Epidemiology of Human Papillomavirus Infection and Cervical Cancer and Future Perspectives in Hong Kong, Singapore and Taiwan

A Study of Human Papillomavirus Genotypes Specificity and the Vaccines Introducing System for Korean-Chinese Women in the Yanbian Autonomous Region

Objectives:

Human papillomavirus (HPV) is a major cause of cervical cancer in women. The characteristics of HPV infection vary; therefore, it is necessary to identify the most common HPV genotypes among a group of subjects when introducing a vaccine program. Currently, in the Yanbian Autonomous Region, no HPV vaccinations are not provided, and no data has been reported regarding HPV rates or genotype prevalence. We aimed to find the most suitable HPV vaccine for this region and reasons why no vaccine has been introduced.

Methods:

HPV genotyping of 200 Korean-Chinese women living in the Yanbian Autonomous Region who visited the hospital for annual health examination was done. We also checked main factors necessary for HPV vaccine administrative system; (1) vaccine manufacturers in China, (2) vaccine importers, (3) vaccine suppliers, (4) applicable vaccine laws, (5) the HPV vaccine permit system in Jilin Province, and (6) vaccination hospital facilities-were assessed by direct inquiry and search.

Results:

The results showed that HPV genotypes 52, 58, 16, 53, and 33 were the most common among Korean-Chinese women. These results differed from those previously reported for Korean or Chinese women. All elements necessary for introduction of HPV vaccine were prepared, but there is no HPV vaccination plan based on epidemiological investigation.

Conclusions:

Gardasil® 9 should be the most suitable vaccine for Korean-Chinese women with HPV infection and cervical cancer in this region considering the prevalence of certain genotypes. Governments and medical institutions should take an active stance on HPV vaccination to lower the incidence of cervical cancer here. Our study may serve as an important reference for introducing a Chinese government program designed to prevent cervical cancer.

Menstrual Blood Human Papillomavirus DNA and TAP1 Gene Polymorphisms as Potential Biomarkers for Screening and Monitoring of Cervical Squamous Intraepithelial Lesion

Background

Human papillomavirus (HPV) is a known causative factor in the etiology of cervical cancer.

Methods

HPV DNA genotyping was performed in menstrual blood (MB) collected in napkins from patients with cervical intraepithelial neoplasia (CIN), HPV infection and sexually active apparently normal subjects. In the same patient cohort, MB TAP1 I333V and TAP1 D637G gene polymorphisms were examined.

Results

The sensitivity, specificity, and positive and negative predictive values of HPV DNA in the detection of CIN or HPV infection were 83% (223 of 268), 98% (131 of 134), 99% (223 of 226), and 74% (131 of 176), respectively. Moreover, HPV DNA was found in 24% (28/118) patients who had loop electrosurgical excision procedure treatment and 0% (0/76) HPV infected or CIN1 patient with proven recovery. On the other hand, the risk of developing high-grade CIN was significantly reduced for AG and GG genotypes compared with AA genotype and for carriers with a G allele compared with those with an A allele for both polymorphisms.

Conclusions

MB HPV DNA is a potential noninvasive marker for screening and monitoring of squamous intraepithelial lesion. Together with TAP1 I333V and TAP1 D637G gene polymorphisms, the combined test may be useful for stratifying high-risk patients for better follow-up strategies.

Knowledge, Decision-Making and Acceptance of Human Papilloma Virus Vaccination among Parents of Primary School Students in Kota Bharu, Kelantan, Malaysia

Background: The incidence of cervical cancer in younger women remains high. This is worrisome as it affects future generations. Therefore Malaysia implements human papilloma virus (HPV) vaccination as a national vaccination program. Parents play an important role in determining the success of this HPV vaccination program among schoolaged girls by their compliance. Objective: To assess parental knowledge, decision-making and acceptance of HPV vaccination. Methods: This cross sectional study was conducted among 280 randomly selected parents of primary school students aged 11 in Kota Bharu using a pre-validated self-administered questionnaire to assess knowledge and decision-making with regard to HPV vaccination. Results: Most parents (62%) were shown to have poor knowledge while most decision-making was shared. Age of respondents (adjusted odds ratio ‘AOR’= 1.09; 95% confidence interval ‘CI’= 1.04-1.14; p <0.001) and good knowledge of HPV vaccination (AOR= 16.32; 95% CI= 7.32-36.4; p <0.001) were significantly associated with HPV vaccine acceptance. Conclusion: The majority of parents exhibited poor knowledge which may affect their decision-making and uptake of HPV vaccination among their children. This highlights the need to better educate parents on HPV vaccination.

