Efficacy of vaccination against HPV infections to prevent cervical cancer in France: present assessment and pathways to improve vaccination policies

Current cancer burden in China: epidemiology, etiology, and prevention

Cancer has become the most common cause of death in China. Owing to rapid economic development, improved livelihood, and shifts in risk factors, cancer epidemiology has experienced substantial changes during the past several decades. In this review, we aim to describe the current cancer epidemiology of the main types of cancer in China, report major risk factors associated with cancer development, and summarize the contributions of the Chinese government to controlling the cancer burden. A total of 4,064,000 new cases were diagnosed in China in 2016. The most frequent types are lung cancer (828,100; 20.4%), colorectal cancer (408,000; 10.0%), and gastric cancer (396,500; 9.8%). Lung (657,000; 27.2%), liver (336,400, 13.9%), and stomach (288,500; 12.0%) cancers are the 3 most deadly cancers in the general population. The 5-year survival rate for cancer has dramatically increased in recent decades. However, liver and particularly pancreatic cancers still have the poorest prognosis. The main modifiable risk factors associated with cancer development include infectious agents, smoking, alcohol consumption, obesity, unhealthful dietary habits, and inadequate physical activity. The Chinese government has made unremitting efforts to decrease the cancer burden, including cancer education and investment in cancer screening programs.

Assessing the epidemiological impact on cervical cancer of switching from 4-valent to 9-valent HPV vaccine within a gender-neutral vaccination programme in Switzerland

BACKGROUND

An infection with high-risk human papillomavirus (HPV) is the obligatory aetiological factor for the development of cervical cancer. In Switzerland, the prevention strategy for cervical cancer is based on primary prevention via HPV vaccination and secondary prevention with an opportunistic screening programme for precancerous lesions. Vaccination is recommended to 11-26 years old male and female persons. The objective of the study was to assess the epidemiological impact on cervical cancer of switching from the currently implemented programme with the 4-valent vaccine to the 9-valent vaccine, in an 11-26 years old gender-neutral vaccination programme in Switzerland.

METHODS

A previously validated dynamic transmission model of HPV infections was adapted and calibrated to the Swiss setting assuming an 80% coverage rate in HPV-vaccination and lifelong vaccine type-specific protection. A gender-neutral vaccination programme (males and females) for 11-26 years old with a 9-valent HPV vaccine was compared with the current 11-26 years old gender-neutral 4-valent vaccination programme. Sensitivity analyses were conducted in order to test the impact of lower vaccination coverage rates and a shorter duration of protection on the model outcomes.

RESULTS

In Switzerland, a 9-valent gender-neutral vaccination programme would result in an additional prevention of 2979 cervical cancer cases, 13,862 CIN3 and 15,000 CIN2 cases, compared with the 4-valent gender-neutral vaccination programme over 100 years. These additional disease cases avoided would correspond to a 24, 36 and 48% cumulative incidence decrease in cervical cancer, CIN3 and CIN2 cases, respectively. It would also prevent additional 741 cervical cancer-related deaths over 100 years. A substantial additional reduction in cervical cancer and precancerous lesions burden is still observed when varying the vaccination coverage rate from 30 to 60% or reducing the duration of protection from lifelong to 20 years.

CONCLUSIONS

The switch to the 9-valent vaccine in Switzerland to prevent cervical diseases showed an important contribution in terms of public health impact compared with the 4-valent vaccine in an 11-26 years old gender-neutral population, even with very conservative assumptions such as low coverage rates or low duration of protection and limiting analysis to only cervical disease.

Schoolteachers' experiences of implementing school-based vaccination programs against human papillomavirus in a Chinese community: a qualitative study

Background

Cervical cancer was the fourth most common cancer among women worldwide in 2012 and was the eighth most common cancer in 2014 and the eighth greatest cause of female cancer deaths in Hong Kong in 2015. Human papillomavirus (HPV) vaccination has been clinically documented to have a high efficacy in reducing HPV-related cervical intraepithelial neoplasia incidence. Therefore, receiving vaccination is a crucial public health measure to reduce disease burden. Significant others, such as schools and schoolteachers, have prominent influence in shaping adolescents’ health perceptions and behavior. Therefore, the perspective of schools and schoolteachers regarding vaccination can significantly influence students’ acceptance and accessibility of the vaccine. However, few studies have analyzed the perceptions of schoolteachers toward HPV vaccination, and even fewer have concerned how schoolteachers’ perceptions influence their schools’ motivation in implementing school-based HPV vaccination programs. This study was thus conducted to fill this literature gap.

Methods

With a Chinese community as the field site of this study, a qualitative approach of five focus group interviews was conducted with 35 schoolteachers from five primary and eight secondary schools in Hong Kong between July 2014 and January 2015. Thematic content analysis was used for data analysis.

