Generalized integration model for improved statistical inference by leveraging external summary data

Meta-analysis has become a powerful tool for improving inference by gathering evidence from multiple sources. It pools summary-level data from different studies to improve estimation efficiency with the assumption that all participating studies are analysed under the same statistical model. It is challenging to integrate external summary data calculated from different models with a newly conducted internal study in which individual-level data are collected. We develop a novel statistical inference framework that can effectively synthesize internal and external data for the integrative analysis. The new framework is versatile enough to assimilate various types of summary data from multiple sources. We establish asymptotic properties for the proposed procedure and prove that the new estimate is theoretically more efficient than the internal data based maximum likelihood estimate, as well as a recently developed constrained maximum likelihood approach that incorporates the external information. We illustrate an application of our method by evaluating cervical cancer risk using data from a large cervical screening program.

Racial differences in HPV type 16 prevalence in women with ASCUS of the uterine cervix

BACKGROUND

Understanding racial influences on human papillomavirus (HPV) distribution in women with atypical squamous cells of undetermined significance (ASCUS) cytology via partial genotyping in a statewide population can inform HPV-based prevention efforts.

METHODS

Women aged 21 to 65 years with any cytology result and partial HPV genotyping for ASCUS triage between January 1, 2014, and December 31, 2017, were included. All women attended a Mississippi State Department of Health clinic. Age, race, cytopathologic, and HPV data were extracted from the electronic health record and analyzed. Cytologic specimens were processed with ThinPrep and HPV testing with the Cobas 4800 assay. HPV genotypes were evaluated in hierarchical categories. Chi-square tests and multinomial logistic regression models evaluated associations between race and type prevalence.

RESULTS

There were 43,106 women who underwent cervical cancer screening with cytology and ASCUS triage. Of these, 34,363 (80.2%) had normal cytology, 4672 (10.9%) had ASCUS, 2683 (6.3%) had a low-grade squamous intraepithelial lesion, and 633 (1.5%) had a high-grade squamous intraepithelial lesion. Blacks represented 69.3% of the sample and had a higher proportion of HPV-positive ASCUS (6.5%) in comparison with whites (5.6%). Blacks had significantly decreased odds of HPV-16 (odds ratio [OR], 0.66; 95% confidence interval [CI], 0.6-0.9; P = .002) and significantly increased odds for 12 other types (OR, 1.37; 95% CI, 1.2-1.5; P < .0001) in comparison with whites.

CONCLUSIONS

In a diverse population, significant differences in HPV genotypes are shown by race. Importantly, blacks with ASCUS are less likely to be positive for HPV-16 in comparison with whites. Ongoing work is evaluating the individual genotype prevalence and genotype-specific risk of precancer by race.

A study of the risks of CIN3+ detection after multiple rounds of HPV testing: Results of the 15-year cervical cancer screening experience at Kaiser Permanente Northern California

Many countries are transitioning to HPV testing for cervical cancer screening, despite a lack of long-term experience. To anticipate multi-round screening performance, we analyzed 15-year HPV testing results at Kaiser Permanente Northern California (KPNC). We evaluated HPV test result patterns among women aged 30-64 undergoing triennial HPV/cytology cotesting at KPNC during 2003-2018. We calculated incidence rates and proportion of CIN3+ diagnoses associated with the most frequent HPV testing patterns overall and stratified by age. From 2003 to 2018, a total of 1,361,581 women had a valid HPV test result, and 7,087 were diagnosed with CIN3+. Incidence rates of CIN3+ after HPV positivity were lowest when HPV detection was new and highest in women with prevalent infections (770 vs. 13,910/100,000 person-years). Repeat test negativity reduced subsequent incidence rates of CIN3+ to extremely low levels (18/100,000 person-years following four consecutive negative results). For mixed patterns of positivity/negativity, the recency and frequency of positive tests were associated with increased rates of CIN3+ diagnosis. Most CIN3+ cases (76%) were diagnosed in women who were positive at baseline (the first known positive HPV result); 16% were attributed to apparent newly detected infections and 3% to possible reappearing infections. These results corroborate previous findings that current HPV positivity, particularly when prevalent rather than new, is associated with the highest rates of CIN3+. In a screening program implementing HPV testing, most CIN3+ is detected at the first HPV positive test.

Cervicovaginal microbiome and natural history of HPV in a longitudinal study

BACKGROUND

Human papillomavirus (HPV) infection is one of the most common sexually transmitted infections. However, only a small percentage of high-risk (HR) HPV infections progress to cervical precancer and cancer. In this study, we investigated the role of the cervicovaginal microbiome (CVM) in the natural history of HR-HPV.

