Trends in High-Grade Cervical Cancer Precursors in the Human Papillomavirus Vaccine Era

Vulvar Cancer Incidence in the United States and its Relationship to Human Papillomavirus Vaccinations, 2001-2018

The human papillomavirus (HPV) vaccine was indicated for the prevention of vulvovaginal cancers in 2008, but its impact on the incidence of vulvar cancers within the US is unknown. To determine this, we conducted a secondary analysis of 88,942 vulvar cancer cases among women 20+ years old using the US Cancer Statistics 2001-2018 databases. Data were stratified by tumor behavior (in situ or invasive), age (20-44, 45-64, 65+ years old), race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic), and US census region (Northeast, South, Midwest, West), and incidence rates and average annual percentage changes (AAPC) were calculated by group. Reversing previous trends, the incidence of vulvar carcinoma in situ significantly decreased between 2001 and 2018 among women from all age groups, races/ethnicities, and regions (combined AAPC,  -4.3; 95% confidence interval (CI), -4.7 to -3.8). The incidence of invasive vulvar squamous cell carcinoma decreased significantly among 20- to 44-year-old women (AAPC, -0.8; 95% CI, -1.3 to -0.3), but significantly increased among those 45 to 64 (AAPC, 2.3; 95% CI, 1.8-2.8) and 65+ years old (AAPC, 1.2; 95% CI, 1.1-1.4). Regardless of tumor behavior, incidence was highest among non-Hispanic Whites and the Midwest region. Overall, the significant declines in vulvar carcinoma in situ among all ages, as well as invasive vulvar cancer among younger women, are encouraging and complement other recent data suggesting HPV vaccinations are already reducing anal and cervical cancer incidence. Over time, further declines in vulvar carcinoma incidence are likely as uptake and completion rates of the HPV vaccine increase in the US.

PREVENTION RELEVANCE

We found evidence that HPV vaccinations likely contributed to a decrease in the incidences of vulvar carcinoma in situ and invasive vulvar carcinoma among 20- to 44-year-old women between 2001 and 2018. Our data add to the growing evidence that HPV vaccinations are reducing the incidence of HPV-related anogenital cancers.

Human Papillomavirus Vaccine Impact on Cervical Precancers in a Low-Vaccination Population

INTRODUCTION

Demonstrating human papillomavirus vaccine impact is critical for informing guidelines to increase vaccination and decrease human papillomavirus‒related outcomes, particularly in states with suboptimal vaccination coverage, such as Tennessee. This study examines the trends in high-grade cervical lesion incidence among Tennessee Medicaid-enrolled women aged 18-39 years and the subset of women who were screened for cervical cancer.

METHODS

Using a validated claims-based model to identify incident cervical intraepithelial neoplasia Grades 2 or 3 or adenocarcinoma in situ events, annual age group‒specific incidence rates from Tennessee Medicaid billing data, 2008-2018, were calculated. Significant trends were determined by Joinpoint. Analyses were conducted in 2020.

RESULTS

From 2008 to 2018, high-grade cervical lesion incidence significantly declined in women aged 18-20 years (average annual percentage change= -31.9, 95% CI= -38.6, -24.6), 21-24 years (average annual percentage change= -12.9, 95% CI= -22.3, -2.4), and 25-29 years (average annual percentage change= -6.4, 95% CI= -8.1, -4.6). Among screened women, rates significantly declined for ages 18-20 years (average annual percentage change= -20.3, 95% CI= -25.3, -15.0), 21-24 years (average annual percentage change= -10.2, 95% CI= -12.6, -7.8), and 25-29 years (average annual percentage change= -2.6, 95% CI= -3.9, -1.2). Trends from 2008 to 2018 were stable for older age groups (30-34 and 35-39 years).

CONCLUSIONS

Results show reductions in high-grade cervical lesion incidence among ages most likely to have benefited from the human papillomavirus vaccine. Declines among young, screened women suggest causes other than reduction in screening. Evidence of vaccine impact in populations with low-vaccination coverage, such as Tennessee, is promising.

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.

Viral Causality of Human Cancer and Potential Roles of Human Endogenous Retroviruses in the Multi-Omics Era: An Evolutionary Epidemiology Review

Being responsible for almost 12% of cancers worldwide, viruses are among the oldest known and most prevalent oncogenic agents. The quality of the evidence for the in vivo tumorigenic potential of microorganisms varies, thus accordingly, viruses were classified in 4 evidence-based categories by the International Agency for Research on Cancer in 2009. Since then, our understanding of the role of viruses in cancer has significantly improved, firstly due to the emergence of high throughput sequencing technologies that allowed the “brute-force” recovery of unknown viral genomes. At the same time, multi-omics approaches unravelled novel virus-host interactions in stem-cell biology. We now know that viral elements, either exogenous or endogenous, have multiple sometimes conflicting roles in human pathophysiology and the development of cancer. Here we integrate emerging evidence on viral causality in human cancer from basic mechanisms to clinical studies. We analyze viral tumorigenesis under the scope of deep-in-time human-virus evolutionary relationships and critically comment on the evidence through the eyes of clinical epidemiology, firstly by reviewing recognized oncoviruses and their mechanisms of inducing tumorigenesis, and then by examining the potential role of integrated viruses in our genome in the process of carcinogenesis.