Risk of cancer in patients with genital warts: A nationwide, population-based cohort study in Taiwan

Background

Condyloma acuminata currently affects around 1% of sexually active adults, and its incidence is increasing. The coexistence of genital warts (GW) and certain cancers and an association between human papillomavirus (HPV) and various malignancies have been reported. Therefore, we conducted this large national study to analyze the risk of malignancies among men and women with GW in Taiwan.

Methods and findings

Between January 2000 and December 2013, approximately 3 million patients were reported to the National Health Insurance Research Database of Taiwan. Of these patients, 21,763 were diagnosed with GW. In the same time period, a total of 213,541 cancer cases were reported to the registry, of which 1002 were recorded among patients with GW. The age-specific incidence rates of GW and standardized incidence ratios (SIRs) of malignancies compared to the general population were calculated. Women acquired GW earlier than men, with a mean age at diagnosis of 32.63±12.78 years. The highest incidence rate for both genders peaked at 20–29 years. Of the 1002 patients with GW and malignancies, the SIR was 1.95 (95%CI 1.83–2.07). The most markedly increased risk was found for HPV-related cancers, with a SIR of 9.74 (95%CI 3.70–15.77). Significantly elevated risks were also noted for smoking-related cancers, anogenital cancers, cervix in situ, colon, rectum, lung, kidney, and prostate cancers. Most cancers developed within 10 years after the diagnosis of GW.

Conclusions

Patients with GW have an increased risk of HPV-related cancers, especially anogenital malignancies in Taiwan. The elevated risk of other cancers highlights differences in exposure and risk factors among patients with GW compared to the general population. Cancer screening and HPV vaccination programs should be emphasized for at-risk patients.

Facilitators and barriers to the acceptance of human papillomavirus (HPV) vaccination among adolescent girls: a comparison between mothers and their adolescent daughters in Hong Kong

BACKGROUND

The aim of this study is to examine knowledge and attitude as facilitators and barriers to the acceptance of HPV vaccination for adolescent girls by mothers and adolescent girls.

METHODS

A cross-sectional survey conducted in Hong Kong in January 2010. Adolescent girls aged 12-18, together with their mothers, were recruited to complete two separate questionnaires with similar questions.

RESULTS

A total of 170 mother-adolescent girl dyads were recruited. When the daughters and mothers were compared, the mothers were found to be more aware of "the risk of becoming infected with HPV through early sexual intercourse," while more daughters than mothers knew that "the HPV virus cannot be cured with antibiotics." Significantly more daughters perceived that they had a "chance of being infected with HPV and getting cervical cancer without the vaccine," while more mothers were concerned that "vaccinating for HPV will cause a girl to be stigmatized as promiscuous" and thought that their "adolescent daughters are too young to receive the HPV vaccine." The major predictive factor for the acceptance of the HPV vaccine among mothers was "The HPV vaccine is safe" (OR = 10.126, 95% CI 2.47-41.54). Among daughters who accepted the vaccine, the predictive factor was "The HPV vaccine can prevent most HPV infections" (OR = 6.274, 95% CI 1.93-20.42).

CONCLUSIONS

The findings provide healthcare professionals with a better understanding of the differences between mothers and adolescent girls in knowledge, attitude, and potential factors associated with acceptance of the HPV vaccine. Health professionals should promote the early prevention of HPV infection and eliminate the stigma surrounding HPV vaccination to increase its acceptance. The government should provide financial support for adolescent girls to receive the vaccination in school.

Pelvic inflammatory disease increases the risk of a second primary malignancy in patients with cervical cancer treated by surgery alone

