Effect of human papillomavirus vaccination on cervical cancer screening in Alberta

The Clinical Effectiveness of Single-Dose Human Papillomavirus Vaccination

The human papillomavirus (HPV) vaccine was initially approved for a three-dose regimen. Due to resource limitations, budget constraints, low acceptance, and poor adherence, global vaccination coverage is only 15%. A single-dose regimen could simplify logistics, reduce costs, and improve accessibility. However, its clinical effectiveness remains debatable. This review systematically searched PubMed, Embase, and Cochrane Library, including 42 clinical studies, to assess the effectiveness of a single-dose HPV vaccination for preventing HPV infections, cervical abnormalities, and genital warts. We summarized the effectiveness of bivalent, quadrivalent, and nonavalent vaccines across different age groups and buffer periods, and analyzed the factors contributing to the inconsistency of results. The review also provides insights into designing robust future research to inform single-dose HPV vaccination policies and guidelines, highlighting the need for further research to refine vaccination strategies.

Social factors and age play a significant role in cervical cancer and advanced-stage disease among Danish women

BACKGROUND

For cervical cancer (CC), the implementation of preventive strategies has the potential to make cervical cancer occurrence and death largely avoidable. To better understand the factors possibly responsible for cervical cancer, we aimed to examine possible differences in age and social parameters as well as screening status between women with low- or high-stage cervical cancer and matched controls.

METHODS

Through the Danish Cancer Registry (DCR), women diagnosed with cervical cancer in Denmark between 1987 and 2016 were included. These were age- and residence-matched in a 1:5 ratio with controls from the general female population. The study population was sub grouped into a low-stage subpopulation with women with early-stage cervical cancer and matched controls and a high-stage subpopulation with women with late-stage cervical cancer and matched controls. Age and social parameters were compared within the subpopulations as well as between low- and high-stage cases. For part of the study population, screening attendance was examined to compare differences in adherence.

RESULTS

Overall, we found that the risk of cervical cancer is significantly increased in socially disadvantaged women and not least non-attenders in screening. Interestingly, the high-stage subpopulation was significantly older than the low-stage subpopulation (p < 0.001), and when examining the impact of age further, we found that for cervical cancer cases, the risk of having low-stage disease decreases significantly with increasing age, whereas the risk of having high-stage disease increases significantly with increasing age. In the screening cohort, significantly less cases than controls were attenders in screening with the most pronounced differences seen in the old subpopulation (women aged 50-64 years) and in the high-stage subpopulation (p-values all < 0.001). Interestingly, when examining the risk of CC for attenders and non-attenders, we demonstrated that many social parameters continue to influence the risk of cervical cancer, even in women attending screening.

CONCLUSIONS

Older women, socially disadvantaged women, and non-attenders in screening are particularly vulnerable in terms of developing cervical cancer, especially high-stage disease. Therefore, improvements in the participating rate in screening as well as a revision of the current screening guidelines are needed.

The Consensus Project: Participation in cervical cancer screening by the first cohorts of girls offered HPV vaccination at age 15-16 years in Italy

OBJECTIVE

To evaluate the association between human papillomavirus vaccination status and participation in cervical cancer screening (at age 25) by the first cohorts of girls who were offered vaccination at the age of 15 to 16 years in Italy.

METHODS

Women born in 1993, 1994 and 1995 were invited to participate in cervical cancer screening between 2018 and 2020. We report participation in screening by vaccination status in three large areas, Florence province, Piedmont region and Savona province, where the Consensus Project was carried out. The relative risk of participation among vaccinated (≥2 doses) and unvaccinated women was estimated. Odds ratios (OR) of participation by vaccination status were estimated by logistic regression, adjusted by birthplace and birth cohort.

RESULTS

Overall, 34,993 women were invited for screening: 13,006 (37.2%) participated and 10,062 of these agreed to participate in the Consensus intervention study. Among the invited women and screening participants, vaccinated women were 51.0% and 60.6%, respectively. Comparing vaccinated and unvaccinated women, the adjusted OR of screening participation was 1.80 (95% confidence interval (CI): 1.72-1.89), 2.17 (95% CI: 1.94-2.42), 1.59 (95% CI: 1.50-1.68) and 1.15 (95% CI: 0.86-1.54) for overall, Florence, Piedmont and Savona, respectively. About 33% of the invited women were unvaccinated and did not participate in screening: 25.8%, 59.5% and 64.2% of women born in Italy, in high migration pressure countries and in advanced development countries, respectively.

CONCLUSIONS

Screening participation was higher among vaccinated than unvaccinated women. Active policies are needed to reduce inequalities, targeting the unscreened and unvaccinated population, particularly non-native women, to accelerate cervical cancer elimination in Italy.

A single dose of quadrivalent HPV vaccine is highly effective against HPV genotypes 16 and 18 detection in young pregnant women eight years following vaccination: an retrospective cohort study in Fiji

Background

In 2008/9, Fiji vaccinated >30,000 girls aged 9-12 years with the quadrivalent human papillomavirus (4vHPV) vaccine coverage for at least one dose was >60% (one dose only was 14%, two dose only was 13%, three doses was 35%). We calculated vaccine effectiveness (VE) of one, two and three doses of 4vHPV against oncogenic HPV genotypes 16/18, eight years following vaccination.