Improving Cervical Precancer Surveillance: Validity of Claims-Based Prediction Models in ICD-9 and ICD-10 Eras

Background

Human papillomavirus vaccine (HPV) impact on cervical precancer (cervical intraepithelial neoplasia grades 2+ [CIN2+]) is observable sooner than impact on cancer. Biopsy-confirmed CIN2+ is not included in most US cancer registries. Billing codes could provide surrogate metrics; however, the International Classification of Diseases, ninth (ICD-9) to tenth (ICD-10) transition disrupts trends. We built, validated, and compared claims-based models to identify CIN2+ events in both ICD eras.

Methods

A database of Davidson County (Nashville), Tennessee, pathology-confirmed CIN2+ from the HPV Vaccine Impact Monitoring Project (HPV-IMPACT) provided gold standard events. Using Tennessee Medicaid 2008-2017, cervical diagnostic procedures (N = 8549) among Davidson County women aged 18-39 years were randomly split into 60% training and 40% testing sets. Relevant diagnosis, procedure, and screening codes were used to build models from CIN2+ tissue diagnosis codes alone, least absolute shrinkage and selection operator (LASSO), and random forest. Model-classified index events were counted to estimate incident events.

Results

HPV-IMPACT identified 983 incident CIN2+ events. Models identified 1007 (LASSO), 1245 (CIN2+ tissue diagnosis codes alone), and 957 (random forest) incident events. LASSO performed well in ICD-9 and ICD-10 eras: 77.3% (95% confidence interval [CI] = 72.5% to 81.5%) vs 81.1% (95% CI = 71.5% to 88.6%) sensitivity, 93.0% (95% CI = 91.9% to 94.0%) vs 90.2% (95% CI = 87.2% to 92.7%) specificity, 61.3% (95% CI = 56.6% to 65.8%) vs 60.3% (95% CI = 51.0% to 69.1%) positive predictive value, 96.6% (95% CI = 95.8% to 97.3%) vs 96.3% (95% CI = 94.1% to 97.8%) negative predictive value, 91.0% (95% CI = 89.9% to 92.1%) vs 88.8% (95% CI = 85.9% to 91.2%) accuracy, and 85.1% (95% CI = 82.9% to 87.4%) vs 85.6% (95% CI = 81.4% to 89.9%) C-indices, respectively; performance did not statistically significantly differ between eras (95% confidence intervals all overlapped).

Conclusions

Results confirmed model utility with good performance across both ICD eras for CIN2+ surveillance. Validated claims-based models may be used in future CIN2+ trend analyses to estimate HPV vaccine impact where population-based biopsies are unavailable.

Evaluation of an Inpatient Postpartum Human Papillomavirus Immunization Program

OBJECTIVE

To evaluate the result of an inpatient postpartum human papillomavirus (HPV) immunization pilot program in a diverse, low-income patient population from an urban, hospital-based obstetrics and gynecology clinic.

METHODS

In this cohort study, we present results from the first 2 years of the inpatient postpartum HPV immunization program, in which vaccine-eligible postpartum women were identified and immunized during their hospital stays. The program was implemented after educational outreach with prenatal and postpartum clinicians and nurses. Associations between receipt of the HPV vaccine as an inpatient and the characteristics of patients, and the likelihood of and missed opportunities for receiving a subsequent dose of the HPV vaccine as an outpatient were determined using logistic regression, time-to-event analyses, chi-squared tests and t-tests.

RESULTS

From April 11, 2017, to April 10, 2019, 394 (59.2%) of 666 postpartum women were eligible for the inpatient postpartum HPV immunization program. The majority (265/394, 67.3%) received the immunization pilot program HPV dose; 36 of those 265 (13.6%) completed the series with that dose. Among women due for additional doses after hospital discharge, those who received the inpatient dose were more likely to receive a subsequent outpatient dose (138/229) than were those who did not receive an inpatient dose (39/129; hazard ratio 2.51, 95% CI 1.76-3.58). On average, there were 30.7 fewer (95% CI 5.8-55.6, P<.02) missed opportunities for subsequent outpatient doses for every 100 eligible visits among women who received the inpatient dose, compared with women who did not. By the end of the study, the proportion of women who had completed the vaccine series was higher among women who received the inpatient dose (95/265, 35.8%) than in those who did not (12 out 129, 9.3%; odds ratio 5.45, 95% CI 2.86-10.38).