METHODS

This study was nested within the placebo arm of the Costa Rica HPV Vaccine Trial that included women aged 18-25 years of age. Cervical samples from two visits of women with an incident HR-HPV infection (n = 273 women) were used to evaluate the prospective role of the CVM on the natural history of HR-HPV. We focus specifically on infection clearance, persistence, and progression to cervical intraepithelial neoplasia grade 2 and 3 (CIN2+). The CVM was characterized by amplification and sequencing the bacterial 16S V4 rRNA gene region and the fungal ITS1 region using an Illumina MiSeq platform. OTU clustering was performed using QIIME2. Functional groups were imputed using PICRUSt and statistical analyses were performed using R.

RESULTS

At Visit 1 (V1) abundance of Lactobacillus iners was associated with clearance of incident HR-HPV infections (Linear Discriminant Analysis (LDA)>4.0), whereas V1 Gardnerella was the dominant biomarker for HR-HPV progression (LDA>4.0). At visit 2 (V2), increased microbial Shannon diversity was significantly associated with progression to CIN2+ (p = 0.027). Multivariate mediation analysis revealed that the positive association of V1 Gardnerella with CIN2+ progression was due to the increased cervicovaginal diversity at V2 (p = 0.040). A full multivariate model of key components of the CVM showed significant protective effects via V1 genus Lactobacillus, OR = 0.41 (0.22-0.79), V1 fungal diversity, OR = 0.90 (0.82-1.00) and V1 functional Cell Motility pathway, OR = 0.75 (0.62-0.92), whereas V2 bacterial diversity, OR = 1.19 (1.03-1.38) was shown to be predictive of progression to CIN2+.

CONCLUSION

This study demonstrates that features of the cervicovaginal microbiome are associated with HR-HPV progression in a prospective longitudinal cohort. The analyses indicated that the association of Gardnerella and progression to CIN2+ may actually be mediated by subsequent elevation of microbial diversity. Identified features of the microbiome associated with HR-HPV progression may be targets for therapeutic manipulation to prevent CIN2+.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00128661.

Identification of HPV genotypes causing cervical precancer using tissue-based genotyping

Identification of high-risk human papillomavirus genotypes causing cervical precancer is crucial for informing HPV vaccine development and efficacy studies, and for determining which types to include in next-generation genotyping assays. Co-occurrence of hrHPV infections is common and complicates carcinogenicity assessment; accurate attribution requires tissue-based genotyping of precancers. We included all women with cervical intraepithelial neoplasia Grade 2 or worse (CIN2+) from the Biopsy Study, an observational study of 690 women enrolled between 2009 and 2012 at the University of Oklahoma. Tissue-based genotyping, including whole tissue sections (WTS) and laser-capture microdissection (LCM), was performed on all precancers with multiple hrHPV infections detected in cytology, totaling over 1,800 HPV genotyping assays. Genotype attribution was compared to hierarchical and proportional hrHPV-type attribution models. Of 276 women with CIN2+, 122 (44.2%) had multiple hrHPV genotypes in cytology. Of 114 women with genotyping data, 94 had one or more hrHPV detected in tissue. Seventy-one women (75.5%) had a single causal hrHPV genotype, while 23 women had multiple hrHPV genotypes causing CIN2+. Ten women had multiple causal infections in a single biopsy, contrary to the previous notion that each lesion is caused by a single type only. While HPV16 was the predominant causal hrHPV genotype using all approaches, the hierarchical model overattributed HPV16, whereas other causal hrHPV genotypes, particularly HPV18 and HPV35, were underattributed. Understanding true causal genotypes is important for the evaluation of vaccine efficacy, to estimate the extent of unmasking, and for type-specific risk assessment in screening and management.

Mutations in the HPV16 genome induced by APOBEC3 are associated with viral clearance

HPV16 causes half of cervical cancers worldwide; for unknown reasons, most infections resolve within two years. Here, we analyze the viral genomes of 5,328 HPV16-positive case-control samples to investigate mutational signatures and the role of human APOBEC3-induced mutations in viral clearance and cervical carcinogenesis. We identify four de novo mutational signatures, one of which matches the COSMIC APOBEC-associated signature 2. The viral genomes of the precancer/cancer cases are less likely to contain within-host somatic HPV16 APOBEC3-induced mutations (Fisher's exact test, P = 6.2 x 10-14), and have a 30% lower nonsynonymous APOBEC3 mutation burden compared to controls. We replicate the low prevalence of HPV16 APOBEC3-induced mutations in 1,749 additional cases. APOBEC3 mutations also historically contribute to the evolution of HPV16 lineages. We demonstrate that cervical infections with a greater burden of somatic HPV16 APOBEC3-induced mutations are more likely to be benign or subsequently clear, suggesting they may reduce persistence, and thus progression, within the host.