Methods

A retrospective cohort study was undertaken (2015-2019) in pregnant women ≤23 years old, eligible to receive 4vHPV in 2008/9, with confirmed vaccination status. The study was restricted to pregnant women due to the cultural sensitivity of asking about sexual behavior in Fiji. For each participant a clinician collected a questionnaire, vaginal swab and genital warts examination, a median eight (range 6-11) years post vaccination. HPV DNA was detected by molecular methods. Adjusted VE (aVE) against the detection of vaccine HPV genotypes (16/18), the comparison group of non-vaccine genotypes (31/33/35/39/45/51/52/56/58/59/66/68), and genital warts were calculated. Covariates included in the adjusted model were: age, ethnicity and smoking, according to univariate association with any HPV detection.

Findings

Among 822 participants the prevalence of HPV 16/18 in the unvaccinated, one, two and three-dose groups were 13.3% (50/376), 2.5% (4/158), 0% (0/99) and 1.6% (3/189), respectively; and for the non-vaccine high-risk genotypes, the detection rate was similar across dosage groups (33.2%-40.4%, p = 0.321). The aVE against HPV 16/18 for one, two and three doses were 81% (95% CI; 48-93%), 100% (95% CI; 100-100%), and 89% (95% CI; 64-96%), respectively. Prevalence of HPV 16/18 was lower among women with longer time since vaccination.

Interpretations

A single dose 4vHPV vaccine is highly effective against HPV genotypes 16 and 18 eight years following vaccination. Our results provide the longest duration of protection for reduced dose 4vHPV schedule in a low- or middle-income country in the Western Pacific region.

Funding

This study was supported by the Bill & Melinda Gates Foundation and the Department of Foreign Affairs and Trade of the Australian Government and Fiji Health Sector Support Program (FHSSP). FHSSP is implemented by Abt JTA on behalf of the Australian Government.

Real-world impact and effectiveness of the quadrivalent HPV vaccine: an updated systematic literature review

INTRODUCTION

Human papillomavirus (HPV) infection, which poses significant disease burden, is decreasing following implementation of vaccination programs. Synthesized evidence on HPV vaccine real-world benefit was published in 2016. However, long-term impact of vaccination, and how vaccination programs influence infection rates and disease outcomes, requires further examination.

AREAS COVERED

We systematically reviewed observational studies on HPV vaccination within MEDLINE, EMBASE, and Google Scholar from 2016 to 2020, involving 14 years of follow-up data. We identified 138 peer-reviewed publications reporting HPV vaccine impact or effectiveness. Outcomes of interest included rates of infection at different anatomical sites and incidence of several HPV-related disease endpoints.

EXPERT OPINION

The expansion of HPV vaccination programs worldwide has led to a reduction in genital infection and significant decreases in incidence of HPV-related disease outcomes. Therefore, the WHO has set goals for the elimination of cervical cancer as a public health concern. To track progress toward this requires an understanding of the effectiveness of different vaccination initiatives. However, the impact on males, and potential benefit of gender-neutral vaccination programs have not been fully explored. To present an accurate commentary on the current outlook of vaccination and to help shape policy therefore requires a systematic review of available data.

Human papillomavirus vaccine effectiveness by number of doses: Updated systematic review of data from national immunization programs

BACKGROUND

Human papillomavirus (HPV) vaccines were first licensed as a three-dose series. Two doses are now widely recommended in some age groups; there are data suggesting high efficacy with one dose. We updated a systematic literature review of HPV vaccine effectiveness by number of doses in observational studies.

METHODS

We searched Medline and Embase databases from January 1, 2007, through September 29, 2021. Data were extracted and summarized in a narrative synthesis. We also conducted quality assessments for bias due to selection, information, and confounding.

RESULTS

Overall, 35 studies were included; all except one were conducted within the context of a recommended three-dose schedule. Evaluations were in countries that used bivalent HPV vaccine (seven), quadrivalent HPV vaccine (27) or both (one). Nine evaluated effectiveness against HPV infection, ten anogenital warts, and 16 cervical abnormalities. All studies were judged to have moderate or serious risk of bias. The biases rated as serious would likely result in lower effectiveness with fewer doses. Investigators attempted to control for or stratify by potentially important variables, such as age at vaccination. Eight studies evaluated impact of buffer periods (lag time) for case counting and 10 evaluated different intervals between doses for two-dose vaccine recipients. Studies that stratified by vaccination age found higher effectiveness with younger age at vaccination, although differences were not all formally tested. Most studies found highest estimates of effectiveness with three doses; significant effectiveness was found among 28/29 studies that evaluated three doses, 19/29 that evaluated two doses, and 18/30 that evaluated one dose. Some studies that adjusted or stratified analyses by age at vaccination found similar effectiveness with three, two and one doses.

CONCLUSION

Observational studies of HPV vaccine effectiveness have many biases. Studies examining persons vaccinated prior to sexual activity and using methods to reduce sources of bias are needed for valid effectiveness estimates.