CONCLUSION

The inpatient postpartum HPV immunization program was associated with increased rates of immunization and addressed a previously missed opportunity. Inpatient immunization programs can serve as a critical way to address gaps in vaccine uptake.

Prevalence of human papillomavirus (HPV)-vaccine types by race/ethnicity and sociodemographic factors in women with high-grade cervical intraepithelial neoplasia (CIN2/3/AIS), Alameda County, California, United States

We evaluated racial/ethnic differences in prevalence of oncogenic HPV types targeted by the quadrivalent HPV vaccine (16/18) and nonavalent HPV vaccine (31/33/45/52/58) in women diagnosed with CIN2/3/AIS after quadrivalent HPV vaccine introduction (2008-2015). Typing data from 1810 cervical tissue specimen from HPV-IMPACT (Alameda County, California, US), a population-based CIN2/3/AIS surveillance effort, were analyzed. Using log-binomial regression, we calculated adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) comparing type prevalence by race/ethnicity, adjusted for health insurance, age, CIN2/3/AIS grade, and time period, overall and in the "early vaccine era" (2008-2011) and "later vaccine era" (2012-2015). Overall, oncogenic HPV16/18 prevalence was significantly lower among black (43%) and Hispanic (43%) women compared with white (52%) women (aPR (95% CI): 0.80 (0.70, 0.93) and 0.80 (0.70, 0.91), respectively). In 2008-2011, proportion of HPV16/18 detected was significantly lower in black (47%), Hispanic (46%), and Asian (42%) women compared to white (58%) women (aPR (95% CI): 0.80 (0.67, 0.96), 0.75 (0.63, 0.90), and 0.73 (0.58, 0.90), respectively). There were no significant differences in 2012-2015. Between the two eras, HPV16/18 prevalence declined in white (-11%), black (-9%), and Hispanic (-6%) women, and increased in Asian women (12%). Decreasing HPV 16/18 prevalence in CIN2/3/AIS lesions in white, black, and Hispanic women may suggest benefit from quadrivalent vaccination. In our unadjusted analysis of HPV31/33/45/52/58, prevalence did not differ significantly by race/ethnicity, but was significantly higher among Hispanic women (32%) compared to white women (27%) after adjustment (aPR (95%CI): 1.22 (1.02, 1.47). Prevalence was also non-significantly higher among black (32%) and Asian (33%) women. This analysis suggests that the nonavalent vaccine's potential for impact against cervical precancers will not be lower in women of color compared to white women. These data underscore the importance of equitable vaccination in facilitating continued declines of vaccine-preventable HPV types among all women.

Trends in anogenital wart incidence among Tennessee Medicaid enrollees, 2006-2014: The impact of human papillomavirus vaccination

Introduction

Evidence of human papillomavirus (HPV) vaccine impact on anogenital warts (AGWs) by race or urbanicity in the US is lacking. We evaluated HPV vaccine impact in Tennessee by assessing AGW trends among Tennessee Medicaid (TennCare) enrollees aged 15–39 years from 2006-2014.

Methods

Persons with incident AGWs were identified using diagnosis/pharmacy codes from TennCare billing claims. We calculated sex-specific annual AGW incidence by age group, race, and urbanicity; estimated annual percent changes (APCs) using log-linear models; and performed pairwise comparisons by race and urbanicity.

Results

AGW incidence decreased among females aged 15–19 (APC = −10.6; P < 0.01) and 20–24 years (APC = −3.9; P = 0.02). Overall trends were similar between Whites and Blacks, and between those living in metropolitan statistical areas (MSAs) and non-MSAs. Rates among males aged 15–19 years began decreasing after 2010. Among enrollees aged 25–39 years, rates increased or were stable.

Conclusions

Following introduction of the HPV vaccine in 2006, AGWs decreased among age groups most likely to be vaccinated. The change in trend among young males after 2010 suggests early herd effects. Our findings indicate vaccine effects and support the importance of improving adherence to current vaccination recommendations for preventing AGWs and other HPV-related diseases.

Addressing HPV vaccine myths: practical information for healthcare providers

Human papillomavirus (HPV) vaccine uptake consistently lags behind that of other adolescent vaccines. In 2017, uptake of a single HPV vaccine dose and HPV vaccine series completion was 66% and 49%, respectively, compared to uptake of tetanus, diphtheria, and acellular pertussis vaccine (89%) and quadrivalent meningococcal conjugate vaccine (85%). Reasons for not vaccinating adolescents again HPV are varied, and in many cases, are rooted in commonly spread myths and misperceptions about the vaccine. In this review, we address five key myths - HPV vaccination is not effective at preventing cancer; Pap smears are sufficient to prevent cervical cancer; HPV vaccination is not safe; HPV vaccination is not needed since most infections are naturally cleared by the immune system; 11-12 years of age is too young to vaccinate. For each myth, we summarize the scientific evidence refuting the myth and provide speaking prompts for healthcare professionals to communicate about HPV vaccination.