As the number of long-term cervical cancer survivors continues to increase because of improvements in treatment, concerns about second primary malignancy have grown. The high-risk area of second primary cancers in cervical cancer survivors is the pelvis. Pelvic inflammatory disease (PID) could be a useful marker for gynecological cancers. Thus, we designed a large-scale, nationwide, controlled cohort study to investigate whether PID or other risk factors increased the risk of second primary cancers in patients with cervical cancer treated by surgery alone.Between 2000 and 2010, a total of 24,444 cervical cancer patients were identified using the Registry Data for Catastrophic Illness and the National Health Insurance Research Database (NHIRD) of Taiwan. Patients who received definite surgery were selected. To exclude the effect on second primary malignancy by treatment modalities, all cervical patients who ever having received adjuvant or definite radiotherapy or chemotherapy for primary cervical cancer were excluded. Finally, 3860 cervical cancer patients treated by surgery alone without adjuvant treatments were analyzed.Cox proportional hazards model was used for multivariate analysis and the Kaplan-Meier method was used to assess the cumulative risks. Regarding the incidence of second primary cancers, the standardized incidence ratio (SIR) was used.The median follow-up time was 56.6 months. The 6-year cumulative risk of second primary cancers is 0.16% and 0.12% for PID and without PID, respectively. After adjustment for confounders, age of less than 50 years, the presence of diabetes mellitus, and PID were significantly positivity associated with the risk of second primary cancers. The hazard ratios (HRs) of age less than 50 years, diabetes mellitus, and PID were 1.38 (95% CI = 1.11-2.04), 1.40 (95% CI = 1.06-1.85), and 1.35 (95% CI = 1.00-1.81), respectively. A higher incidence of second primary cancers was observed in the genitals, bladder, and colon.In conclusion, the incidence of second primary cancers was higher in the genitals, bladder, and colon in patients with cervical cancer treated with surgery alone. The patients with PID had a higher risk of second primary cancers.

Incidence, Trends and Ethnic Differences of Oropharyngeal, Anal and Cervical Cancers: Singapore, 1968-2012

In recent decades, several Western countries have reported an increase in oropharyngeal and anal cancers caused by human papillomavirus (HPV). Trends in HPV-associated cancers in Asia have not been as well described. We describe the epidemiology of potentially HPV-related cancers reported to the Singapore Cancer Registry from 1968-2012. Analysis included 998 oropharyngeal squamous cell carcinoma (OPSCC), 183 anal squamous cell carcinoma (ASCC) and 8,019 invasive cervical cancer (ICC) cases. Additionally, 368 anal non-squamous cell carcinoma (ANSCC) and 2,018 non-oropharyngeal head and neck carcinoma (non-OP HNC) cases were included as comparators. Age-standardized incidence rates (ASR) were determined by gender and ethnicity (Chinese, Malay and Indian). Joinpoint regression was used to evaluate annual percentage change (APC) in incidence. OPSCC incidence increased in both genders (men 1993-2012, APC = 1.9%, p<0.001; women 1968-2012, APC = 2.0%, p = 0.01) and was 5 times higher in men than women. In contrast, non-OP HNC incidence declined between 1968-2012 among men (APC = -1.6%, p<0.001) and women (APC = -0.4%, p = 0.06). ASCC and ANSCC were rare (ASR = 0.2 and 0.7 per 100,000 person-years, respectively) and did not change significantly over time except for increasing ANSCCs in men (APC = 2.8%, p<0.001). ICC was the most common HPV-associated cancer (ASR = 19.9 per 100,000 person-years) but declined significantly between 1968-2012 (APC = -2.4%). Incidence of each cancer varied across ethnicities. Similar to trends in Western countries, OPSCC incidence increased in recent years, while non-OP HNC decreased. ICC remains the most common HPV-related cancer in Singapore, but Pap screening programs have led to consistently decreasing incidence.

Distribution of high-risk human papillomavirus genotypes in HPV-infected women in Beijing, China

To investigate the distribution of high-risk human papillomavirus (HPV) genotypes in infected women from Beijing, China, samples were obtained during routine gynecologic examinations and DNA was extracted from the samples, and PCR was performed to distinguish the 13 high-risk HPV subtypes (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68). Samples were obtained from 1160 women (20-75 years old), and 470 cases of high-risk HPV infection were diagnosed. HPV 52, HPV 16, HPV 58, HPV 51, and HPV 39 were the most common genotypes accounting for 22.8%, 22.3%, 20.0%, 14.3%, and 13.6% of cases, respectively. The highest infection rates were found in 20-30 year-old patients (35.1%). HPV 16 infection was the highest in the 31-40 year-old group, and HPV 52, HPV 58, and HPV 39 infections were highest in the 20-30 year-old group. Some patients were infected with multiple high-risk HPV subtypes. Of the 470 patients with positive HPV tests, 65.7% of women were infected with a single high-risk HPV subtype, 23.2%, of women were infected with two high-risk HPV subtypes, 7.7% were infected with three subtypes, and 3.4% of women were infected with more than three high-risk HPV subtypes. In this study, HPV 16 and HPV 52 were the most common subtypes found in patients with cervical lesions.