Real-world impact and effectiveness assessment of the quadrivalent HPV vaccine: a systematic review of study designs and data sources

INTRODUCTION

Vaccine effectiveness and impact studies are typically observational, generating evidence after vaccine launch in a real-world setting. For human papillomavirus (HPV) vaccination studies, the variety of data sources and methods used is pronounced. Careful selection of study design, data capture and analytical methods can mitigate potential bias in such studies.

AREAS COVERED

We systematically reviewed the different study designs, methods, and data sources in published evidence (1/2007-3/2020), which assessed the quadrivalent HPV vaccine effectiveness and impact on cervical/cervicovaginal, anal, and oral HPV infections, anogenital warts, lesions in anus, cervix, oropharynx, penis, vagina or vulva, and recurrent respiratory papillomatosis.

EXPERT OPINION

The rapid growth in access to real-world data allows global monitoring of effects of different public health interventions, including HPV vaccination programs. But the use of data which are not collected or organized to support research also underscore a need to develop robust methodology that provides insight of vaccine effects and consequences of different health policy decisions. To achieve the WHO elimination goal, we foresee a growing need to evaluate HPV vaccination programs globally. A critical appraisal summary of methodology used will provide timely guidance to researchers who want to initiate research activities in various settings.

Human papillomavirus vaccination history and diagnosis of cervical intraepithelial neoplasia grade ≥2 severe lesions among a cohort of women who underwent colposcopy in Kaiser Permanente Southern California

BACKGROUND

The risk of a high-grade lesion in women undergoing colposcopy following an abnormal screening result may be different by human papillomavirus vaccination status, because women who are vaccinated are presumably less likely to harbor human papillomavirus types 16 and 18.

OBJECTIVE

This study aimed to evaluate whether the risk of high-grade cervical lesion diagnosed through colposcopy is lower in women with human papillomavirus vaccination than in women without vaccination referred to colposcopy based on equal abnormal screening findings.

STUDY DESIGN

Kaiser Permanente Orange County female patients between ages 21 and 38 years were included following an abnormal screening if they had ≥1 colposcopies between July 2017 and August 2018 and had at least 1 pathology diagnosis from the colposcopy visits. Data on demographic characteristics, clinical and sexual histories, and human papillomavirus vaccination were collected using a colposcopy registry smart form and from electronic medical records. Human papillomavirus genotyping was performed for tissues from confirmed cervical intraepithelial neoplasm grade 2+ diagnoses. A multilevel generalized linear model with a logic function was used to evaluate the association between human papillomavirus vaccination history and the outcome of a cervical intraepithelial neoplasm grade 2+ diagnosis and for human papillomavirus type 16- or 18-positive cervical intraepithelial neoplasm grade 2+ as an alternative outcome, adjusting for screening results and potential confounders.

RESULTS

Of 730 women included in the study, 170 had a histologic diagnosis of cervical intraepithelial neoplasm grade 2+ (23.2%). Moreover, 68 cases (40.0%) were histologically human papillomavirus type 16 and/or 18 positive. Of the 730 women, 311 (43%) were vaccinated for the human papillomavirus before colposcopy. Most women (206 [66.2%]) with human papillomavirus vaccination received the vaccine between the ages 18 and 26 years. A history of human papillomavirus vaccination overall, before sexual debut, before the age of 18 years, or with complete dosing was not associated with lower odds of a cervical intraepithelial neoplasm grade 2+ diagnosis (odds ratio, 1.07 [95% confidence interval, 0.70-1.64]; odds ratio, 1.11 [95% confidence interval, 0.55-2.24]; odds ratio, 0.96 [95% confidence interval, 0.49-1.91]; and odds ratio, 0.84 [95% confidence interval, 0.53-1.35], respectively, in reference to no vaccination). Human papillomavirus vaccination history was not significantly associated with the odds of a human papillomavirus type 16- or 18-positive cervical intraepithelial neoplasm grade 2+ diagnosis (P=.45). Notably, 8 cases (4.8% of all cervical intraepithelial neoplasm grade 2+ cases) showed a human papillomavirus type 16 on a cervical intraepithelial neoplasm grade 2+ histologic polymerase chain reaction analysis despite reported or documented human papillomavirus vaccination before sexual debut, including 2 cases who started vaccination before the age of 13 years.

CONCLUSION

Our study did not support modifying the colposcopy management guidelines for abnormal screening results for women with human papillomavirus vaccination, especially those vaccinated in the catch-up age range. Our findings on the 8 cases of human papillomavirus 16-positive cervical intraepithelial neoplasm grade 2+ vaccination before sexual debut suggested that lowering the recommended age for human papillomavirus vaccination may have additional benefits for preventing human papillomavirus infection that could occur early in life in some women.

