Preventing cancer with vaccines: progress in the global control of cancer

Key decision-making factors for human papillomavirus (HPV) vaccine program introduction in low-and-middle-income-countries: Global and national stakeholder perspectives

Low-and-middle-income countries (LMICs) experience a high burden of cervical cancer. The human papillomavirus (HPV) vaccine prevents high-risk strains of HPV that cause cervical cancer; however, the integration of HPV vaccines into national immunization programs within many LMICs has been suboptimal. Our study evaluated key factors that drive the decision-making process for the implementation of HPV vaccine programs in LMICs. Stakeholder analysis and semi-structured in-depth interviews were conducted with national and global stakeholders. Interview data were analyzed through qualitative descriptive methods. Findings from our study revealed the decision-making process for HPV vaccines requires the involvement of multiple institutions and stakeholders from national and global levels, with decision-making being a country-specific process. Partner considerations, locally driven processes, availability of data, and infrastructure and resource considerations were found to be critical factors in the decision-making process. Future programs should evaluate the best approaches for investing in initiatives to enhance coordination, ensure vaccine introduction is locally driven, increase the availability of data needed for decision-making, and equip countries with the necessary resources to guide country decision-making in the face of increasingly complex decision-making environments.

Influenza Vaccination and Risk of Lung Cancer in Patients with Chronic Kidney Disease: A Nationwide, Population-Based Cohort Study

Chronic kidney disease (CKD) is significantly associated with lung cancer incidence. The aim of this study was to elucidate whether influenza vaccination reduces the incidence of lung cancer in patients with CKD. This cohort study enrolled patients with a record of CKD diagnosis from 2000 to 2012 in Taiwan’s National Health Insurance Research Database. Included patients were divided into vaccinated and unvaccinated groups. In total 12,985 patients with CKD were enrolled. Among these patients, 5495 were vaccinated and 7490 were unvaccinated. The risk of lung cancer was significantly lower in the influenza vaccination group after adjusting for age, sex, dialysis status, lung diseases, comorbidities, level of urbanization, and monthly income (adjusted hazard ratio (HR): 0.50, 95% confidence interval (CI; 0.38−0.65), p < 0.05). Lower risk of lung cancer was observed in both sexes, all age groups, dialysis status and co-existed lung diseases. The association between the risk of lung cancer and vaccination appeared to be dose-dependent (adjusted HRs: 0.91 (0.66−1.25), 0.49 (0.34−0.71), and 0.25 (0.17−0.38) for patients who received 1, 2 or 3, and ≥4 vaccinations during the follow-up period, respectively). In conclusion, Influenza vaccination decreased the risk of lung cancer in patients diagnosed with CKD. This potentially protective effect against lung cancer appeared to be dose dependent.

Identification of key classification features of early cervical squamous cell carcinoma

Despite the tremendous progress in molecular analysis of pan-cancer, little is known regarding molecular classification of cervical squamous cell carcinoma. In this study, we adopted a multi-omics approach to identify potential key classification features of cervical squamous cell carcinoma. Specifically, we analyzed mRNA, and microRNA (miRNA) expression data, as well as DNA methylation and copy number variation in cervical squamous cell carcinoma cases, using datasets obtained from The Cancer Genome Atlas (TCGA). Moreover, we identified molecules in each dimension, as well as integrated and clustered filtered classification features, and used them to distinguish different subtypes. The resulting key classification features were used to establish a classification model for cervical squamous cell carcinoma. Our results revealed two cervical squamous cell carcinoma subtypes, with significant differences across clinical survival levels, as well as 8 key classification features of cervical squamous cell carcinomas. These findings are expected to provide important references for early classification of cervical squamous cell carcinoma and identification of classification markers.

