Prophylactic human papillomavirus vaccination and primary prevention of cervical cancer: issues and challenges

Peptide-Based Nanovaccines in the Treatment of Cervical Cancer: A Review of Recent Advances

Persistent infection with high-risk human papillomaviruses (HPVs), such as HPV-16 and HPV-18, can induce cervical cancer in humans. The disease carries high morbidity and mortality among females worldwide. Inoculation with prophylactic HPV vaccines, such as Gardasil^® or Cervarix^®, is the predominant method of preventing cervical cancer in females 6 to 26 years of age. However, despite the availability of commercial prophylactic HPV vaccines, no therapeutic HPV vaccines to eliminate existing HPV infections have been approved. Peptide-based vaccines, which form one of the most potent vaccine platforms, have been broadly investigated to overcome this shortcoming. Peptide-based vaccines are especially effective in inducing cellular immune responses and eradicating tumor cells when combined with nanoscale adjuvant particles and delivery systems. This review summarizes progress in the development of peptide-based nanovaccines against HPV infection.

Prevalence and Characteristics of hrHPV Infection among 414,540 Women: A Multicenter Study in Central and Eastern China

Objectives: Understanding the prevalence and characteristics of high-risk human papillomavirus (hrHPV) with the large-scale multicenter data based on a US FDA-approved testing method is important to guide ongoing vaccination programs in China.

Methods: We conducted a retrospective observational study based on data from 11 large hospitals in central and eastern China. From October 1st, 2012 to December 31st, 2016, a total of 480,034 cervical specimens were collected, and 414,540 eligible participants (14-80 years, mean age 39.9 years) were included and tested using Cervista High-Risk HPV Assay (Hologic Inc., Bedford, Mass, USA).

Results: The overall hrHPV prevalence in this study was 17.8% (73,713/414,540), with Wuhan slightly higher than Zhejiang (18.6% vs. 17.6%, P < 0.001). The prevalence showed a declining trend from 2012 to 2016. The most common hrHPV group was A9 (61.7%), followed by A5/A6 (29.4%) and A7 (25.6%). A U-shaped curve was observed for age-specific hrHPV prevalence: ≤19 years and ≥50 years were higher than other age groups.

Conclusion: In pre-vaccination period, A9 was the most dominant hrHPV group, and infections were most likely to occur at younger and older ages. The prevalence of hrHPV varied by cities and age groups, suggesting vaccination programs should be propagated in a population-specific approach.

Suppressive Effects of EGCG on Cervical Cancer

Cervical cancer is the fourth most common gynecological cancer worldwide. Although prophylactic vaccination presents the most effective method for cervical cancer prevention, chemotherapy is still the primary invasive intervention. It is urgent to exploit low-toxic natural anticancer drugs on account of high cytotoxicity and side-effects of conventional agents. As a natural product, (-)-epigallocatechingallate (EGCG) has abilities in anti-proliferation, anti-metastasis and pro-apoptosis of cervical cancer cells. Moreover, EGCG also has pharmaceutical synergistic effects with conventional agents such as cisplatin (CDDP) and bleomycin (BLM). The underlying mechanisms of EGCG suppressive effects on cervical cancer are reviewed in this article. Further research directions and ambiguous results are also discussed.

The Uptake of Human Papillomavirus Vaccination and Its Associated Factors Among Adolescents: A Systematic Review

Background: The purpose of this review was to explore the uptake of the human papillomavirus (HPV) vaccination, its associated factors, and the facilitators of and barriers to HPV vaccination among adolescents. Methods: A comprehensive literature search was conducted through 5 electronic databases, including PubMed, CINAHL, Cochrane Library, Medline, and PsycInfo from January 2006 to March 2015 for studies examining the uptake, awareness, knowledge, acceptability, and intention of adolescents with regard to HPV vaccination. Results: Twenty-eight studies were identified and included. The HPV vaccination uptake rate (at least 1 dose) varied significantly among countries, ranging from 2.4% to 94.4%. Scotland achieved the highest uptake of all the studies included in this review, while Hong Kong had the lowest, at 2.4% to 9.1%. This review also showed that adolescents had limited awareness and knowledge of HPV infections and vaccines, even 10 years after the vaccine had become available. Conclusions: It is recommended that barriers to the uptake of the vaccine should be addressed, and that school-based sexual health education of HPV infection and vaccine promotion should be reinforced.

Awareness and knowledge about human papillomavirus vaccination and its acceptance in China: a meta-analysis of 58 observational studies

Background

The human papillomavirus (HPV) vaccines have been widely introduced in immunization programs worldwide, however, it is not accepted in mainland China. We aimed to investigate the awareness and knowledge about HPV vaccines and explore the acceptability of vaccination among the Chinese population.