Catch-up HPV Vaccination and Subsequent Uptake of Papanicolaou Testing in A State-mandated Health System

The objective of this study was to evaluate the association between human papillomavirus (HPV) vaccination and uptake of initial Papanicolaou (Pap) testing in Israel among women not previously vaccinated through the national immunization program. In this retrospective cohort we used health provider records of vaccinations and cancer screening attendance among female members of a state-mandated health provider in Israel (Maccabi Healthcare Services, MHS). All eligible female members (N = 20,904) immunized with at least one dose of HPV vaccine from the date of its introduction in Israel (June 2007) until December 31, 2018 were individually matched with nonvaccinated MHS members on one to one ratio by year of birth, residential area socioeconomic level, and district of residence. Data on the uptake of Pap smears until December 2018 were extracted from MHS central datasets, and the number of Pap smears for each woman during the study period was counted. During the observed follow-up period (mean, 6.6 years; interquartile range, 3.9-8.7 year), the cumulative uptake rate of Pap testing in vaccinated women (26.8%) was significantly (P < 0.001) greater than among unvaccinated (22.4%) women. In a multivariable model, HPV vaccination was associated with an HR of 1.34 [95% confidence interval (CI), 1.29-1.41] to perform Pap testing. Our findings suggest that uptake of catch-up HPV vaccine was positively correlated to increased uptake of Pap testing. PREVENTION RELEVANCE: We found that catch-up HPV vaccination was associated with increased attention to long-term cervical screening attendance. Whereas, those who are not vaccinated and unprotected from HPV, are more likely to abstain from secondary prevention screening tests too and further increase their cervical cancer risk.

Epidemiology of Virus Infection and Human Cancer

Seven viruses including the Epstein-Barr virus (EBV), hepatitis B virus (HBV), hepatitis C virus (HCV), Kaposi's sarcoma herpes virus (KSHV), human immunodeficiency virus, type-1 (HIV-1), human T cell lymphotrophic virus, type-1 (HTLV-1), and human papillomavirus (HPV) have been classified as Group 1 human carcinogens by the International Agency for Research on Cancer (IARC). The conclusions are based on the findings of epidemiological and mechanistic studies. EBV, HPV, HTLV-1, and KSHV are direct carcinogens; HBV and HCV are indirect carcinogens through chronic inflammation; and HIV-1 is an indirect carcinogen through immune suppression. Some viruses may cause more than one cancer, while some cancers may be caused by more than one virus. However, only a proportion of persons infected by these oncogenic viruses will develop specific cancers. A series of studies have been carried out to assess the viral, host, and environmental cofactors of EBV-associated nasopharyngeal carcinoma, HBV/HCV-associated hepatocellular carcinoma, and HPV-associated cervical carcinoma. Persistent infection, high viral load, and viral genotype are important risk predictors of these virus-caused cancers. Risk calculators incorporating host and viral risk predictors have been developed for the prediction of long-term risk of hepatocellular carcinoma, nasopharyngeal carcinoma and cervical cancer. These risk calculators are useful for the triage and clinical management of infected patients. Both clinical trials and national programs of immunization, antiviral therapy and screening have demonstrated a significant reduction in the incidence of cancers caused by HBV, HCV, and HPV. Future research on gene-gene and gene-environment interactions of oncogenic viruses and the human host using large-scale longitudinal studies with serial measurements of biosignatures are in urgent need.

Human papillomavirus vaccine effectiveness within a cervical cancer screening programme: cohort study

OBJECTIVE

To assess the effectiveness of an HPV vaccination programme in reducing the risk of cervical abnormalities identified at subsequent screening.

DESIGN

Retrospective cohort study using administrative health data.

SETTING

General population of Ferrara Province, Italy.

POPULATION

Female residents born in 1986-1993 and participating in the organized cervical screening programme in 2011-2018, who were eligible for HPV vaccination in catch-up cohorts.

METHODS

Logistic regression to evaluate the potential association between abnormal cervical cytology and one, two, three or at least one dose of HPV vaccine.

MAIN OUTCOME MEASURES

Cervical abnormalities, as predicted by low-grade or high-grade cytology, by number of vaccine doses, stratified by age.

RESULTS

The sample consisted of 7785 women (mean age 27.5 years, SD 2.3). Overall, 391 (5.0%) were vaccinated with ≥1 dose and 893 (11.5%) had abnormal cytology. Women receiving at least one vaccine dose were significantly less likely to have an abnormal cytology (adjusted odds ratio 0.52; 95% confidence interval 0.34-0.79). Similar results were observed for women receiving a single dose, for both bivalent and quadrivalent vaccines, and applying buffer periods (excluding cytological outcomes within 1 month, 6 months and 1 year of the first dose).

CONCLUSIONS

In the context of an organised cervical screening programme in Italy, catch-up HPV vaccination almost halved the risk of cytological abnormalities.

TWEETABLE ABSTRACT

Among Ferrara women, vaccination against human papillomavirus halved the risk of screening cervical abnormalities.

Cervical Intraepithelial Neoplasia Rates in British Columbia Women: A Population-Level Data Linkage Evaluation of the School-Based HPV Immunization Program

BACKGROUND

To understand real-world human papillomavirus (HPV) vaccine impact, continuous evaluation using population-based data is critical. We evaluated the early impact of the school-based HPV immunization program on cervical dysplasia in women in British Columbia, Canada.

METHODS

Data linkage was performed using records from provincial cervical screening and immunization registries. Precancerous outcomes were compared between unvaccinated and HPV-vaccinated women born 1994-2005. Incidence rate, relative rate (RR), and vaccine effectiveness (VE), using unadjusted and adjusted Poisson regression of cytology (HSIL) and histopathology (CIN2, CIN3, and CIN2+) outcomes, were compared across vaccination status groups.