Results

Perceptual, institutional, student and parental, and collaborator barriers interacted to discourage the sampled schoolteachers from organizing school-based HPV vaccination programs. Lack of knowledge regarding HPV vaccination, perception of HPV vaccination as inappropriate given the students’ age, violation of traditional cultural values, lack of perceived needs and perceived risk, opposition from schools, low priority of HPV vaccination over other health education topics, lack of government support, lack of interest from parents and students, and lack of confidence in implementing organizations, all were the mentioned barriers.

Conclusions

The sampled schoolteachers were demotivated to organize school-based HPV vaccination programs because of their perceptions and various social and cultural factors. As significant influencers of adolescent students, schoolteachers and schools should receive more support and information on organizing school-based HPV vaccination programs in the future.

Decline of mortality from cervical cancer

OBJECTIVE

To describe occurrences of mortality due to cervical cancer in Recife (PE), in northeastern Brazil.

METHOD

This was a time-series ecological study using data from the Mortality Information System (SIM) regarding the total number of deaths due to cervical cancer (C53 ICD10) that occurred between 2000 and 2012.

RESULTS

It was observed that the risk of death due to this form of cancer was higher among women over 60 years of age, those of mixed skin color (53.24%), those who only worked at home (63.16%) and those who did not have a partner (44.32%).

CONCLUSION

Additional efforts towards maintaining early detection and health education programs and towards using therapeutic strategies of greater efficiency are needed, given that mortality due to this form of cancer is considered avoidable when diagnosed early.

Distribution of Carcinogenic Human Papillomavirus Genotypes and Association to Cervical Lesions among Women in Fez (Morocco)

OBJECTIVES

To determine the distribution of cervical high-risk human papillomavirus genotypes and their association to cellular abnormalities in women from Fez and its neighborhood.

METHODS

Women attending the Hassan II University Hospital for cervical pap smears were recruited after an informed consent. Interviews and two cervical samples were performed for each woman. Cervical samples were used for cytological analysis and HPV DNA detection. HPV was typed using a method based on multiplex PCR with fluorescently labeled specific primers followed by capillary electrophoresis. The study was approved by the ethics committee of the Faculty of Medicine and Pharmacy of Fez.

RESULTS

The HPV prevalence in the studied population was 43.1% and the most prevalent types were HPV 53 (23 cases); HPV 16 (20 cases); HPV 35 (18 cases); HPV 51 (10 cases) and HPV 56 (7 cases). From the 619 confirmed pap smears, 20% were abnormal. The cytological abnormalities were significantly associated to HPV infection, women age, number of pregnancies and parity (p < 0.05).

CONCLUSION

More attention should be given to HPV in Morocco because it represents an important public health concern. The distribution of carcinogenic HPV types in the studied population is different from the data in other regions but epidemiological studies in other Moroccan regions are required.

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.

Rastreamento do câncer do colo do útero no Estado do Maranhão, Brasil

O objetivo do estudo foi analisar o rastreamento do câncer do colo do útero no Maranhão, através dos dados do Sistema de Informação do Câncer do Colo do Útero (Siscolo). Foi realizado um estudo descritivo retrospectivo, com dados secundários dos 139.505 exames citopatológicos registrados no Siscolo do Maranhão, no ano de 2011. As variáveis: idade, escolaridade, adequabilidade do material, epitélios representados, microbiologia e alterações celulares detectadas ao exame citopatológico foram selecionadas. A faixa etária entre 25 a 29 anos e o ensino fundamental incompleto foram os mais frequentes. Os agentes microbiológicos mais comuns foram os bacilos (52,8%), cocos (45,5%) e Lactobacillus sp (32,6%). A inflamação foi a alteração celular benigna mais frequente (86,3%). As lesões intraepiteliais de baixo grau foram as atipias em células escamosas mais prevalentes (0,6%), seguidas pela lesão intraepitelial de alto grau (0,2%). O carcinoma epidermoide foi observado em 0,003% e o adenocarcinoma em 0,006%. O Siscolo revelou-se uma ferramenta útil para conhecer aspectos relacionados ao rastreamento do câncer do colo uterino, o que poderá guiar ações para reduzir a incidência e mortalidade por este câncer.

HPV vaccination coverage in French girls attending middle and high schools: a declarative cross sectional study in the department of Côte d'Or

OBJECTIVES

To assess human papillomavirus prophylactic vaccine coverage among a representative population of French girls, aged 14 years and above, attending middle and high schools, and to determine factors associated with the initiation and completion of the vaccination protocol.

STUDY DESIGN

This cross-sectional study, designed with cluster sampling, was conducted from October 2010 to May 2011, in 29 schools in the department of Côte d'Or, France. The schools were randomized according to their status (public or private) and location (rural or urban). Two classes per level were then included. All analyses were stratified on age.

RESULTS

948 questionnaires were collected (87.9% participation). Mean age was 15.2 years (SD=1.3), ranging between 14 and 19. Only 31.7% of 14-year-old girls and 61.4% of girls aged 15 and above initiated vaccination (one dose), and 7.8% of 14-year-old girls and 48.5% of girls aged 15 and above completed it (three doses). An urban school location and a physician's recommendation were independently associated with vaccination initiation in girls aged 14. In girls aged 15 and above, the parents' socioeconomic status, the family composition and a recommendation by a physician were independently associated with vaccination initiation. Once vaccination had been initiated, girls who attended private school, who belonged to families with higher outcomes, who lived with a single parent or who smoked were less likely to complete the vaccination protocol.