Methods

A meta-analysis was conducted across two English (PubMed, EMBASE) and three Chinese (China National Knowledge Infrastructure, Wan Fang Database and VIP Database for Chinese Technical Periodicals) electronic databases in order to identify HPV vaccination studies conducted in mainland China. We conducted and reported the analysis in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results

Fifty-eight unique studies representing 19 provinces and municipalities in mainland China were assessed. The pooled awareness and knowledge rates about HPV vaccination were 15.95 % (95 % CI: 12.87–19.29, I² = 98.9 %) and 17.55 % (95 % CI: 12.38–24.88, I² = 99.8 %), respectively. The female population (17.39 %; 95 % CI: 13.06–22.20, I² = 98.8 %) and mixed population (18.55 %; 95 % CI: 14.14–23.42, I² = 98.8 %) exhibited higher HPV vaccine awareness than the male population (1.82 %; 95 % CI: 0.50–11.20, I² = 98.5 %). Populations of mixed ethnicity had lower HPV vaccine awareness (9.61 %; 95 % CI: 5.95–14.03, I² = 99.0 %) than the Han population (20.17 %; 95 % CI: 16.42–24.20, I² = 98.3 %). Among different regions, the HPV vaccine awareness was higher in EDA (17.57 %; 95 % CI: 13.36–22.21, I² = 98.0 %) and CLDA (17.78 %; 95 % CI: 12.18–24.19, I² = 97.6 %) than in WUDA (1.80 %; 95 % CI: 0.02–6.33, I² = 98.9 %). Furthermore, 67.25 % (95 % CI: 58.75–75.21, I² = 99.8 %) of participants were willing to be vaccinated, while this number was lower for their daughters (60.32 %; 95 % CI: 51.25–69.04, I² = 99.2 %). The general adult population (64.72 %; 95 % CI: 55.57–73.36, I² = 99.2 %) was more willing to vaccinate their daughters than the parent population (33.78 %; 95 % CI: 26.26–41.74, I² = 88.3 %). Safety (50.46 %; 95 % CI: 40.00–60.89, I² = 96.6 %) was the main concern about vaccination among the adult population whereas the safety and efficacy (68.19 %; 95 % CI: 53.13–81.52, I² = 98.6 %) were the main concerns for unwillingness to vaccinate their daughters.

Conclusions

Low HPV vaccine awareness and knowledge was observed among the Chinese population. HPV vaccine awareness differed across sexes, ethnicities, and regions. Given the limited quality and number of studies included, further research with improved study designis necessary.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-2873-8) contains supplementary material, which is available to authorized users.

Frequency of precancerous changes and cervical cancer recorded in three health centres in tuzla canton in period 2010-2011

Cervical cancer is the second most common cancer in the world and the leading cause of death. Frequency and mortality are significantly reduced thanks to cytological Papanicolau test (PAP). Regular PAP test can reduce approximately 80% of cases of this cancer

The role of inflammation in cervical cancer

Knowledge regarding cervical cancer and human papillomavirus is expanding rapidly. Inflammation subsequent to viral infection is a driving force that accelerates cancer development. The infiltrated immune cells and their secretory cytokines along with chemokines and growth factors greatly contribute the malignant traits of cervical cancer. A better understanding of the mechanisms related to inflammation and cancer progression in terms of pathogen survival, cancer development, progression, and metastasis will lead to innovative approach for treating cancer.

Role of human papillomaviruses in esophageal carcinoma: an updated systematic review from 1982 to 2013

ABSTRACT: 

Tobacco, alcohol and betel quid are known etiological agents of esophageal squamous cell carcinoma (ESCC). A meta-analysis in 2012 and a literature update (1982–August 2013) identified 159 studies with a total of 11,310 ESCCs tested for the presence of human papillomaviruses (HPVs). HPV DNA was present in 30.3% of fESCCs, with substantial geographic differences. A recent meta-analysis of 21 case–control studies investigating the HPV–ESCC association showed that HPVs increase the risk of ESCC at least threefold. Vaccine-preventable HPV-16 and HPV-18 are the most commonly identified HPV types in ESCC in both low- and high-incidence settings. HPVs should now be seriously considered as etiological agents for at least a subset of ESCC, and more studies are needed to provide conclusive evidence that HPVs cause ESCC.

Human papillomavirus vaccination: current indications and future directions

Human papillomavirus (HPV) is one of the most common sexually transmitted infections affecting both men and women worldwide. The development of the prophylactic HPV vaccines is a significant pharmaceutical innovation with potential to reduce HPV-related morbidity. However, barriers to the universal use and acceptability of the HPV vaccines continue to exist in both economically privileged and disadvantaged countries. It may be decades before the impact of preventive vaccines on HPV-related diseases caused by the considerable burden of HPV infections will be seen. Collaborative efforts must continue to promote vaccine implementation.

Screening adolescents and young women

Recent guidelines from multiple organizations stress screening initiation no earlier than the age of 21 years and increased screening intervals for women aged 21 to 29 years. Primary prevention with human papillomavirus vaccination has the potential to significantly affect the development of high-grade cervical lesions, including cancer, and will likely affect screening guidelines in the future.