RESULTS

Women who received a complete series of vaccine on schedule between age 9 and 14 years had an adjusted RR = 0.42 (95% confidence interval [CI], 0.31-0.57) for CIN2+ over 7 years of follow-up compared to unvaccinated women, resulting in a VE of 57.9% (95% CI, 43.2%-69.0%). Adjusted RR for HSIL was 0.53 (95% CI, .43-.64), resulting in a VE of 47.1% (95% CI, 35.6%-56.7%).

CONCLUSION

Women vaccinated against HPV have a lower incidence of cervical dysplasia compared to unvaccinated women. Immunization between 9 and 14 years of age should be encouraged. Continued program evaluation is important for measuring long-term population impact.

Effectiveness of 1, 2, and 3 Doses of Human Papillomavirus Vaccine Against High-Grade Cervical Lesions Positive for Human Papillomavirus 16 or 18

Before 2016, human papillomavirus (HPV) vaccination was recommended on a 3-dose schedule. However, many vaccine-eligible US females received fewer than 3 doses, which provided an opportunity to evaluate the real-world vaccine effectiveness (VE) of 1, 2, and 3 doses. We analyzed data on cervical intraepithelial neoplasia (CIN) grades 2-3 and adenocarcinoma in situ (designated CIN2+) from the HPV Vaccine Impact Monitoring Project (HPV-IMPACT; 2008-2014). Archived tissue from CIN2+ lesions was tested for 37 types of HPV. Women were classified by number of doses received ≥24 months before CIN2+ detection. Using a test-negative design, VE was estimated as 1 minus the adjusted odds ratio from a logistic regression model that compared vaccination history for women whose lesions tested positive for HPV-16/18 (vaccine-type cases) with that for women who had all other CIN2+ lesions (controls). Among 3,300 women with available data on CIN2+, typing results, and vaccine history, 1,561 (47%) were HPV-16/18-positive, 136 (4%) received 1 dose of HPV vaccine, 108 (3%) received 2 doses, and 325 (10%) received 3 doses. Adjusted odds ratios for vaccination with 1, 2, and 3 doses were 0.53 (95% confidence interval (CI): 0.37, 0.76; VE = 47%), 0.45 (95% CI: 0.30, 0.69; VE = 55%), and 0.26 (95% CI: 0.20, 0.35; VE = 74%), respectively. We found significant VE against vaccine-type CIN2+ after 3 doses of HPV vaccine and lower but significant VE with 1 or 2 doses.

Non-Adherence To Childhood HPV Vaccination Is Associated With Non-Participation In Cervical Cancer Screening - A Nationwide Danish Register-Based Cohort Study

Background

The combination of organized cervical cancer screening and childhood HPV vaccination programs has the potential to eliminate cervical cancer in the future. However, only women participating in both programs gain the full protection, and combined non-attenders remain at high risk of developing cervical cancer. Our aim was to analyze the association between non-adherence to HPV vaccination and non-participation in cervical cancer screening for the total population and stratified by native background and parental education.

Participants

Women born in 1993 eligible for both childhood HPV vaccination and first cervical cancer screening.

Analysis

Logistic regression models were used to estimate the odds ratio (OR) of non-participation in cervical cancer screening with 95% confidence intervals (CI). Stratified and adjusted logistic regression models were used along with the Wald test in order to test for interaction.

Results

24,828 women were included in the study. Among vaccinated women, 61.4% participated in cervical cancer screening; only 39.0% of unvaccinated women participated in cervical cancer screening. Unvaccinated and unscreened women were often non-native and had the lowest socio-economic status, whereas vaccinated and screened women were often native and had the highest socio-economic status. The adjusted OR for non-participation in cervical cancer screening was 2.07 [95% CI: 1.88–2.28] for unvaccinated compared to vaccinated women. After stratifying by country of origin, unvaccinated natives had the highest adjusted OR of not participating in cervical cancer screening compared to non-native women from both western and non-western countries (adjusted ORs of 2.2 [95% CI: 2.0–2.4], 1.3 [95% CI: 0.6–2.8], and 1.5 [95% CI: 1.1–2.0], respectively) (Wald test p=0.019).

Conclusion

Among natives, non-adherence to HPV vaccination and non-participation in screening seem to be signs of generally poor health-preventive behavior, whereas among non-natives from non-western countries, non-attendance in HPV vaccination and cervical cancer screening seem to be influenced by unrelated factors. Therefore, a differentiated and culturally sensitive approach is needed to enhance overall cervical cancer preventive behavior across different nativities.

Cancer screening in the United States, 2019: A review of current American Cancer Society guidelines and current issues in cancer screening

Each year, the American Cancer Society publishes a summary of its guidelines for early cancer detection, data and trends in cancer screening rates, and select issues related to cancer screening. In this issue of the journal, the current American Cancer Society cancer screening guidelines are summarized, and the most current data from the National Health Interview Survey are provided on the utilization of cancer screening for men and women and on the adherence of men and women to multiple recommended screening tests.