HPV-Associated Tumor Eradication by Vaccination with Synthetic Short Peptides and Particle-Forming Liposomes

Human papilloma virus (HPV)-16 is associated with cervical cancers and induces expression of the E6 and E7 oncogenes. Using a murine cell line that expresses these, the genes are sequenced, and six predicted major histocompatibility complex (MHC) class I (MHC-I) epitopes are identified. A liposomal vaccine adjuvant based on cobalt-porphyrin-phospholipid (CoPoP) is admixed with synthetic 9-mer epitopes appended with three histidine residues, resulting in rapid formation of peptide-liposome particles. Immunization with multivalent peptides leads to protection from tumor challenge. Of the peptides screened, only the previously identified E749-57 epitope is functional. The peptide-liposome particles that form upon mixing E7HHH49-57 with CoPoP liposomes are stable in serum and are avidly taken up by immune cells in vitro. Immunization results in robust protection from tumor challenge and re-challenge. A 100 ng peptide dose protects mice in a therapeutic tumor challenge when admixed with CoPoP liposomes, whereas 200-fold higher peptide doses are ineffective with the polyinosinic-polycytidylic (poly(I:C)) adjuvant. CoPoP induces a strong infiltrating CD8+ T-cell response within the tumor microenvironment with an improved functional profile. Vaccine monotherapy using nanogram dosing of the E7HHH49-57 peptide admixed with CoPoP reverses the growth of large established tumors, eradicating subcutaneous tumors upwards of 100 mm3 . Immunization also eradicates lung tumors in a metastasis model.

Effect of annual influenza vaccination on reducing lung cancer in patients with chronic obstructive pulmonary disease from a population-based cohort study

Chronic obstructive pulmonary disease (COPD) patients are at a higher risk of development of lung cancer. Frequent exacerbations of COPD trigger the disease course to chronic inflammation which likely plays a role in the pathogenesis of lung cancer. Previous studies showed influenza virus infection is one of important causes for exacerbations of COPD. Therefore, the aim of this study was to know whether influenza vaccination could reduce the incidence of lung cancer in patients with COPD.This cohort study enrolled patients (≥55 years old) with a recorded diagnosis of COPD between January 1, 2000 and December 31, 2012 by using the Taiwan Health Insurance Database. A propensity score was calculated to reduce vaccine therapy selection bias. Cox proportional hazard regressions were used to investigate the association between the influenza vaccination and lung cancer incidence after adjusting for known confounding factors. Besides, we categorized the patients into 4 groups according to vaccination status (unvaccinated, total number of vaccinations: 1, 2-3, ≥4) to evaluate the dose-dependent effect on reducing lung cancer occurrence of lung cancer in COPD patients.Our study comprised of 28,752 eligible individuals from the COPD cohort database. Among them, 51% (14,630) received influenza vaccination; the rest (49%) of the COPD patients did not receive influenza vaccination. We observed that COPD patients receiving influenza vaccination had a lower risk of lung cancer (adjusted HR = 0.40, 95% CI (0.35-0.45), P < .001). We also founded comparable protective effect in both sexes and all age groups (55-64, 65-74, ≥75) regardless of influenza seasonality. Furthermore, dose-dependent protective effect could be seen after stratifying patients according to the total number vaccinations, the adjusted HRs for lung cancer risk were 0.48 (0.40-0.54) and 0.24 (0.20-0.29) for patients who received 2 to 3 and ≥4 vaccinations during the follow-up period.This population-based cohort study demonstrated that annual influenza vaccination administration could reduce incidence of lung cancer in COPD patients.

Breast cancer and cytomegalovirus

PURPOSE

To determine whether cytomegalovirus is causally associated with breast cancer and whether cytomegalovirus should be categorised as an oncogenic virus.

METHODS

We undertook a review of published epidemiological and laboratory studies, using established causal criteria: Bradford Hill criteria to determine whether cytomegalovirus is associated with breast cancer; and Evans/Mueller criteria to determine whether cytomegalovirus should be categorised as an oncogenic virus.

RESULTS

Although there are inconsistencies in the findings of published epidemiological and laboratory studies, these may be explained by factors such as: differences in timing of blood samples, differences in selection of cases and controls, or high cytomegalovirus seroprevalence among participants in the epidemiological studies; and, in the laboratory studies, differences in sample preparations, age of sample, whether or not paired breast cancer and normal breast tissue samples were used, differences in the tests, primers and/or antibodies used, differences in histological types of breast cancer studied, and/or features of the virus.

CONCLUSIONS

Overall, the results of published studies of cytomegalovirus and breast cancer suggest cytomegalovirus is a causal factor for at least some types of breast cancer. If the evidence for a link between cytomegalovirus and breast cancer continues to strengthen, further research could lead to: targeted screening; therapy using antiviral drugs; and, perhaps, primary prevention of a significant proportion of breast cancer. Vaccination against viruses has already been shown to be effective in preventing cervix and liver cancer; cytomegalovirus vaccines are already under development.