CONCLUSION

HPV prophylactic vaccine coverage in girls attending school in Côte d'Or appears to be low. Physicians play a major role in vaccine acceptance.

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.

A novel method to value real options in health care: the case of a multicohort human papillomavirus vaccination strategy

BACKGROUND

A large number of economic evaluations have already confirmed the cost-effectiveness of different human papillomavirus (HPV) vaccination strategies. Standard analyses might not capture the full economic value of novel vaccination programs because the cost-effectiveness paradigm fails to take into account the value of active management. Management decisions can be seen as real options, a term used to refer to the application of option pricing theory to the valuation of investments in nonfinancial assets in which much of the value is attributable to flexibility and learning over time.

OBJECTIVE

The aim of this article was to discuss the potential advantages shown by using the payoff method in the valuation of the cost-effectiveness of competing HPV immunization programs.

METHODS

This was the first study, to the best of our knowledge, to use the payoff method to determine the real option values of 4 different HPV vaccination strategies targeting female subjects aged 12, 15, 18, and 25 years. The payoff method derives the real option value from the triangular payoff distribution of the project's net present value, which is treated as a triangular fuzzy number. To inform the real option model, cost-effectiveness data were derived from an empirically calibrated Bayesian model designed to assess the cost-effectiveness of a multicohort HPV vaccination strategy in the context of the current cervical cancer screening program in Italy. A net health benefit approach was used to calculate the expected fuzzy net present value for each of the 4 vaccination strategies evaluated.

RESULTS

Costs per quality-adjusted life-year gained seemed to be related to the number of cohorts targeted: a single cohort of girls aged 12 years (€10,955 [95% CI, -1,021 to 28,212]) revealed the lowest cost among the 4 alternative strategies evaluated. The real option valuation challenged the cost-effectiveness dominance of a single cohort of 12-year-old girls. The simultaneous vaccination of 2 cohorts of girls aged 12 and 15 years yielded a real option value (€17,723) equivalent to that attributed to a single cohort of 12-year-old girls (€17,460).

CONCLUSIONS

The payoff method showed distinctive advantages in the valuation of the cost-effectiveness of competing health care interventions, essentially determined by the replacement of the nonfuzzy numbers that are commonly used in cost-effectiveness analysis models, with fuzzy numbers as an input to inform the real option pricing method. The real option approach to value uncertainty makes policy making in health care an evolutionary process and creates a new "space" for decision-making choices.

Detection and genotyping of human papillomavirus by real-time PCR assay

BACKGROUND

Diagnosis of human papillomavirus (HPV) disease remains a challenge due to several factors related to the cost, the workload of available commercial assays to detect and genotype HPV, and to the low prevalence of infected patients.

OBJECTIVE

Our study aimed to develop a real-time PCR, based on SPF10 primers, in order to combine HPV-DNA detection and genotype identification avoiding the negative samples.

STUDY DESIGN

Validation of SYBR-green based SPF10 real-time PCR on HPV-DNA plasmids followed by the investigation of the viral status in 92 samples from oropharyngeal (94%) cutaneous biopsies (3%) and anal smears (3%) which had previously been HPV-genotyped by LiPA hybridization. In-house HPV viral loads were performed to evaluate the SPF10 real-time PCR sensitivity.

RESULTS

Data showed that 100% of HPV plasmids, assessable by LiPA hybridization, were detected and genotyped appropriately after SPF10 real-time PCR assays. These results defined a range of melting temperature peaks for HPV positivity by real-time PCR. The efficient determination of the presence of HPV-DNA by SPF10 real-time PCR was validated for 98% of clinical samples compared to commercial method. Discordant results were due to a low HPV-DNA amount and to a supplementary HPV genotype identified. The SPF10 real-time PCR sensitivity was evaluated between 1 and 10 copies/10(3)cells using in-house HPV (6, 11 and 16) viral load assays.

CONCLUSION

The real-time PCR method was efficient in combining screening and genotyping of HPV-DNA. Cost and workload reduction by SPF10 real-time PCR approach may facilitate earlier diagnosis and clinical management of HPV infected patients.

[Innate and adaptative immunity of the female genital tract]

Most of molecules and cells involved in both types, innate and adaptive immunity are present within the feminine genital tract. This article attempts to list some of the various actors involved in these immunities, essentially at the vaginal level and to illustrate their implications in the most frequent pathologies. Among these molecules: defensins, collectins lysozyme, lactoferrin, calprotectin, SLP1, HSP and many others as well as Toll receptors and immunoglobulins (IgG and IgA) play a major role. Epithelial cells, antigen presenting cells, lymphocytes T, B, NK also contribute efficiently to the defenses in a coordinated way partially under the influence of sex hormones. The therapeutic perspectives, of which vaccines are briefly mentioned.