Post-hoc analysis from phase III trials of human papillomavirus vaccines: considerations on impact on non-vaccine types

BACKGROUND

Substantial heterogeneity has been reported in efficacy against high-grade cervical intraepithelial neoplasia (CIN) irrespective of HPV type in phase III results for bivalent and quadrivalent human papillomavirus virus (HPV) vaccines (AS04-HPV and qHPV). Real-world data recently confirmed a very high overall impact of AS04-HPV, supporting the validity of the observed heterogeneity. To explore the reasons for heterogeneous efficacy, we assessed vaccine impact on high-grade lesions not caused by vaccine types.

RESEARCH METHODS

We extracted case counts of CIN lesions containing (1) at least one vaccine HPV type, (2) at least one vaccine HPV type and a high-risk non-vaccine type (co-infections) and (3) no vaccine types (non-vaccine or no high-risk HPV types). Based on these, Phase III cross-protective efficacies were estimated with exclusion (3) and with inclusion (2 and 3) of co-infections.

RESULTS

Cross-protective efficacy of AS04-HPV against CIN3 lesions ranges from 81.3% (95%CI: 34.7;96.5) (excluding co-infections) to 88.5% (95%CI:62.4;97.8) (including co-infections). For qHPV the efficacy ranges from -58.7% (95%CI: -180.5;8.5) (excluding co-infections) to 13.1% (95%CI: -39.0;45.9) (including co-infections).

CONCLUSIONS

Heterogenous overall efficacy against CIN3 between AS04-HPV and qHPV is driven by differential efficacy against lesions that do not contain vaccine types, which may be related to the impact of different adjuvants on the immune response.

Prevalence of epithelial abnormalities and high-risk human papilloma virus in cervicovaginal Pap smears of population subgroups as a guide toward evidence-based best practice

BACKGROUND

The 2012 American Society for Colposcopy and Cervical Pathology Consensus Guidelines provide information for managing abnormal cervical cancer screening tests and cancer precursors. According to these guidelines for Pap smear diagnosis of Atypical squamous cells of undetermined significance, reflex high risk (HR) human papilloma virus (HPV) genotyping is required among women 21 years of age or older. Whereas, in women of 30 to 65 years of age, HR-HPV can be ordered by the clinicians as part of co-testing with any diagnosis and every 5 years with a negative Cervico-Vaginal Pap test (CVPT).

METHODS

A retrospective review of the CoPath database of the Pathology Department at the University of Florida, College of Medicine Jacksonville, FL, was performed to identify North Florida (NF) women who underwent CVPT and HR-HPV testing between 2006 and 2014. The women were stratified by race and age, respectively.

RESULTS

The study included 19,933 CVPTs. Significant differences in the outcomes' distributions were found among age and race groups, respectively. Highest prevalence of HPV positivity was found in African American women, and in 14- to 20-year-old women, respectively. Twenty- to 30-year-old women had the highest percentage (59%) of epithelial abnormality. The most common HR-HPV genotypic distribution was other HR-HPV.

CONCLUSIONS

This study underscores the importance of using both HR-HPV and CVPT for screening for cervical cancer, and confirms the need for special focus on managing high-risk populations subgroups, such as African American women, and women of ages 14 to 20 years especially in high-risk populations.

Human Papillomavirus Infection and Cervical Cancer in HIV+ Women

Human papillomavirus (HPV) is the first identified necessary cause of human cancers and is associated with nearly 100% of all cervical cancers. Compared to the general female populations, HIV+ women have higher prevalence and incidence of cervical HPV infections, higher risks of persistent HPV infections and subsequent cervical intraepithelial lesions, and a higher incidence of cervical cancer. Although the wide use of combined antiretroviral therapy (cART) has improved the immune function and the longevity of HIV+ women, the incidence of cervical cancer in HIV+ women has not declined. For HIV+ women who follow routine cervical cancer screenings, their incidence of cervical cancer is comparable to that in HIV-negative women. Thus, adherence to the recommended cervical cancer screening is still critical for HIV+ women to prevent cervical cancer. Prophylactic HPV vaccines may also benefit HIV+ women, but prospective studies are needed to determine the effectiveness of HPV vaccination on reducing cervical cancer incidence in HIV+ women.

Opportunistic HPV vaccination at age 16-23 and cervical screening attendance in Sweden: a national register-based cohort study

OBJECTIVES

To investigate whether cervical screening attendance differs between human papillomavirus (HPV)-vaccinated and unvaccinated women and to investigate potential underlying socioeconomic factors.

DESIGN

Prospective cohort using registry linkage of vaccinations, screening invitations, screening attendance and socioeconomic covariates.

SETTING

Swedish national HPV vaccination and cervical screening programmes.

PARTICIPANTS

All Swedish women born between 1988 and 1991 and invited to screening (n=261 434).

OUTCOME MEASURES

All participants were followed for up to 3 years. Screening attendance was compared between HPV-vaccinated and unvaccinated women. HR and 95% CI were estimated using Cox regression.

RESULTS

Vaccination age averaged 18.1 years and the coverage for≥1 dose was 13.5%. In HPV-vaccinated women (n=35 460), screening attendance was higher than in unvaccinated women (n=225 974) (74%vs69%, p<0.001). The crude HR of attendance in HPV-vaccinated women was 1.32 (95% CI 1.30 to 1.34). A positive association remained after adjustment for education, income and migration history (HR=1.10, 95% CI 1.09 to 1.12).