Prevention of Cervical Cancer in Sub-Saharan Africa: The Advantages and Challenges of HPV Vaccination

Cervical cancer is a critical public health issue in sub-Saharan Africa (SSA), where it is the second leading cause of cancer among women and the leading cause of female cancer deaths. Incidence and mortality rates are substantially higher than in high-income countries with population-based screening programs, yet implementing screening programs in SSA has so far proven to be challenging due to financial, logistical, and sociocultural factors. Human Papillomavirus (HPV) vaccination is an effective approach for primary prevention of cervical cancer and presents an opportunity to reduce the burden from cervical cancer in SSA. With a number of SSA countries now eligible for Global Alliance for Vaccines and Immunization (GAVI) support for vaccine introduction, it is timely to consider the factors that impede and facilitate implementation of vaccine programs in SSA. This article describes epidemiological features of cervical cancer in SSA and the current status of HPV vaccine implementation in SSA countries. Rwanda’s experience of achieving high vaccination coverage in their national HPV immunization program is used as a case study to explore effective approaches to the design and implementation of HPV vaccination programs in SSA. Key factors in Rwanda’s successful implementation included government ownership and support for the program, school-based delivery, social mobilization, and strategies for reaching out-of-school girls. These findings might usefully be applied to other SSA countries planning for HPV vaccination.

Relating business model innovations and innovation cascades: the case of biotechnology

This article conceptualizes innovation as a process, where the scientific and industrial application of technological knowledge nurtures new routines and institutions, in order to relate changing business model innovations to innovation cascades. Innovation in science-based, high-tech sectors is changing its tempo, from the evolutionary pace of incremental novelties punctuated by occasional radical novelties, to innovation cascades. These cascades involve a long series of interlinked radical innovations, which can be traced through various scientific and technological indicators like patents and publications. Innovation cascades are relevant to industry, because they make the future less predictable. They are particularly interesting because these changes also enable the testing an abundance of new business models. Innovation cascades have a major impact on the number and sustainability of business models and on strategy. Business model innovations are visible not only in the existing organizations that undergo change, but also new organizational models appear. The case of biotechnology after the 1980s is used to illustrate our conceptualization.

Human Papillomavirus Vaccination Among Adults and Children in 5 US States

CONTEXT

The Centers for Disease Control and Prevention Advisory Committee for Immunization Practices has recommended human papillomavirus (HPV) vaccines for use in children and young adults for preventing HPV-related diseases, but HPV vaccine coverage is low in the United States.

OBJECTIVE

To assess HPV vaccination among US adults and children and to identify characteristics associated with HPV vaccination.

METHODS

We used the 2010 Behavioral Risk Factors Surveillance System data to examine HPV vaccine initiation and completion among adults aged 18 to 26 years and children aged 9 to 17 years in 5 US states. We performed a multivariate logistic regression to evaluate factors associated with HPV vaccination.

RESULTS

We assessed the HPV vaccination status of 706 women and 560 men and 2201 girls and 2292 boys. In 2010, a total of 258 (41.6%) women and 21 (4.3%) men had initiated HPV vaccination. Of those vaccinated women, 182 (75%) completed the 3-dose vaccine series. Rural residence (adjusted odds ratio [aOR] = 0.37) and not having a Papanicolaou test (aOR = 0.44) were negatively associated with HPV vaccine initiation among women. Women who were aged 18 to 20 years (aOR = 2.93) were more likely to complete HPV vaccination. A total of 612 (24.6%) girls and 86 (5.2%) boys received 1 or more doses of HPV vaccines; 308 (50.3%) vaccinated girls and 14 (10.8%) vaccinated boys completed the vaccine series. Younger age (9-12 years: aOR = 0.09) and not receiving a seasonal influenza vaccine (aOR = 0.44) were negatively related to HPV vaccine initiation in girls. Girls were less likely to initiate and complete HPV vaccination if their parents did not have a routine checkup within 1 year.

CONCLUSION

HPV vaccination in the United States remains below the Healthy People 2020 objective (80%). To increase HPV vaccination, strategies still need to focus on improving access to HPV vaccines and utilization of health services.

