Gender-neutral HPV elimination, cervical cancer screening, and treatment: Experience from Bhutan

Population-level cancer screening and cancer care in Bhutan, 2020-2023: a review

Screening of cancers is an important intervention in reducing the incidence and mortality related to cancers. Bhutan is one small country that is witnessing an increasing incidence and mortality related to cancers. The government implemented a time-bound population-level screening for gastric, cervical and breast cancers from 2020 to 2023 with an overall coverage of 91.2% of the eligible population. Among 370,225 individuals screened for H pylori, 32.4% tested positive; among 53,182 who underwent upper gastrointestinal endoscopy and biopsy, 255 (0.07%) had gastric cancer. Among 10,749 tested for HPV DNA, 9.3% were positive; among 9887 evaluated with colposcopy and biopsy, 154 (0.13%) had cervical cancer. For breast cancer screening, 72,283 underwent clinical breast examination, 845 mammography and cancer was detected in 73 (0.10%) individuals. In this article, we review how Bhutan implemented a population-level cancer screening programme with on boarding of multiple stakeholders and the participation of people across all districts.

Cancer screening programs in South-east Asia and Western Pacific

BACKGROUND

The burden of cancer can be altered by screening. The field of cancer screening is constantly evolving; from the initiation of program for new cancer types as well as exploring innovative screening strategies (e.g. new screening tests). The aim of this study was to perform a landscape analysis of existing cancer screening programs in South-East Asia and the Western Pacific.

METHODS

We conducted an overview of cancer screening in the region with the goal of summarizing current designs of cancer screening programs. First, a selective narrative literature review was used as an exploration to identify countries with organized screening programs. Second, representatives of each country with an organized program were approached and asked to provide relevant information on the organizations of their national or regional cancer screening program.

RESULTS

There was wide variation in the screening strategies offered in the considered region with only eight programs identified as having an organized design. The majority of these programs did not meet all the essential criteria for being organized screening. The greatest variation was observed in the starting and stopping ages.

CONCLUSIONS

Essential criteria of organized screening are missed. Improving organization is crucial to ensure that the beneficial effects of screening are achieved in the long-term. It is strongly recommended to consider a regional cancer screening network.

Foxo3a-Mediated DNMT3B Impedes Cervical Cancer Cell Proliferation and Migration Capacities through Suppressing PTEN Promoter Methylation

OBJECTIVE

Cervical cancer is linked with the constitutive activation of growth factors and gene mutations-induced pro-survival signaling pathways. Herein, we purposed to explore the possible molecular mechanism of Foxo3a-mediated DNMT3B in the proliferation and migration of cervical cancer cells via mediating the PTEN promoter methylation.

METHODS

Foxo3a expression in cervical cancer was tested by qRT-PCR and western blot experiments. The cervical cancer cell biological functions with overexpression of Foxo3a were evaluated by CCK-8 assay, Transwell experiment, and flow cytometry, respectively. MS-PCR was utilized for testing the PTEN methylation levels, and ChIP experiment was implemented for evaluating the enrichment of DNMT3B in the PTEN promoter region and the binding of Foxo3a and DNMT3B. The PTEN methylation and interference with Foxo3a expression were performed in cervical cancer cells, and then their impacts on cervical cancer cell biological functions were observed.

RESULTS

FOXO3a was expressed at a low level in cervical cancer, and its overexpression contributed to a reduction in cell proliferative, migratory and invasive capabilities, and an elevation in apoptosis rate. Foxo3a blocked its methylation with the PTEN promoter by repressing DNMT3B activity. Upon treatment with methyltransferase inhibitor (5-aza-dc), the malignant phenotypes of cervical cancer cells were diminished. 5-aza-dc neutralized the impacts of silencing Foxo3a on malignant phenotypes.

CONCLUSION

This research underlines that Foxo3a blocks its methylation with the PTEN promoter by inhibiting DNMT3B activity, which subsequently impedes cervical cancer cell progression.