Absolute risks of cervical precancer among women who fulfill exiting guidelines based on HPV and cytology cotesting

US guidelines recommend that most women older than 65 years cease cervical screening after two consecutive negative cotests (concurrent HPV and cytology tests) in the previous 10 years, with one in the last 5 years. However, this recommendation was based on expert opinion and modeling rather than empirical data on cancer risk. We therefore estimated the 5-year risks of cervical precancer (cervical intraepithelial neoplasia grade 3 or adenocarcinoma in situ [CIN3]) after one, two and three negative cotests among 346,760 women aged 55-64 years undergoing routine cotesting at Kaiser Permanente Northern California (2003-2015). Women with a history of excisional treatment or CIN2+ were excluded. No woman with one or more negative cotests was diagnosed with cancer during follow-up. Five-year risks of CIN3 after one, two, and three consecutive negative cotests were 0.034% (95% CI: 0.023%-0.046%), 0.041% (95% CI: 0.007%-0.076%) and 0.016% (95% CI: 0.000%-0.052%), respectively (ptrend < 0.001). These risks did not appreciably differ by a positive cotest result prior to the one, two or three negative cotest(s). Since CIN3 risks after one or more negative cotests were significantly below a proposed 0.12% CIN3+ risk threshold for a 5-year screening interval, a longer screening interval in these women is justified. However, the choice of how many negative cotests provide sufficient safety against invasive cancer over a woman's remaining life represents a value judgment based on the harms versus benefits of continued screening. Ideally, this guideline should be informed by longer-term follow-up given that exiting is a long-term decision.

Five-Year Risk of Cervical Precancer Following p16/Ki-67 Dual-Stain Triage of HPV-Positive Women

Importance

As cervical cancer screening transitions to primary human papillomavirus (HPV) testing, effective triage and management of HPV-positive women is critical to avoid unnecessary colposcopy referral and associated harms while maintaining high sensitivity for cervical precancer. Triage with p16/Ki-67 dual-stain (DS) testing has shown high sensitivity and specificity for detection of cervical precancers; however, longitudinal studies are needed to determine the long-term risk of precancer following a negative DS result.

Objective

To evaluate the longitudinal performance of p16/Ki-67 DS triage for detection of cervical precancer in HPV-positive women over 5 years of follow-up in the context of clinical management thresholds.

Design, Setting, and Participants

Prospective cohort study of HPV-positive women 30 years or older undergoing routine cervical cancer screening in 2012 with HPV and Papanicolaou (hereinafter "cytology") co-testing within the Kaiser Permanente Northern California health care system. Follow-up of medical records was conducted through 2017.

Exposures

All p16/Ki-67 DS testing was performed on residual SurePath material, and slides were evaluated for p16/Ki-67 positivity.

Main Outcomes and Measures

Histological end points were ascertained from the clinical database through 2017. We estimated 5-year cumulative risks of cervical intraepithelial neoplasia grades of 2 or worse (≥CIN2) or grades 3 or worse (≥CIN3) by baseline DS and cytology at yearly intervals using Logistic Weibull models. Risks were compared with clinical management thresholds for colposcopy referral and a 1-year return interval.

Results

Among the 1549 HPV-positive women in this study, the mean age at enrollment was 42.2 years, and the median follow-up time was 3.7 years (range, 0.2-5.4 years). Positive DS results were associated with significantly higher cumulative 5-year risks of ≥CIN2 compared with abnormal cytology (31.0%; 95% CI, 27.2%-35.3% vs 25.0%; 95% CI, 21.7%-28.7%; P = .03). Women with DS-negative findings had significantly lower 5-year risks of ≥CIN2 compared with women with normal cytology (8.5%; 95% CI, 6.5%-11.1% vs 12.3%; 95% CI, 9.8%-15.4%; P = .04). In DS-negative women, the risks of both ≥CIN2 and ≥CIN3 remained below the colposcopy referral threshold for all 5 years, crossing the 1-year return threshold at 3 years.