Efficient Eradication of Established Tumors in Mice with Cationic Liposome-Based Synthetic Long-Peptide Vaccines

Therapeutic vaccination with synthetic long peptides (SLP) can be clinically effective against HPV-induced premalignant lesions; however, their efficiency in established malignant lesions leaves room for improvement. Here, we report the high therapeutic potency of cationic liposomes loaded with well-defined tumor-specific SLPs and a TLR3 ligand as adjuvant. The cationic particles, with an average size of 160 nm, could strongly activate functional, antigen-specific CD8⁺ and CD4⁺ T cells and induced in vivo cytotoxicity against target cells after intradermal vaccination. At a low dose (1 nmol) of SLP, our liposomal formulations significantly controlled tumor outgrowth in two independent models (melanoma and HPV-induced tumors) and even cured 75%-100% of mice of their large established tumors. Cured mice were fully protected from a second challenge with an otherwise lethal dose of tumor cells, indicating the potential of liposomal SLP in the formulation of powerful vaccines for cancer immunotherapy. Cancer Immunol Res; 5(3); 222-33. ©2017 AACR.

HPV vaccine completion and dose adherence among commercially insured females aged 9 through 26 years in the US

BACKGROUND

Although HPV vaccination has been recommended for use in girls and young women since 2007, HPV vaccine uptake is low in the US.

METHODS

We conducted a retrospective cohort study using the 2008-2011 MarketScan data to examine HPV vaccine completion and dose adherence among commercially insured females aged 9-26 years. We performed multivariable logistic regression models to examine factors related to HPV vaccine completion and HPV vaccine dose adherence.

RESULTS

Among 378,484 females aged 9-26 years who initiated HPV vaccination, only 29.4% completed HPV vaccination. Compared with females receiving vaccines from primary care providers, those receiving vaccines from OB/GYN providers were more likely to complete the vaccine series. Age at HPV vaccine initiation, health insurance plan, seasonal pattern, and flu vaccination were also significantly associated with vaccine completion. Among 111,286 females who completed HPV vaccination, 62.4% received all doses within 30 days of the recommended schedules. Similar factors relating to HPV vaccine completion were consistently associated with HPV vaccine dose adherence. However, younger age (<22 years) and receipt of flu vaccine were negatively related to HPV vaccine dose adherence.

CONCLUSIONS

Intervention programs to improve HPV vaccine reminding system and reduce logistic barriers for both physicians and patients are warranted.

Transforming Cancer Prevention through Precision Medicine and Immune-oncology

We have entered a transformative period in cancer prevention (including early detection). Remarkable progress in precision medicine and immune-oncology, driven by extraordinary recent advances in genome-wide sequencing, big-data analytics, blood-based technologies, and deep understanding of the tumor immune microenvironment (TME), has provided unprecedented possibilities to study the biology of premalignancy. The pace of research and discovery in precision medicine and immunoprevention has been astonishing and includes the following clinical firsts reported in 2015: driver mutations detected in circulating cell-free DNA in patients with premalignant lesions (lung); clonal hematopoiesis shown to be a premalignant state; molecular selection in chemoprevention randomized controlled trial (RCT; oral); striking efficacy in RCT of combination chemoprevention targeting signaling pathway alterations mechanistically linked to germline mutation (duodenum); molecular markers for early detection validated for lung cancer and showing promise for pancreatic, liver, and ovarian cancer. Identification of HPV as the essential cause of a major global cancer burden, including HPV16 as the single driver of an epidemic of oropharyngeal cancer in men, provides unique opportunities for the dissemination and implementation of public health interventions. Important to immunoprevention beyond viral vaccines, genetic drivers of premalignant progression were associated with increasing immunosuppressive TME; and Kras vaccine efficacy in pancreas genetically engineered mouse (GEM) model required an inhibitory adjuvant (Treg depletion). In addition to developing new (e.g., epigenetic) TME regulators, recent mechanistic studies of repurposed drugs (aspirin, metformin, and tamoxifen) have identified potent immune activity. Just as precision medicine and immune-oncology are revolutionizing cancer therapy, these approaches are transforming cancer prevention. Here, we set out a brief agenda for the immediate future of cancer prevention research (including a "Pre-Cancer Genome Atlas" or "PCGA"), which will involve the inter-related fields of precision medicine and immunoprevention - pivotal elements of a broader domain of personalized public health.