'Organised' cervical screening 45 years on: How consistent are organised screening practices?

Organised screening programmes have been remarkably successful in reducing incidence and mortality from cervical cancer, while opportunistic screening varies in its effectiveness. Experts recommend that cervical screening or HPV testing be carried out only in the context of an organised programme. We sought to answer the following study questions: What does it mean for a cervical screening programme to be organised? Is there a place for opportunistic screening (in an organised programme)? We reviewed 154 peer-reviewed papers on organised and opportunistic approaches to cervical screening published between 1970 and 2014 to understand how the term 'organised' is used, formally and in practice. We found that despite broad recognition of a prescriptive definition of organisation, in practice the meaning of organisation is much less clear. Our review revealed descriptions of organised programmes that differ significantly from prescribed norms and from each other, and a variety of ways that opportunistic and organised programmes intersect. We describe the breadth of the variation in cervical cancer screening programmes and examine the relationships and overlaps between organised and opportunistic screening. Implications emerging from the review include the need to better understand the breadth of organisation in practice, the drivers and impacts of opportunistic screening and the impact of opportunistic screening on population programme outcomes. Appreciation of the complexity of cervical screening programmes will benefit both screeners and women as programmes are changed to reflect a partially vaccinated population, new evidence and new technologies.

Human papillomavirus genotypes and cervical cancer in northeast Thailand

Human papillomavirus (HPV) is a major cause of cervical cancer. More than 100 HPV genotypes have been identified; however the distribution varies geographically and according to ethnicity. The purpose of this study was to investigate the prevalence and distribution of HPV subtypes among Northeast Thai women. Subjects included 198 cases of SCCA and 198 age-matched, healthy controls. HPV-DNA was amplified by PCR using the consensus primers GP5+/6+ system followed by reverse line blot hybridization genotyping. The prevalence of high-risk HPV infection was 21 (10.1%) and 152 (76.8%) in the controls and in the cases, respectively. High-risk HPV significantly increased the risk for cervical cancer with an OR of 42.4 (95%CI: 22.4-81.4, p<0.001) and an adjusted OR of 40.7-fold (95%CI: 21.5-76.8, p <0.001). HPV-16 was the most prevalent HPV type in the SCCA (56.2%) followed by HPV-58 (17.8%) and HPV-18 (13.6%); whereas HPV-58 (46.4%) was a prominent genotype in the controls followed by HPV-16 (39.3%) and unidentified HPV types (25.0%). These findings indicate that HPV infection remains a critical risk factor for SCCA; particularly, HPV-16, HPV-58 and HPV-18. In order to eradicate cervical cancer, sustained health education, promoted use of prophylactics and a HPV-58 vaccine should be introduced in this region.

HPV vaccination in Hong Kong: uptake and reasons for non-vaccination amongst Chinese adolescent girls

OBJECTIVES

The study aims to determine HPV vaccine uptake (≥ 1 dose) amongst adolescent girls in Hong Kong and to explore the reasons for non-acceptance of the vaccine.

STUDY DESIGN

A total of 1832 secondary school girls (15.5 ± 2.0 years) were randomly surveyed. Their HPV vaccine uptake was estimated, and their reasons for non-vaccination summarised.

RESULTS

A total of 131 (7.2%, 95% CI: 6.0-8.4%) adolescent girls had received the HPV vaccine (≥ 1 dose). Vaccine uptake was positively associated with a higher maternal education level and locally born status. Amongst the non-vaccinated girls, 20.6% had never heard of or knew little about the vaccine, 20.2% 'did not know where to receive', and 17.8% were concerned about the cost.

CONCLUSIONS

The HPV vaccine uptake amongst adolescent girls in Hong Kong is very low. A school-based education and service programme is needed to improve uptake and prevent disparities in the Chinese population.

Human papillomavirus type distribution in invasive cervical cancer and high-grade cervical intraepithelial neoplasia across 5 countries in Asia

OBJECTIVE

Independent, prospective, multicenter, hospital-based cross-sectional studies were conducted across 5 countries in Asia, namely, Malaysia, Vietnam, Singapore, South Korea, and the Philippines. The objectives of these studies were to evaluate the prevalence of human papillomavirus (HPV) types (high risk and others including coinfections) in women with invasive cervical cancer (ICC) and high-grade precancerous lesions.