Conclusions and Relevance

Triage with p16/Ki-67 DS provides better long-term risk stratification than cytology over 5 years. The low risk of cervical precancer in p16/Ki-67 DS-negative women permits safe extension of follow-up intervals for 3 years.

Chronic migraine-cephalgia related to trigeminal artery: a case report of innovative regenerative approach

Persistent trigeminal artery (PTA) originates from the posterior bend or lateral wall of the intra-cavernous carotid artery and is the most common occurring type of remnant primitive fetal arteries. In literature, there is limited number of reports on migraine-cephalgia (MC) associated with coexisting PTA. The primitive anastomose arteries that fully belong to the intracranial arterial vascular system are not supposed to perform any supportive functional activity; usually they are subjected to normal biological decay caused by the aging process and metabolic dysfunctions. The hypothesis suggests that these primitive fetal arteries such as PTA may not undergo a fast and structural deterioration but they might be active contributors to a series of mechanisms that can cause a variety of idiopathic complaints. Consequently this would bring a different therapeutic approach other than their surgical removal, which is the accepted option today as a solution for these problems. In this case report, a chronic unilateral MC due to coexisting PTA adjacent to trigeminal nerve is presented. The caliber and location of the PTA was confirmed by a CT-Angiography. The MC treatment was achieved by administration of bio-identical testosterone, human placenta extract (HPE), b-nicotinamide adenine dinucleotide (NADH) and low dose amlopidine.

A systematic review on persistent trigeminal artery, in searching for a therapeutic solution to idiopathic and unresponsive trigeminal nerve inflammations and migraines

The rarely diagnosed persistent trigeminal artery (PTA) originates from the posterior bend or lateral wall of the intracavernous carotid artery and is the most common occurring type of remnant primitive fetal arteries. Even if PTA is uncommon, information and awareness about it could be of great help for clinicians dealing with cranial vascular imaging and operating this region. In addition, it could give a supporting response to the presence of a wide range of idiopathic and unresponsive disturbs that sometimes are erroneously interpreted and treated. There are very few published scientific reports of coexisting PTA and unilateral trigeminal neuralgia and migraine-cephalgia (MC). In this review we describe few reported and unreported cases regarding the manifestation of unresponsive trigeminal neuralgia and migraine due to the presence of PTA. Patients usually present with a clinical symptomatology with unstable blood hypertension, pain of typical trigeminal neuralgia and MC that cover unilaterally the occipital area over the second and third divisions of the nerve. The outbreaks may often become more severe during physical exertion, stress and hypertension. Angio-MRI may reveal the PTA with an occasional occurrence of parietal cavernoma. We also describe a case of chronic left MC case associated with an adjacent PTA close to the trigeminal nerve position. The size and location of the PTA was confirmed by a CT-Angiography. The MC was safely treated by bio-identical testosterone, human placenta extract (HPE), b-nicotinamide adenine dinucleotide (NADH) and low dose amlopidine. It is hypothesized that these types of primitive anastomose arteries that fully belong to the intracranial arterial vascular system do not perform any supportive functional activity. Nevertheless, they undergo the normal biological decay caused by the aging process and metabolic dysfunctions. Therefore, such primitive fetal arteries as PTA might be subjected not only to a faster structural deterioration but they would actively contribute to a series of mechanisms causing a variety of idiopathic intracranial vascular and structural symptoms. Consequently, this would change the primary therapeutic approach to solve this problem, today represented by surgical removal. Anatomic implications related to treatment procedure are also discussed.

Bone decay and beyond: how can we approach it better

Osseo-degeneration is a disorder related to several factors, that may lead to the disruption of several skeletal regions providing support, such as the femur head, the vertebrae and the alveolar bone. The functional condition can be restored by means of grafting procedures, using different materials: calcium powder, xenografts, ceramics and metals. Such procedures aim at reforming an adequate bone volume and strength, that is necessary to support loading forces. Bone regeneration requires that the basic biological principles of osteogenesis, osteoinduction, osteoconduction and biocompatibility are followed. The success of regenerative procedures may depend on the inner structural, mechanical and metabolic condition of the host's bone on which implants should be inserted, on the surgical technique, and on the biomaterial used. Among these, the aging process of the patient appears to be relevant. It can be associated with metabolic disease leading to systemic functional decay, which involves a gradual steady decline of hormonal, immune function and osteo-metabolic activity. The latter can affect the positive outcomes of bone reconstruction and implant therapy. This review will analyze the biological and physiological factors involved in the bone tissue break-down, such as the influences from gut microbiome unbalance and the consequent metabolic, endocrine, immune dysfunctions, the surgery procedures and the quality of the grafting material used. The decline of bone architecture and strength should be corrected by using an appropriate clinical regenerative approach, based on a bio-endocrine, metabolic and immunologic know-how. The final characteristics of the regenerated bone must be able to support the loading forces transmitted by the implants, independent of the body location, and should be individualized according to the different condition of each patient.