CONCLUSION

HPV-vaccinated women were more likely to attend screening than unvaccinated women. Yet, the question needs to be reassessed in routinely vaccinated cohorts, since the vaccinated women included here represent a selected group and may be prone to more health-conscious habits.

Effectiveness of catch-up human papillomavirus vaccination on incident cervical neoplasia in a US health-care setting: a population-based case-control study

BACKGROUND

The population effectiveness of human papillomavirus (HPV) catch-up vaccination, defined in the USA as first vaccination at ages 13-26 years, has not been studied extensively. We aimed to assess the risk of cervical intraepithelial neoplasia (CIN) 2, CIN3, adenocarcinoma in situ, or cancer (CIN2+ and CIN3+) by prior HPV vaccination status, age at first dose, and number of doses in women participating in a screening programme within a large integrated health-care system.

METHODS

We performed a nested case-control study of women enrolled in Kaiser Permanente Northern California (an integrated health-care delivery system in California, USA). Cases were women with CIN2+ or CIN3+ confirmed by histology between Jan 1, 1995, and June 30, 2014, and incidence density-selected controls were age-matched women without CIN2+ or CIN3+ at the time each case occurred. For each case, we randomly selected five controls. Cases and controls were aged 26 years or younger when the HPV quadrivalent vaccine became available in 2006. Rate ratios (RRs) from conditional logistic regression were estimated by age at time of first HPV quadrivalent vaccine dose (14-17 years, 18-20 years, and ≥21 years), and number of doses (one, two, and three or more doses) compared with no prior vaccination, with adjustment for smoking, hormonal contraceptive prescription, race or ethnicity, sexually transmitted infections, immunosuppression, parity, and number of outpatient visits.

FINDINGS

4357 incident CIN2+ cases and 21 773 matched controls were included in the study. Of these, 1849 were incident CIN3+ cases with 9242 matched controls. The youngest age at time of first vaccination was 14 years. One or more HPV vaccine doses conferred protection against CIN2+ (RR 0·82, 95% CI 0·73-0·93) and CIN3+ (0·77, 0·64-0·94). We found the strongest protection against CIN2+ in women who had received at least three vaccine doses and had received their first dose aged 14-17 years (0·52, 0·36-0·74) or aged 18-20 years (0·65, 0·49-0·88). No significant protection was found in women aged 21 years or older at time of first dose (0·94, 0·81-1·09). Inferences were similar for CIN3+, but with stronger effects for women who received at least three vaccine doses and had received their first dose aged 14-17 years (0·27, 0·13-0·56) or aged 18-20 years (0·59, 0·36-0·97).

INTERPRETATION

Catch-up quadrivalent HPV vaccination with three doses was effective against CIN2+ and CIN3+ in girls and women aged 14-20 years at time of first vaccine dose but not for women aged 21 years and older at first dose.

FUNDING

US National Cancer Institute.

Simple but not simpler: a systematic review of Markov models for economic evaluation of cervical cancer screening

The aim of this study was to critically evaluate the quality of the models used in economic evaluations of screening strategies for cervical cancer prevention. We systematically searched multiple databases, selecting model-based full economic evaluations (cost-effectiveness analyses, cost-utility analyses, and cost-benefit analyses) of cervical cancer screening strategies. Two independent reviewers screened articles for relevance and performed data extraction. Methodological assessment of the quality of the models utilized formal checklists, and a qualitative narrative synthesis was performed. Thirty-eight articles were reviewed. The majority of the studies were conducted in high-income countries (82%, n=31). The Pap test was the most used screening strategy investigated, which was present in 86% (n=33) of the studies. Half of the studies (n=19) used a previously published Markov model. The deterministic sensitivity analysis was performed in 92% (n=35) of the studies. The mean number of properly reported checklist items was 9 out of the maximum possible 18. Items that were better reported included the statement of decision problem, the description of the strategies/comparators, the statement of time horizon, and information regarding the disease states. Compliance with some items of the checklist was poor. The Markov models for economic evaluation of screening strategies for cervical cancer varied in quality. The following points require improvement: 1) assessment of methodological, structural, heterogeneity, and parameter uncertainties; 2) model type and cycle length justification; 3) methods to account for heterogeneity; and 4) report of consistency evaluation (through calibration and validation methods).

Cancer screening in the United States, 2018: A review of current American Cancer Society guidelines and current issues in cancer screening

Each year, the American Cancer Society publishes a summary of its guidelines for early cancer detection, data and trends in cancer screening rates from the National Health Interview Survey, and select issues related to cancer screening. In this 2018 update, we also summarize the new American Cancer Society colorectal cancer screening guideline and include a clarification in the language of the 2013 lung cancer screening guideline. CA Cancer J Clin 2018;68:297-316. © 2018 American Cancer Society.

Human papillomavirus vaccine effectiveness by number of doses: Systematic review of data from national immunization programs

BACKGROUND

Human papillomavirus (HPV) vaccines were first licensed as a three-dose series; a two-dose series is now recommended in some age groups and there is interest in possible one-dose vaccination.

METHODS

We conducted a systematic literature review of HPV vaccine effectiveness by number of doses, including assessment of biases and impact of varying buffer periods (time between vaccination and outcome counting).