METHODS

Women older than 21 years with a histologic diagnosis of ICC and cervical intraepithelial neoplasia [CIN 2 or 3 and adenocarcinoma in situ (AIS)] were enrolled. Cervical specimens were reviewed by histopathologists to confirm the presence of ICC or CIN 2/3/AIS lesion and tested with short PCR fragment 10-DNA enzyme immunoassay-line probe assay for 14 oncogenic HPV types and 11 non-oncogenic HPV types. The prevalence of HPV 16, HPV 18, and other high-risk HPV types in ICC [including squamous cell carcinoma (SCC) and adenocarcinoma/adenosquamous carcinoma (ADC/ASC)] and CIN 2/3/AIS was estimated.

RESULTS

In the 5 Asian countries, diagnosis of ICC was confirmed in 500 women [SCC (n = 392) and ADC/ASC (n = 108)], and CIN 2/3/AIS, in 411 women. Human papillomavirus DNA was detected in 93.8% to 97.0% (84.5% for the Philippines) of confirmed ICC cases [94.0%-98.7% of SCC; 87.0%-94.3% (50.0% for the Philippines) of ADC/ASC] and in 93.7% to 100.0% of CIN 2/3/AIS. The most common types observed among ICC cases were HPV 16 (36.8%-61.3%), HPV 18 (12.9%-35.4%), HPV 52 (5.4%-10.3%), and HPV 45 (1.5%-17.2%), whereas among CIN 2/3/AIS cases, HPV 16 (29.7%-46.6%) was the most commonly observed type followed by HPV 52 (17.0%-66.7%) and HPV 58 (8.6%-16.0%).

CONCLUSIONS

This article presents the data on the HPV prevalence, HPV type distribution, and their role in cervical carcinogenesis in 5 Asian countries. These data are of relevance to public health authorities for evaluating the existing and future cervical cancer prevention strategies including HPV-DNA testing-based screening and HPV vaccination in these Asian populations.

Cervical cancer burden and prevention strategies: Asia Oceania perspective

The Asia Oceania region contributes to more than 50% of cervical cancer cases worldwide. Yet cervical cancer is one of few cancers that can be prevented through comprehensive screening for precancerous lesions, with their subsequent treatment. Screening with cervical cytology, a very old technology, has reduced cervical cancer mortality and incidence when applied in comprehensive programs with high coverage and high quality assurance. However, of those countries within this region that have set up such programs, many have been opportunistic, had poor coverage, or inadequate treatment facilities for lesions found. Consequently, they have not seen large reductions in cancer incidence or mortality. Some have therefore adopted visual inspection by acetic acid (VIA) and Lugol's iodine (VILI) or human papillomavirus (HPV) DNA assays for screening. With two safe, immunogenic and efficacious prophylactic vaccines licensed, the way forward to reduction of cervical cancer to becoming uncommon is within reach. Where governments have supported high coverage public-health vaccination programs, reductions in disease burden with shortest incubation (genital warts, high-grade abnormalities) are already being reported. One of the biggest impediments is the cost of vaccines that are affordable to resource-poor countries. Other challenges include, infrastructure for delivery of vaccines, plus general acceptance of vaccination by the community.

The emerging epidemic of estrogen-related cancers in young women in a developing Asian country

The incidence of breast and genital tract cancers is increasing among Taiwanese women, but the age specificity and histopathological features of these cancers have not been determined. We used a descriptive epidemiological method and data from the Taiwan Cancer Registry (1979-2007) to examine secular trends in the age-specific incidences of female breast cancer, three major female genital tract cancers and the histopathological subtypes of these cancers. Age-specific incidence rates in the United States (1978-2002) were used as an external reference, and the incidence rates of all malignancies and of malignant brain tumors were used as internal references. We found that age-adjusted incidence rates of female breast, uterine, and ovarian cancers increased in Taiwan from 1979 to 2007, whereas the incidence of cervical cancer decreased after 1998. The largest increase was observed for ductal and lobular carcinomas of the breast and endometrioid carcinomas of the uterus and ovary in women ≤55 years, all of these tumors show a high prevalence of hormone receptor expressions. In addition, hormone-receptor-positive rates of breast cancer were uniquely higher in younger, as opposed to older, Taiwanese women. These findings indicate that estrogen-related cancers rapidly emerge in young women in Taiwan and that incidence rates are catching up with that of women living in the United States.

Knowledge and beliefs about cervical cancer and human papillomavirus among Taiwanese undergraduate women

PURPOSE/OBJECTIVES

To assess knowledge and attitudes regarding cervical cancer and human papillomavirus (HPV) among undergraduate women in Taiwan.

