pharmacokinetics of flavonoids in the treatment of resistant EGF receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC) and particularly the possible mechanism(s) of delicaflavone, a biflavonoid extracted from Selaginella doederleinii Hieron. EGFR TK inhibitors (EGFR-TKI) are ubiquitously used in the treatment of NSCLC bearing EGFR mutations. However, patients treated with EGFR-TKI inevitably and continuously develop resistance. In laboratory studies, flavonoids, as potential adjuvants for cancer chemotherapy, exhibited anti-cancer properties such as inhibition of chemoresistance by interference with ABC transporters-induced drug efflux, curbing of c-MET amplification, or reversal of T790M mutation-mediated resistance. The current review aims at summarizing the association between the anti-cancer potentials of flavonoids and their possible regulatory roles in certain types of mutation that could trigger EGFR-TKI resistance in NSCLC. Potential practical applications of these phytochemicals, as well as the relevant pharmacokinetics, are also discussed.

Why is appropriate healthcare inaccessible for many European breast cancer patients? - The EBCC 12 manifesto

In Europe, inappropriate reimbursement and funding rules and regulations act as disincentives to best breast cancer care or, at worst, hinder best care. This problem was the focus of the 12th European Breast Cancer Conference (EBCC) manifesto, discussed during the virtual conference. As patient involvement is indispensable in driving changes to clinical practice, Europa Donna the European patient advocacy group was closely involved in the 12th manifesto. Reimbursement policies have rarely evolved with advances in breast cancer care such as outpatient (ambulatory) care rather than inpatient admission, use of oral or subcutaneous anti-cancer drugs rather than day-hospital intravenous administration, oncoplastic surgery techniques to minimize mastectomy rates, breast reconstructive surgery, risk-reducing surgery for BRCA mutation carriers, or use of hypo-fractionated breast radiation therapy. Although each European country, region and centre will have to understand how their reimbursement policies may hinder best care and find their own solutions, the problems are similar throughout Europe and some solutions can be broadly applied. This manifesto is not calling for more funding or demanding changes that will result in more expensive care. Reimbursement, if better aligned with guidelines and optimal clinical practice, will deliver more cost-effective healthcare. This will release resources, support more equitable use of finite funding and resources, so allowing more European breast cancer patients to benefit from evidence-based treatment recommended by national and international guidelines.

Generalised cost-effectiveness analysis of 159 health interventions for the Ethiopian essential health service package

BACKGROUND

Cost effectiveness was a criterion used to revise Ethiopia's essential health service package (EHSP) in 2019. However, there are few cost-effectiveness studies from Ethiopia or directly transferable evidence from other low-income countries to inform a comprehensive revision of the Ethiopian EHSP. Therefore, this paper reports average cost-effectiveness ratios (ACERs) of 159 health interventions used in the revision of Ethiopia's EHSP.

METHODS

In this study, we estimate ACERs for 77 interventions on reproductive maternal neonatal and child health (RMNCH), infectious diseases and water sanitation and hygiene as well as for 82 interventions on non-communicable diseases. We used the standardised World Health Organization (WHO) CHOosing Interventions that are cost effective methodology (CHOICE) for generalised cost-effectiveness analysis. The health benefits of interventions were determined using a population state-transition model, which simulates the Ethiopian population, accounting for births, deaths and disease epidemiology. Healthy life years (HLYs) gained was employed as a measure of health benefits. We estimated the economic costs of interventions from the health system perspective, including programme overhead and training costs. We used the Spectrum generalised cost-effectiveness analysis tool for data analysis. We did not explicitly apply cost-effectiveness thresholds, but we used US$100 and $1000 as references to summarise and present the ACER results.

RESULTS

We found ACERs ranging from less than US$1 per HLY gained (for family planning) to about US$48,000 per HLY gained (for treatment of stage 4 colorectal cancer). In general, 75% of the interventions evaluated had ACERs of less than US$1000 per HLY gained. The vast majority (95%) of RMNCH and infectious disease interventions had an ACER of less than US$1000 per HLY while almost half (44%) of non-communicable disease interventions had an ACER greater than US$1000 per HLY.