Bevacizumab in Advanced Cervical Cancer: Issues and Challenges for Low- and Middle-Income Countries

Bevacizumab became the first molecular antibody to show survival benefit in advanced cervical cancer. In the GOG-0240 (Paclitaxel and Cisplatin or Topotecan With or Without Bevacizumab in Treating Patients With Stage IVB, Recurrent, or Persistent Cervical Cancer) trial, it improved overall survival by a significant 3.7 months over platinum doublet chemotherapy alone. However, this discovery is not likely to improve the status of global cervical cancer because more than 85% of patients with cervical cancer live in low- and middle-income countries and cannot afford bevacizumab. This commentary looks at the options by which this drug can be made more affordable and cost-effective for patients in low- and middle-income countries. We also discuss other important questions related to its affordability and cost issues such as the optimal number of cycles and personalizing the treatment. Finally, we emphasize that although the unaffordability of bevacizumab in cervical cancer seems to be a very important issue, the best cost-effective strategy against cervical cancer is prevention with screening and vaccination.

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.

Early-life exposures to infectious agents and later cancer development

There is a growing understanding that several infectious agents are acquired in early life and this is the reason why available vaccines target the new born, infants, and adolescents. Infectious agents are associated with cancer development and it is estimated that about 20% of the world's cancer burden is attributed to infectious agents. There is a growing evidence that certain infectious agents acquired in early life can give rise to cancer development, but estimates of the cancer burden from this early‐life acquisition is unknown. In this article, we have selected five cancers (cervical, liver, Burkitt's lymphoma‐leukemia, nasopharyngeal carcinoma, and adult T‐cell leukemia‐lymphoma) and examine their links to infectious agents (HPV, HBV, HCV, EBV, and HTLV‐1) acquired in early life. For these agents, the acquisition in early life is from mother‐to‐child transmission, perinatal contact (with genital tract secretions, amniotic fluids, blood, and breast milk), saliva, sexual intercourse, and blood transfusion. We also discuss prevention strategies, address future directions, and propose mechanisms of action after a long latency period from the time of acquisition of the infectious agent in early life to cancer development.

Vaccination against human papilloma virus infection in male adolescents: knowledge, attitudes, and acceptability among parents in Italy

OBJECTIVES

To elicit information about parents' knowledge, attitudes, and acceptability toward HPV infection and vaccination of male adolescents in Italy; to identify subgroups of this population who exhibit poor knowledge about prevention of HPV infection and reveal negative attitudes toward HPV vaccination in relation to their male sons.

STUDY DESIGN

Data were collected via self-administered anonymous questionnaire from 1021 parents of males aged 10 to 14 y who were recruited from a random sample of public secondary schools in the South of Italy.

RESULTS

Three-quarters (72.6%) reported that the vaccine is a preventive measure for HPV infection and 55.8% that condom use reduces the risk of HPV infection. A high education level, abundant sources of information about HPV infection received from physicians, and knowledge about HPV infection were factors significantly associated with high level of knowledge about preventive measures for HPV infection. 71% revealed their intentions to vaccinate their sons, and this intention was significantly associated with perceived benefits both for HPV vaccination for girls and for childhood recommended vaccinations as well as a need for additional information about HPV vaccination. 53.7% of the eligible parents reported that their daughters had been vaccinated against HPV.

CONCLUSION

Results of the study suggest that the risk of acquiring HPV infection and HPV-related diseases is sorely underestimated. Knowledge on the benefits of adolescents' HPV vaccination in cancer prevention in both sexes should be improved to maximize uptake of HPV vaccination.

Vaccines, new opportunities for a new society

Vaccination is the most effective medical intervention ever introduced and, together with clean water and sanitation, it has eliminated a large part of the infectious diseases that once killed millions of people. A recent study concluded that since 1924 in the United States alone, vaccines have prevented 40 million cases of diphtheria, 35 million cases of measles, and a total of 103 million cases of childhood diseases. A report from the World Health Organization states that today vaccines prevent 2.5 million deaths per year: Every minute five lives are saved by vaccines worldwide. Overall, vaccines have done and continue to do an excellent job in eliminating or reducing the impact of childhood diseases. Furthermore, thanks to new technologies, vaccines now have the potential to make an enormous contribution to the health of modern society by preventing and treating not only communicable diseases in all ages, but also noncommunicable diseases such as cancer and neurodegenerative disorders. The achievement of these results requires the development of novel technologies and health economic models able to capture not only the mere cost-benefit of vaccination, but also the value of health per se.