RESULTS

Of 3787 articles identified, 26 full articles were assessed and 14 included in our review. All studies were conducted within the context of recommended three-dose schedules of bivalent (3) or quadrivalent HPV vaccine (11). Two evaluated effectiveness for prevention of HPV prevalence, six anogenital warts, and six abnormal cervical cytology or histology. Many studies found differences between three-, two- and one-dose vaccine recipients, indicating possible differences in HPV exposure prior to vaccination or in risk behavior. Adjusted or stratified analyses were conducted to control for potential confounding. All studies found significant vaccine effectiveness with three doses, 11 with two doses at various intervals, and six with one dose. Most studies showed a relationship (not always statistically significant) between effectiveness and number of doses, with greater decreases in HPV-related outcomes with three, followed by two and one dose(s). Few studies conducted formal comparisons of three vs fewer doses. Three of four studies that examined buffer periods found higher effectiveness and a smaller difference by number of doses with longer periods.

CONCLUSION

Most post-licensure studies report highest effectiveness with three doses; some found no statistically significant difference between two and three doses. Additionally, almost half found some effectiveness with one dose. Several biases impact estimates, with most biasing two- and one-dose results away from showing effectiveness. Future effectiveness studies, examining persons vaccinated prior to sexual activity and using methods to reduce potential sources of bias, can help inform vaccination policy.

Population-based HPV vaccination programmes are safe and effective: 2017 update and the impetus for achieving better global coverage

Persistent oncogenic human papillomavirus (HPV) is the cause of cervical cancer, as well as cancers of the anus, penis, vulva, vagina and oropharynx. There is good evidence that prophylactic HPV vaccines are immunogenic and effective against targeted-type HPV infections and type-specific genital lesions, including high-grade cervical intraepithelial neoplasia (CIN), when administered prior to HPV infection. There is good evidence that HPV vaccines are safe in population usage, with the most frequent adverse event being injection-site reactions. There is evidence to support some cross-protection against non-targeted types occurring following the administration of HPV vaccines. There is limited evidence suggesting that HPV vaccines may be beneficial in preventing future disease in women treated for high-grade CIN. This chapter focuses on the accumulated evidence regarding the global use of the three licensed HPV vaccines including safety, immunogenicity, duration of protection, effectiveness, coverage to date and barriers to higher coverage.

Human Papillomavirus Vaccination and Pap Smear Uptake Among Young Women in the United States: Role of Provider and Patient

BACKGROUND

It has been reported that Pap smear use is higher among U.S. women who received the human papillomavirus (HPV) vaccine than unvaccinated women. This study assessed the role of provider and patient in the difference of Pap smear use by vaccination status.

METHODS

We conducted a cross-sectional study of 5416 young women (21-30 years of age) with detailed information on Pap smear use and HPV vaccination status from the National Health Interview Survey (NHIS) 2013-2015. Vaccinated women received at least one dose of HPV vaccine. Main outcomes included Pap smear in the past year, provider's recommendation for Pap smear, and patient-initiated Pap smear.

RESULTS

The prevalence of Pap smear in the past year was much higher among vaccinated women than unvaccinated women (67.5% vs. 52.8%, p < 0.001). Compared with unvaccinated women, vaccinated women were more likely to receive a provider's recommendation for Pap testing (60.8% vs. 50.8%, p < 0.001), to obtain Pap testing after receiving a provider's recommendation (75.1% vs. 67.9%, p = 0.004), and to initiate Pap testing themselves (57.7% vs. 38.2%, p < 0.001). However, among women who visited an obstetrician/gynecologist (OB/GYN) in the past year, the positive association between HPV vaccination and Pap smear recommendation and uptake vanished.

CONCLUSIONS

Unvaccinated women who have not visited an OB/GYN in the past year are less likely to receive a recommendation for Pap testing from their providers or to initiate Pap testing themselves without a provider's recommendation. They should be encouraged to visit an OB/GYN provider for cervical cancer screening.

Molecular tests potentially improving HPV screening and genotyping for cervical cancer prevention

INTRODUCTION

Human papillomavirus (HPV)-related cancers can be averted by type-specific vaccination (primary prevention) and/or through detection and ablation of precancerous cervical lesions (secondary prevention). This review presents current challenges to cervical cancer screening programs, focusing on recent molecular advances in HPV testing and potential improvements on risk stratification. Areas covered: High-risk (HR)-HPV DNA detection has been progressively incorporated into cervix cancer prevention programs based on its increased sensitivity. Advances in next-generation sequencing (NGS) are being rapidly applied to HPV typing. However, current HPV DNA tests lack specificity for identification of cervical precancer (CIN3). HPV typing methods were reviewed based on published literature, with a focus on these applications for screening and risk stratification in the emerging complex clinical scenario post-vaccine introduction. In addition, the potential for NGS technologies to increase specificity is discussed in regards to reflex testing of specimens for emerging biomarkers for cervix precancer/cancer. Expert commentary: Integrative multi-disciplinary molecular tests accurately triaging exfoliated cervical specimens will improve cervical cancer prevention programs while simplifying healthcare procedures in HPV-infected women. Hence, the concept of a 'liquid-biopsy' (i.e., 'molecular' Pap test) highly specific for early identification of cervical precancerous lesions is of critical importance in the years to come.