CONCLUSION

The present study shows that several potential cost-effective interventions are available that could substantially reduce Ethiopia's disease burden if scaled up. The use of the World Health Organization's generalised cost-effectiveness analysis tool allowed us to rapidly calculate country-specific cost-effectiveness analysis values for 159 health interventions under consideration for Ethiopia's EHSP.

Pausing cancer screening during the severe acute respiratory syndrome coronavirus 2pandemic: Should we revisit the recommendations?

•The outbreak of severe acute respiratory syndrome coronavirus has become a global major concern. •Medical professionals were instructed to use their clinical judgement when scheduling elective activity. •Delays in cancer screening, should not go unnoticed and this ‘knee-jerk’ response should be revisited. •If the current situation last, we anticipate that thousands of cases will be diagnosed late or missed.

National Policies to Prevent and Manage Cervical Cancer in East African Countries: A Policy Mapping Analysis

Policy mapping is used to provide evidence on effective interventions and highlight the necessary refinements of health policies. The goal of this work is to carry out legal mapping to identify and assess health policies for the prevention and management of cervical cancer in East African countries. Cervical cancer, as a largely preventable disease, is the cause of most cancer deaths among women in East African countries. Legal documents were searched uniformly from government websites, national cancer institute sites, and international and national legal databases, then the data were analyzed using the Nvivo12 software package. The sample of 24 documents includes policies, plans, guidelines, acts, and strategies from 12 East African countries. The emerging themes were screening, prevention, diagnosis, treatment, challenges, and mitigation efforts. A few binding policies, a significant discrepancy to international standards in at least four countries, patchy screening registries, and a lack of prophylactic vaccination against human papillomavirus incorporation into national immunization schedules are the main findings. This paper underlies the role of law in health and the need for transparent legal and regulatory tools to achieve a further reduction in cervical cancer mortality in East African countries.

Differential mechanisms of autophagy in cancer stem cells: Emphasizing gastrointestinal cancers

Gastrointestinal (GI) cancers are one of the most common forms of malignancies and still are the most important cause of cancer-related mortality worldwide. Autophagy is a conserved catabolic pathway involving lysosomal degradation and recycling of whole cellular components, which is essential for cellular homeostasis. For instance, it acts as a pivotal intracellular quality control and repair mechanism but also implicated in cell reformation during cell differentiation and development. Indeed, GI cancer stem cells (CSCs) are thought to be responsible for tumour initiation, traditional therapies resistance, metastasis and tumour recurrence. Molecular mechanisms of autophagy in normal vs CSCs gain great interest worldwide. Here, we shed light on the role of autophagy in normal stem cells differentiation for embryonic progression and its role in maintaining the activity and self-renewal capacity of CSCs which offer novel viewpoints on promising cancer therapeutic strategies based on the differential roles of autophagy in CSCs.

Analysis of Mammography Screening Schedules under Varying Resource Constraints for Planning Breast Cancer Control Programs in Low- and Middle-Income Countries: A Mathematical Study

Background. Low-and-middle-income countries (LMICs) have higher mortality-to-incidence ratio for breast cancer compared to high-income countries (HICs) because of late-stage diagnosis. Mammography screening is recommended for early diagnosis, however, the infrastructure capacity in LMICs are far below that needed for adopting current screening guidelines. Current guidelines are extrapolations from HICs, as limited data had restricted model development specific to LMICs, and thus, economic analysis of screening schedules specific to infrastructure capacities are unavailable. Methods. We applied a new Markov process method for developing cancer progression models and a Markov decision process model to identify optimal screening schedules under a varying number of lifetime screenings per person, a proxy for infrastructure capacity. We modeled Peru, a middle-income country, as a case study and the United States, an HIC, for validation. Results. Implementing 2, 5, 10, and 15 lifetime screens would require about 55, 135, 280, and 405 mammography machines, respectively, and would save 31, 62, 95, and 112 life-years per 1000 women, respectively. Current guidelines recommend 15 lifetime screens, but Peru has only 55 mammography machines nationally. With this capacity, the best strategy is 2 lifetime screenings at age 50 and 56 years. As infrastructure is scaled up to accommodate 5 and 10 lifetime screens, screening between the ages of 44-61 and 41-64 years, respectively, would have the best impact. Our results for the United States are consistent with other models and current guidelines. Limitations. The scope of our model is limited to analysis of national-level guidelines. We did not model heterogeneity across the country. Conclusions. Country-specific optimal screening schedules under varying infrastructure capacities can systematically guide development of cancer control programs and planning of health investments.