DESIGN

A descriptive cross-sectional design.

SETTING

Five universities in southern Taiwan.

SAMPLE

953 undergraduate women aged 17-36 years.

METHODS

The self-administered HPV Belief questionnaire was used to collect data on knowledge and beliefs regarding cervical cancer, Pap testing, and HPV.

MAIN RESEARCH VARIABLES

Knowledge, beliefs, cervical cancer, Pap testing, HPV, likelihood of cervical cancer, and HPV infection.

FINDINGS

Seventy percent of participants agreed that cervical cancer could be prevented and was a severe disease, and 80% knew the purpose of Pap testing. Forty-nine percent were aware of HPV. Undergraduate women with an awareness of HPV were more likely to be older, studying a health-related major, have a higher class standing, have a personal history of gynecologic visits, and have had a Pap test. Neither family history of gynecologic cancer nor sexual experience predicted HPV awareness, although sexual experience had a significant association with the knowledge and beliefs of cervical cancer. Most of the undergraduate women believed themselves unlikely to acquire cervical cancer or HPV infection.

CONCLUSIONS

Undergraduate women in Taiwan have limited knowledge of cervical cancer and HPV. Awareness of the likelihood of HPV infection is low among undergraduate women, even those who are sexually active.

IMPLICATIONS FOR NURSING

Educational campaigns focusing on cervical cancer screening and HPV infection are needed, particularly for sexually active undergraduate women.

The impact of cytology screening and HPV vaccination on the burden of cervical cancer

AIM

To evaluate the impact of different strategies of human papillomavirus (HPV) vaccination on the burden of cervical cancer in Singapore.

METHODS

The incidence of cervical cancer was calculated using a Markov model with inputs based on Singapore data for the prevalence of HPV infection, socioeconomic characteristics and screening prevalence. The evaluation was performed for 10 scenarios: no screening, current opportunistic cytology screening, ideal optimal screening, universal adolescent HPV vaccination at 12-years old alone and with catch-up cohorts and combinations of screening and vaccination.

RESULTS

(1) The model prediction showed that cervical cancer cases were reduced by 6.5% using opportunistic screening, by 34.3% using optimized screening and by 63.9% with a universal HPV vaccination at 12 years of age. (2) Adding optimized screening, but not opportunistic screening, to a universal adolescent HPV vaccination program caused a moderate further reduction in cervical cancer cases. (3) No difference was discernable in the impact of vaccination introduction between the age groups <20, 20-24 and 25-29 years old. (4) The time required to halve the incidence of cervical cancer was 42 years for universal vaccination at the age of 12 but could be shortened by including catch-up cohorts of women up to 40-years old.

CONCLUSION

A universal HPV vaccination program introduced between the ages of 12-29 is superior to cytology screening in reducing the burden of cervical cancer. However, in the next four decades of post-vaccination era, optimizing the screening program remains the most important measure for cervical cancer prevention.

Global challenges of implementing human papillomavirus vaccines

Human Papillomavirus vaccines are widely hailed as a sweeping pharmaceutical innovation for the universal benefit of all women. The implementation of the vaccines, however, is far from universal or equitable. Socio-economically marginalized women in emerging and developing, and many advanced economies alike, suffer a disproportionately large burden of cervical cancer. Despite the marketing of Human Papillomavirus vaccines as the solution to cervical cancer, the market authorization (licensing) of the vaccines has not translated into universal equitable access. Vaccine implementation for vulnerable girls and women faces multiple barriers that include high vaccine costs, inadequate delivery infrastructure, and lack of community engagement to generate awareness about cervical cancer and early screening tools. For Human Papillomavirus vaccines to work as a public health solution, the quality-assured delivery of cheaper vaccines must be integrated with strengthened capacity for community-based health education and screening.

Asia oceania guidelines for the implementation of programs for cervical cancer prevention and control

This paper aims to provide evidence-based recommendations for health professionals, to develop a comprehensive cervical cancer program for a clinic, a community, or a country. Ensuring access to healthcare is the responsibility of all societies, and the Asia Oceania Research Organisation in Genital Infections and Neoplasia (AOGIN) is committed to working collaboratively with governments and health professionals to facilitate prevention programs, to protect girls and women from cervical cancer, a disease that globally affects 500,000 and kills nearly 300,000 women annually, just over half of whom are in the Asia Oceania region. We share the vision that a comprehensive program of vaccination, screening, and treatment should be made accessible to all girls and women in the world. The primary purpose of these guidelines is to provide information on scientific evidence on the different modalities and approaches of cervical cancer prevention programs, for high resource and low resource settings. The secondary purpose is to provide an overview of the current situation of cervical cancer control and prevention in various Asian Oceania countries: their views of an ideal program, identified obstacles, and suggestions to overcome them are discussed.