Perceptions of and barriers to vaccinating daughters against human papillomavirus (HPV) among mothers in Hong Kong

Background

Significant others are noted to be remarkable influences in modelling children’s and young people’s health perceptions and their adoption of health behaviour. The vaccinations which a child receives are shown to be significantly influenced by his or her parents. However, there is a paucity of Chinese-based studies. When discussing the Human Papillomavirus (HPV) vaccine, very few studies examine the perceptions of Chinese parents regarding the vaccine as a preventive health measure, and even fewer examine how these perceptions of the vaccine and sexual values influence their motivations in encouraging their children to be vaccinated. In view of the literature gap, this article investigates the perceptions of Hong Kong mothers in regard to vaccinating their daughters against HPV in Hong Kong.

Methods

A qualitative research approach with individual semi-structured interviews was conducted with 35 mothers aged 30 to 60 years old with daughter(s) between 9 and 17 years old.

Results

Six connected themes emerged. The participants commonly perceived the HPV vaccination as being unnecessary for their daughters in view of their young age. They worried that it would encourage their daughters to engage in premarital sex, and perceived the vaccination to be potentially harmful to health. Also, their low perceived risk of HPV in addition to the lack of reassurance from their health care providers failed to convince the participants that the vaccination was important for their daughters’ health. Finally, the participants found the vaccine to be expensive and perceived it to have little protection value in comparison to other optional vaccines.

Conclusion

The sampled mothers did not have a positive perception of the HPV vaccine. The cultural association between receiving the vaccination and premarital sex was prevalent. Bounded by their cultural values, the participants also had many misconceptions regarding the vaccine and the transmission of HPV, which discouraged them from having their daughters vaccinated. Furthermore, a lack of support from health care providers and the government health authorities concerning HPV vaccination failed to provide confidence and reassurance to mothers, and conveyed a meaning to these mothers that HPV vaccine is relatively unimportant.

Upscaling human papillomavirus vaccination in high-income countries: impact assessment based on transmission model

BACKGROUND

The decrease in human papillomavirus (HPV) vaccine prices may allow upscale already started vaccination programmes but the advantages of different options are unclear.

METHODS

Using a mathematical model of HPV16 and 18 transmission and data on vaccination coverage from Italy, we compared 3 options to upscale an already started programme targeting 11-year old girls (coverage 65%): a) coverage improvement (from 65% to 90%); b) addition of 11-year-old boys (coverage 65%); or c) 1-year catch-up of older girls (coverage 50%).

RESULTS

The reduction of cervical HPV16/18 infection as compared to no vaccination (i.e. effectiveness against HPV16/18) increased from 76% to 98% with coverage improvement in girls and to 90% with the addition of boys. With higher coverage in girls, HPV16/18 infection cumulative probability by age 35 decreased from 25% to 8% with a 38% increase in vaccine number. The addition of boys decreased the cumulative probability to 18% with a 100% increase in the number of vaccinees. For any coverage in girls, the number of vaccinees to prevent 1 woman from being infected by HPV16/18 by age 35 was 1.5, whereas it was 2.7 for the addition of boys. Catch-up of older girls only moved forward the vaccination effectiveness by 2-5 years.

CONCLUSIONS

Increasing vaccination coverage among girls is the most effective option for decreasing HPV16/18. If not achievable, vaccinating boys is justifiable if vaccine cost has at least halved, because this option would almost double the number of vaccinees.

The four steps in the prevention of human papillomavirus-associated neoplasia: considerations for preventive measures, screening, disease impact, and potential overtreatments in HPV-related pathology

There is no cure currently available for HPV infections, although ablative and excisional treatments of some dysplasias often result in a clinical and virological cure. Effective control measures of HPV-associated cancers rely on the prevention at four different levels. Apart from sexual abstinence, primary prevention is realized through vaccines targeting the most frequent HPV types: negative attitudes towards HPV vaccination and high costs are the main obstacles. The aim of secondary prevention is to detect precancerous changes before they develop into invasive cancer, while tertiary prevention involves actual treatment of high-grade lesions: in many countries routine screening with cytology is being challenged with HPV DNA testing. Quaternary prevention comprehends those actions adopted to mitigate or avoid unnecessary or excessive medical interventions, and may well be addressed in avoiding treatments for low-grade intraepithelial neoplasia. Though some gynecologists commonly recommend treatment for low-grade disease and women tend to prefer active management if not properly informed, harms arising from unnecessary treatments, increased costs, work overload for second-level health services, and induced psychosocial distress are causing on-going problems. Prevention efforts of genital HPV-associated cancers should concentrate in: (1) enhancing primary prevention through vaccination of all eligible subjects, (2) achieving high levels of adherence to routine screening programs, (3) treating precancerous lesions, and (4) monitoring current guidelines recommendations to avoid overtreatments. Novel research projects should be designed to study the delicate mechanisms of immune response to HPV.