Impact of HPV vaccination and cervical screening on cervical cancer elimination: a comparative modelling analysis in 78 low-income and lower-middle-income countries

BACKGROUND

The WHO Director-General has issued a call for action to eliminate cervical cancer as a public health problem. To help inform global efforts, we modelled potential human papillomavirus (HPV) vaccination and cervical screening scenarios in low-income and lower-middle-income countries (LMICs) to examine the feasibility and timing of elimination at different thresholds, and to estimate the number of cervical cancer cases averted on the path to elimination.

METHODS

The WHO Cervical Cancer Elimination Modelling Consortium (CCEMC), which consists of three independent transmission-dynamic models identified by WHO according to predefined criteria, projected reductions in cervical cancer incidence over time in 78 LMICs for three standardised base-case scenarios: girls-only vaccination; girls-only vaccination and once-lifetime screening; and girls-only vaccination and twice-lifetime screening. Girls were vaccinated at age 9 years (with a catch-up to age 14 years), assuming 90% coverage and 100% lifetime protection against HPV types 16, 18, 31, 33, 45, 52, and 58. Cervical screening involved HPV testing once or twice per lifetime at ages 35 years and 45 years, with uptake increasing from 45% (2023) to 90% (2045 onwards). The elimination thresholds examined were an average age-standardised cervical cancer incidence of four or fewer cases per 100 000 women-years and ten or fewer cases per 100 000 women-years, and an 85% or greater reduction in incidence. Sensitivity analyses were done, varying vaccination and screening strategies and assumptions. We summarised results using the median (range) of model predictions.

FINDINGS

Girls-only HPV vaccination was predicted to reduce the median age-standardised cervical cancer incidence in LMICs from 19·8 (range 19·4-19·8) to 2·1 (2·0-2·6) cases per 100 000 women-years over the next century (89·4% [86·2-90·1] reduction), and to avert 61·0 million (60·5-63·0) cases during this period. Adding twice-lifetime screening reduced the incidence to 0·7 (0·6-1·6) cases per 100 000 women-years (96·7% [91·3-96·7] reduction) and averted an extra 12·1 million (9·5-13·7) cases. Girls-only vaccination was predicted to result in elimination in 60% (58-65) of LMICs based on the threshold of four or fewer cases per 100 000 women-years, in 99% (89-100) of LMICs based on the threshold of ten or fewer cases per 100 000 women-years, and in 87% (37-99) of LMICs based on the 85% or greater reduction threshold. When adding twice-lifetime screening, 100% (71-100) of LMICs reached elimination for all three thresholds. In regions in which all countries can achieve cervical cancer elimination with girls-only vaccination, elimination could occur between 2059 and 2102, depending on the threshold and region. Introducing twice-lifetime screening accelerated elimination by 11-31 years. Long-term vaccine protection was required for elimination.

INTERPRETATION

Predictions were consistent across our three models and suggest that high HPV vaccination coverage of girls can lead to cervical cancer elimination in most LMICs by the end of the century. Screening with high uptake will expedite reductions and will be necessary to eliminate cervical cancer in countries with the highest burden.

FUNDING

WHO, UNDP, UN Population Fund, UNICEF-WHO-World Bank Special Program of Research, Development and Research Training in Human Reproduction, Canadian Institute of Health Research, Fonds de recherche du Québec-Santé, Compute Canada, National Health and Medical Research Council Australia Centre for Research Excellence in Cervical Cancer Control.