Cost-effectiveness of different human papillomavirus vaccines in Singapore

Background

Human papillomavirus (HPV) vaccines are widely available and there have been studies exploring their potential clinical impact and cost-effectiveness. However, few studies have compared the cost-effectiveness among the 2 main vaccines available - a bivalent vaccine against HPV 16/18, and a quadrivalent vaccine against 6/11/16/18. We explore the cost-effectiveness of these two HPV vaccines in tropical Singapore.

Methods

We developed a Markov state-transition model to represent the natural history of cervical cancer to predict HPV infection, cancer incidence, mortality, and costs. Cytologic screening and treatment of different outcomes of HPV infection were incorporated. Vaccination was provided to a cohort of 12-year old females in Singapore, followed up until death. Based on available vaccines on the market, the bivalent vaccine had increased effectiveness against a wider range of HPV types, while the quadrivalent vaccine had effectiveness against genital warts. Incremental cost-effectiveness ratios (ICER) compared vaccination to no-vaccination, and between the two vaccines. Sensitivity analyses explored differences in vaccine effectiveness and uptake, and other key input parameters.

Results

For the no vaccination scenario, 229 cervical cancer cases occurred over the cohort's lifetime. The total discounted cost per individual due to HPV infection was SGD$275 with 28.54 discounted life-years. With 100% vaccine coverage, the quadrivalent vaccine reduced cancers by 176, and had an ICER of SGD$12,866 per life-year saved. For the bivalent vaccine, 197 cancers were prevented with an ICER of $12,827 per life-year saved. Comparing the bivalent to the quadrivalent vaccine, the ICER was $12,488 per life-year saved. However, the cost per QALY saved for the quadrivalent vaccine compared to no vaccine was $9,071, while it was $10,392 for the bivalent vaccine, with the quadrivalent vaccine dominating the bivalent vaccine due to the additional QALY effect from reduction in genital warts. The overall outcomes were most sensitive to vaccine cost and coverage.

Conclusion

HPV vaccination is a cost-effective strategy, and should be considered a possible strategy to reduce the impact of HPV infection.

Prevalence of human papillomavirus genotypes in northern Taiwanese women

The prevalence of Human Papillomavirus (HPV) in the general population of northern Taiwan is described. A total of 343 consecutive cervical swabs from women visiting the medical center for routine gynecologic care were included. Cervical cell cytology was examined by the Papanicolaou (Pap) test, and a PCR-based hybridization gene chip analysis was used to identify HPV genotypes. The HPV prevalence in the overall population was 32.4%. When divided into two groups according to cytology, 20.9% of women with normal cytology were HPV positive while 75.3% of women with abnormal cytology were HPV positive. Among positive samples, 68.5% were single type infections while 31.5% harbored multiple HPV types. A total of 32 types of HPV were identified; the leading five were HPV16 (5.8%), HPV58 (5.3%), HPV53 (4.1%), HPV52 (3.8%), and HPV18 (2.3%). Our results constitute baseline data and may provide important implications for future prophylactic programs. The relatively high prevalence of HPV 58, 53, and 52 among northern Taiwanese women has important implications for vaccine development.

Type-specific human papillomavirus oncogene messenger RNA levels correlate with the severity of cervical neoplasia