Relationship between vaginal microecological changes and oncogene E6/E7 and high-risk human papillomavirus infection

High-risk (HR)-human papillomavirus (HPV) is the leading cause of precancerous cervical lesions in patients with chronic untreated infection. We investigated the relationships among several vaginal microbiological alterations, oncogene E6/E7 expression, and HR-HPV. A total of 1327 women who underwent HPV screening, vaginal microecology determination, and fluid-based thin-layer cytological test were enrolled and classified into the HPV-negative group, the low-risk (LR)-HPV-positive group, and the HR-HPV-positive group. The status of cervical HPV infection, vaginal microecology, and E6/E7 mRNA expression were examined sequentially. The effect of HR-HPV infection on cervical cancer (CC) was meticulously assessed, and associations between HR-HPV infection and vaginal microecology and E6/E7 mRNA were identified. In total 548/1327 patients were HPV positive, including LR-HPV infection (N = 132) and HR-HPV infection (N = 416). Patients in the HR-HPV positive group revealed higher detection rates of bacterial vaginosis (BV), trichomonal vaginitis (TV), and vulvovaginal candidiasis (VVC) relative to the HPV negative group. A higher E6/E7 mRNA expression was identified in HR-HPV patients compared to LR-HPV patients. BV and E6/E7 mRNA were classified as independent risk factors for HR-HPV infection. Patients with HR-HPV infection were more susceptible to CC development. Overall, BV and E6/E7 mRNA expression were identified as independent risk factors for HR-HPV infection.IMPACT STATEMENTWhat is already known on this subject? Through literature review, we found that vaginal ecological changes increase the risk of HPV infection, and HPV persistent infection is an important risk factor for cervical precancerous lesions and cervical cancer. In addition, HPV gene E6/E7 is expressed in HPV-positive cervical cancer cells, which is related to cell malignant transformation and even tumorigenesis.What do the results of this study add? This study further revealed that bacterial vaginosis (BV) and E6/E7 mRNA were independently correlated with HR-HPV infection, and HR-HPV infection increased the risk of cervical cancer.What are the implications of these findings for clinical practice and/or further research? E6/E7 mRNA detection may be used as a new auxiliary diagnostic index for HR-HPV infection. In addition, this study provides a reference for whether the restoration of vaginal microecological balance in patients with BV undergoing clinical treatment is conducive to HR-HPV regression, and provides theoretical support for the prevention and control of cervical cancer microecological approach and the occurrence and development of cervical cancer.

Human Papillomavirus Epidemiology and Prevention: Is There Still a Gender Gap?

BACKGROUND AND AIM

Human papillomavirus (HPV) is sexually transmitted, one of the three most common sexually transmitted infections (STIs) in both males and females, and the most common viral STI. A crucial public health strategy to protect people against HPV is vaccination, which has shown its effectiveness in preventing HPV-related diseases. Presently, three types of vaccines are available (bivalent, quadrivalent, and nonvalent), and they all target the two most oncogenic virus genotypes (HPV 16 and 18). In recent years, the need to implement vaccination programmes that include all genders has been discussed in order to achieve herd immunity against HPV. To date, only a few countries have included young males in their vaccination programmes. Thus, our objective with this review is to provide an overview of the epidemiology of HPV and HPV prevention strategies and report the latest findings from the scientific literature.