Barriers to receiving human papillomavirus vaccination among female students in a university in Hong Kong

This paper investigates, using a qualitative approach, barriers to receiving Human Papillomavirus (HPV) vaccine among female undergraduate students in a Hong Kong university. By conducting individual semi-structured interviews with 35 young women aged 19 to 23, seven intertwining perceptual, social and cultural, healthcare provider and financial barriers were identified. These barriers included the perception as being low-risk due to an absence of sexual contact, lack of confidence in the safety of the vaccine, suspicion of parents concerning the intention to get vaccinated, lack of positive discussion among peers, insufficient information from primary-care doctors, difficulty in choosing a suitable HPV vaccine and cost of the vaccine. Future HPV-vaccination promotion therefore not only needs to enhance risk perception and needs awareness of young women, but also educate parents and correct their misconceptions. As primary care doctors are the first line of contact with patients, providing more support to enhance their knowledge of the HPV vaccine and to encourage their enthusiasm in providing responsive disease-prevention education can motivate young women to get vaccinated.

Differences in patterns of high-risk human papillomavirus infection between urban and rural low-resource settings: cross-sectional findings from Mali

BACKGROUND

The burden of cervical cancer is disproportionately high in low-resource settings. With limited implementation of human papillomavirus (HPV) vaccines on the horizon in the developing world, reliable data on the epidemiology of high-risk HPV (HR-HPV) infection in distinct geographic populations is essential to planners of vaccination programs. The purpose of this study was to determine whether urban patterns of HR-HPV occurrence can be generalized to rural areas of the same developing country, using data from Mali, West Africa, as an example.

METHODS

Urban and rural women in Mali participated in a structured interview and clinician exam, with collection of cervical samples for HPV DNA testing, to determine HR-HPV prevalence and correlates of infection. Correlates were assessed using bivariate analysis and logistic regression.

RESULTS

A total of 414 women (n=202 urban women; n=212 rural women) were recruited across both settings. The prevalence of HR-HPV infection in rural women was nearly twice that observed in urban women (23% v. 12%). Earlier age of sexual debut and fewer pregnancies were associated with HR-HPV infection among urban women, but not rural women. Twenty-six percent of urban women who had sexual intercourse by age 14 had an HR-HPV infection, compared to only 9% of those who had later sexual debut (p<0.01). Overall, age, income, and polygamy did not appear to have a relationship with HR-HPV infection.

CONCLUSIONS

Compared to urban women, rural women were significantly more likely to be infected with high-risk HPV. The patterns and risk factors of HR-HPV infection may be different between geographic areas, even within the same developing country. The high prevalence in both groups suggests that nearly all rural women and most urban women in Mali will be infected with HR-HPV during their lifetime, so the effects of risk factors may not be statistically apparent. To control HPV and cervical cancer in West Africa and the rest of the developing world, planners should prioritize vaccination in high-burden areas.

Potential impact of a nine-valent vaccine in human papillomavirus related cervical disease

Background

Information on human papillomavirus (HPV) type distribution is necessary to evaluate the potential impact of current and future HPV vaccines. We estimated the relative contribution (RC) to invasive cervical cancer (ICC) and precancerous cervical lesions of the nine HPV types (HPV 6/11/16/18/31/33/45/52/58) included in an HPV vaccine currently under development.

Methods

Estimations on ICC were based on an international study of 8,977 HPV positive cases and estimations on precancerous cervical lesions were extracted from a published meta-analysis including 115,789 HPV positive women. Globocan 2008 and 2010 World Population Prospects were used to estimate current and future projections of new ICC cases.