This study aimed to evaluate whether quantitation of high-risk human papillomavirus (HR-HPV) E6 messenger RNA (mRNA) can be a potential biomarker for detecting the severity of cervical lesions. HPV genotyping was performed using a modified MY11/GP6+ PCR for HPV DNA amplification, followed by HPV genotype-specific hybridization with on a gene chip. E6 type-specific PCR was used to validate multiple infections. Quantitative real-time reverse transcriptase (QRT-PCR) and real-time PCR used to measure mRNA levels and DNA viral loads of 6 HPV oncogenic types (HPV 16, 18, 31, 33, 52 and 58) in 720 liquid-based cytology samples. The HPV DNA and RNA measurements were correlated with cervical lesions diagnosed by histopathologic examination. mRNA transcripts in the 6 types HPV DNA-positive cases was lower in normal women and <CIN 1 (23%), women with CIN 1 (54%), CIN2+ (77%) and CIN3+ (80%) (p < 0.001). Geometric mean mRNA levels ranged from 24.5 (copies per 50 ng total RNA) in normal women and <CIN 1 to 210.8 in those with CIN 1, 629.0 in CIN2+ and 699.0 in CIN3+ (p < 0.0001). Trends of increasing viral mRNA with severity of histopathologic diagnosis were significant for HPV 16, 18, 52 and 58 transcripts but not for HPV 31 and 33 transcripts. However, geometric mean DNA viral loads of HPV 16, 18, 52 and 58 DNA did not significantly increase with the severity of cervical dysplasia. Therefore, quantitative HPV E6 mRNA levels of high-risk HPV types are potentially useful biomarkers for distinguishing among HPV infections, cervical precancerous lesions and cancer.

Cost-effectiveness of human papillomavirus vaccination for prevention of cervical cancer in Taiwan

BACKGROUND

Human papillomavirus (HPV) infection has been shown to be a major risk factor for cervical cancer. Vaccines against HPV-16 and HPV-18 are highly effective in preventing type-specific HPV infections and related cervical lesions. There is, however, limited data available describing the health and economic impacts of HPV vaccination in Taiwan. The objective of this study was to assess the cost-effectiveness of prophylactic HPV vaccination for the prevention of cervical cancer in Taiwan.

METHODS

We developed a Markov model to compare the health and economic outcomes of vaccinating preadolescent girls (at the age of 12 years) for the prevention of cervical cancer with current practice, including cervical cytological screening. Data were synthesized from published papers or reports, and whenever possible, those specific to Taiwan were used. Sensitivity analyses were performed to account for important uncertainties and different vaccination scenarios.

RESULTS

Under the assumption that the HPV vaccine could provide lifelong protection, the massive vaccination among preadolescent girls in Taiwan would lead to reduction in 73.3% of the total incident cervical cancer cases and would result in a life expectancy gain of 4.9 days or 8.7 quality-adjusted life days at a cost of US$324 as compared to the current practice. The incremental cost-effectiveness ratio (ICER) was US$23,939 per life year gained or US$13,674 per quality-adjusted life year (QALY) gained given the discount rate of 3%. Sensitivity analyses showed that this ICER would remain below US$30,000 per QALY under most conditions, even when vaccine efficacy was suboptimal or when vaccine-induced immunity required booster shots every 13 years.

CONCLUSIONS

Although gains in life expectancy may be modest at the individual level, the results indicate that prophylactic HPV vaccination of preadolescent girls in Taiwan would result in substantial population benefits with a favorable cost-effectiveness ratio. Nevertheless, we should not overlook the urgency to improve the compliance rate of cervical screening, particularly for older individuals.

Evaluation of a newly developed GenoArray human papillomavirus (HPV) genotyping assay and comparison with the Roche Linear Array HPV genotyping assay

Persistent infection with high-risk types of human papillomavirus (HPV) is a necessary step in the development of cervical cancer. The incorporation of HPV detection into cervical screening programs may improve the ability to identify women at risk of cervical cancer. We recently evaluated the performance characteristics of a newly developed HPV detection assay, the GenoArray (GA) genotyping assay, for the detection of HPV infections by comparing it with the commercial Roche Linear Array (LA) HPV genotyping assay. The GA assay has an analytical sensitivity for the detection of HPV types 16 (HPV-16) and HPV-18 of as few as 10 to 50 copies, and its reproducibility is adequate. The GA and LA assays showed no significant difference in the rates of detection of genotypes detected by both HPV genotyping assays and oncogenic genotypes, and the interassay agreement was excellent. The GA and LA assays revealed either concordant or compatible genotyping results for 97.5% of the samples and discordant results for only eight (2.5%) samples. Compatible results were also observed for the detection of single or multiple HPV infections and the detection of most of the genotypes. The GA assay also demonstrated good clinical performance characteristics when the comparisons were carried out with clinical subgroups of samples from patients with normal cytologies, low-grade or high-grade squamous intraepithelial lesions, and cancers. Therefore, the GA assay appears to be highly sensitive and specific for the genotyping of HPV. It has the advantage that it specifically detects HPV-52, which overcomes a limitation of the LA assay, and hence, it has potential value for use for genotyping, especially in regions where HPV-52 has a high prevalence.