Gender neutral HPV vaccination programs: Reconsidering policies to expand cancer prevention globally

Human papillomavirus (HPV) infection is responsible for many cancers in both women and men. Cervical cancer, caused by HPV, is the fourth most common cancer among women worldwide, even though it is one of the most preventable cancers. Prevention efforts include HPV vaccination, however these programs remain nascent in many countries. In 2020 the World Health Assembly adopted the Global Strategy for cervical cancer elimination including a goal to fully vaccinate 90% of girls with the HPV vaccine by the age of 15. However, very few countries have reached even 70% coverage. Increased vaccine availability in the future may allow the opportunity to vaccinate more people. This could add to the feasibility of introducing gender-neutral HPV vaccination programs. Adopting a gender-neutral HPV vaccine approach will reduce HPV infections transmitted among the population, combat misinformation, minimize vaccine-related stigma, and promote gender equity. We propose approaching programmatic research through a gender-neutral lens to reduce HPV infections and cancers and promote gender equality. In order to design more effective policies and programs, a better understanding of the perspectives of clients, clinicians, community leaders, and policy-makers is needed. A clear, multi-level understanding of these stakeholders' views will facilitate the development of target policy and programs aimed at addressing common barriers and optimizing uptake. Given the benefit of developing gender-neutral HPV vaccination programs to eliminate cervical cancer and address other HPV associated cancers, we must build knowledge through implementation research around this topic to inform policy-makers and funders for future policy shifts.

Expression and Prognostic Significance of PDIA3 in Cervical Cancer

To investigate the expression of protein disulfide isomerase A3 (PDIA3/ERP57) in cervical cancer and its clinical prognostic significance as well as its function and possible action mechanism in the progression of cervical cancer. Based on TIMER2.0 database, the human protein map (Human Protein Atlas) was used to determine the expression level of PDIA3 protein for the analysis of PDIA3 expression in 39 The Cancer Genome Atlas (TCGA) tumors. The PDIA3 expression in cervical cancer tissues in the TCGA and Genotype-Tissue Expression databases was further verified based on the GEPIA2 database to analyze the relationship between the PDIA3 expression and the pathological stage of cervical cancer patients. Immunohistochemistry was used to detect the PDIA3 expression in cervical cancer tissue microarray, including 111 cancer tissue samples and 24 adjacent cancer tissue samples, and the relationship between PDIA3 protein expression and clinical characteristics of patients with cervical cancer was analyzed. The Kaplan–Meier method and log-rank test were used for survival analysis. Based on the cBioPortal database, the Spearman's and Pearson's methods were used to analyze the correlation between PDIA3 expression and DNA methylation. The correlation between PDIA3 expression and the infiltration levels of each immune cell in cervical cancer was evaluated. The STRING was used to construct protein interaction network. Based on LinkedOmics database, the Spearman's method was used to analyze the co-expressed genes of PDIA3 in TCGA cervical cancer. The gene ontology functional enrichment analysis was performed on Top 50 differentially co-expressed genes based on DAVID database. The PDIA3 expression in cervical cancer tissues was significantly higher than that in normal tissues, which (F = 2.74, PR (>F) = 0.0436) was significantly increased with the progression of tumor stage, and PDIA3 showed strong immunoreactivity in cervical cancer tissues. In cervical cancer patients, overall survival (P = 0.014), disease-specific survival (P = 0.013), disease-free interval (P = 0.023), and progression-free interval (P = 0.001) in those with high expression of PDIA3 were significantly lower than those with low expression, suggesting that high expression of PDIA3 was associated with poor prognosis. In cervical cancer, high expression of PDIA3 was associated with DNA methylation and negatively correlated with B cell memory (r = −0.132, P = 0.021), T cell regulatory (r = −0.127, P = 0.026), monocytes (r = −0.204, P = 0), and macrophages M2 (r = −0.142, P = 0.013), whereas positively correlated with levels of NK cell activated (r = 0.162, P = 0.005) and mast cells activated (r = 0.119, P = 0.037). The genes positively correlated with PDIA3 expression included HSPA5 and PPIB, which were mainly enriched in biological processes, such as endoplasmic reticulum (ER) protein folding and ER stress response. PDIA3 can be used as a marker of poor prognosis of cervical cancer. The expression level of PDIA3 is closely related to the survival and prognosis of cervical cancer patients, DNA methylation, and immune cell infiltration.