Results

RC of the 9 HPV types in ICC was 89.4%, with 18.5% of cases positive for HPV 31/33/45/52/58. Regional variations were observed. RCs varied by histology, ranging between 89.1% in squamous cell carcinomas (SCC) and 95.5% in adenocarcinomas (ADC). HPV 16/18/45 were detected in 94.2% of ADC. RC of the 9 types altogether decreased with age (trend test p < 0.0001), driven by the decrease in older ages of HPV 16/18/45. In contrast, the RC of HPV 31/33/52/58 increased with age. Due to population growth alone, projected estimates of ICC cases attributable to the 9 types are expected to rise from 493,770 new cases in 2012 to 560,887 new cases in 2025.

The RCs of individual high risk HPV types varied by cytological and histological grades of HPV-positive precancerous cervical lesions, and there was an under representation of HPV 18 and 45 compared to ICC.

Conclusions

The addition of HPV 31/33/45/52/58 to HPV types included in current vaccines could prevent almost 90% of ICC cases worldwide. If the nine-valent vaccine achieves the same degree of efficacy than previous vaccines, world incidence rates could be substantially reduced.

Notes from the field: "green" chemoprevention as frugal medicine

Prevention trials of whole foods or simple extracts offer prospects for reducing an expanding global burden of cancer effectively, and in contrast to promising isolated phytochemicals or pharmaceuticals, frugally. We use the term "green" chemoprevention to differentiate a food-centered approach that is sustainable in underserved populations. It can be applied to personalized medicine just as well as a pharmaceutical approach, but only green chemoprevention can be applied in both rich and poor settings. This MiniReview discusses some of the challenges of conducting food-based trials in developing countries, with particular emphasis on moving the limited number of promising phase II trials forward as placebo-controlled randomized trials, the gold standard for prevention studies. How does one define a placebo for a food? What is the regulatory context of such a food-based product? How can such products be produced and standardized to the benefit of a larger, individual trial, and importantly, the research community at large? What are the challenges and opportunities of conducting such trials in the international setting? Finally, how does one make the science practical?

Cervical cancer prevention in low- and middle-income countries: feasible, affordable, essential

The annual worldwide burden of the preventable disease cervical cancer is more than 530,000 new cases and 275,000 deaths, with the majority occurring in low- and middle-income countries (LMIC), where cervical cancer screening and early treatment are uncommon. Widely used in high-income countries, Pap smear (cytology based) screening is expensive and challenging for implementation in LMICs, where lower-cost, effective alternatives such as visual inspection with acetic acid (VIA) and rapid human papillomavirus (HPV)-based screening tests offer promise for scaling up prevention services. Integrating HPV screening with VIA in "screen-and-treat-or-refer" programs offers the dual benefits of HPV screening to maximize detection and using VIA to triage for advanced lesions/cancer, as well as a pelvic exam to address other gynecologic issues. A major issue in LMICs is coinfection with human immunodeficiency virus (HIV) and HPV, which further increases the risk for cervical cancer and marks a population with perhaps the greatest need of cervical cancer prevention. Public-private partnerships to enhance the availability of cervical cancer prevention services within HIV/AIDS care delivery platforms through initiatives such as Pink Ribbon Red Ribbon present an historic opportunity to expand cervical cancer screening in LMICs.

Cervical cancer prevention in low- and middle-income countries: feasible, affordable, essential

The annual worldwide burden of the preventable disease cervical cancer is more than 530,000 new cases and 275,000 deaths, with the majority occurring in low- and middle-income countries (LMIC), where cervical cancer screening and early treatment are uncommon. Widely used in high-income countries, Pap smear (cytology based) screening is expensive and challenging for implementation in LMICs, where lower-cost, effective alternatives such as visual inspection with acetic acid (VIA) and rapid human papillomavirus (HPV)-based screening tests offer promise for scaling up prevention services. Integrating HPV screening with VIA in "screen-and-treat-or-refer" programs offers the dual benefits of HPV screening to maximize detection and using VIA to triage for advanced lesions/cancer, as well as a pelvic exam to address other gynecologic issues. A major issue in LMICs is coinfection with human immunodeficiency virus (HIV) and HPV, which further increases the risk for cervical cancer and marks a population with perhaps the greatest need of cervical cancer prevention. Public-private partnerships to enhance the availability of cervical cancer prevention services within HIV/AIDS care delivery platforms through initiatives such as Pink Ribbon Red Ribbon present an historic opportunity to expand cervical cancer screening in LMICs.