Evaluation of TypeSeq, a Novel High-Throughput, Low-Cost, Next-Generation Sequencing-Based Assay for Detection of 51 Human Papillomavirus Genotypes

BACKGROUND

Human papillomaviruses (HPV) cause over 500 000 cervical cancers each year, most of which occur in low-resource settings. Human papillomavirus genotyping is important to study natural history and vaccine efficacy. We evaluated TypeSeq, a novel, next-generation, sequencing-based assay that detects 51 HPV genotypes, in 2 large international epidemiologic studies.

METHODS

TypeSeq was evaluated in 2804 cervical specimens from the Study to Understand Cervical Cancer Endpoints and Early Determinants (SUCCEED) and in 2357 specimens from the Costa Rica Vaccine Trial (CVT). Positive agreement and risks of precancer for individual genotypes were calculated for TypeSeq in comparison to Linear Array (SUCCEED). In CVT, positive agreement and vaccine efficacy were calculated for TypeSeq and SPF10-LiPA.

RESULTS

We observed high overall and positive agreement for most genotypes between TypeSeq and Linear Array in SUCCEED and SPF10-LiPA in CVT. There was no significant difference in risk of precancer between TypeSeq and Linear Array in SUCCEED or in estimates of vaccine efficacy between TypeSeq and SPF10-LiPA in CVT.

CONCLUSIONS

The agreement of TypeSeq with Linear Array and SPF10-LiPA, 2 well established standards for HPV genotyping, demonstrates its high accuracy. TypeSeq provides high-throughput, affordable HPV genotyping for world-wide studies of cervical precancer risk and of HPV vaccine efficacy.

Relative Performance of HPV and Cytology Components of Cotesting in Cervical Screening

Background

The main goal of cervical screening programs is to detect and treat precancer before cancer develops. Human papillomavirus (HPV) testing is more sensitive than cytology for detecting precancer. However, reports of rare HPV-negative, cytology-positive cancers are motivating continued use of both tests (cotesting) despite increased testing costs.

Methods

We quantified the detection of cervical precancer and cancer by cotesting compared with HPV testing alone at Kaiser Permanente Northern California (KPNC), where 1 208 710 women age 30 years and older have undergone triennial cervical cotesting since 2003. Screening histories preceding cervical cancers (n = 623) and precancers (n = 5369) were examined to assess the relative contribution of the cytology and HPV test components in identifying cases. The performances of HPV testing and cytology were compared using contingency table methods, general estimating equation models, and nonparametric statistics; all statistical tests were two-sided.

Results

HPV testing identified more women subsequently diagnosed with cancer (P < .001) and precancer (P < .001) than cytology. HPV testing was statistically significantly more likely to be positive for cancer at any time point (P < .001), except within 12 months (P = .10). HPV-negative/cytology-positive results preceded only small fractions of cases of precancer (3.5%) and cancer (5.9%); these cancers were more likely to be regional or distant stage with squamous histopathology than other cases. Given the rarity of cancers among screened women, the contribution of cytology to screening translated to earlier detection of at most five cases per million women per year. Two-thirds (67.9%) of women found to have cancer during 10 years of follow-up at KPNC were detected by the first cotest performed.

Conclusions

The added sensitivity of cotesting vs HPV alone for detection of treatable cancer affected extremely few women.

Viral coinfection analysis using a MinHash toolkit

BACKGROUND

Human papillomavirus (HPV) is a common sexually transmitted infection associated with cervical cancer that frequently occurs as a coinfection of types and subtypes. Highly similar sublineages that show over 100-fold differences in cancer risk are not distinguishable in coinfections with current typing methods.

RESULTS

We describe an efficient set of computational tools, rkmh, for analyzing complex mixed infections of related viruses based on sequence data. rkmh makes extensive use of MinHash similarity measures, and includes utilities for removing host DNA and classifying reads by type, lineage, and sublineage. We show that rkmh is capable of assigning reads to their HPV type as well as HPV16 lineage and sublineages.

CONCLUSIONS

Accurate read classification enables estimates of percent composition when there are multiple infecting lineages or sublineages. While we demonstrate rkmh for HPV with multiple sequencing technologies, it is also applicable to other mixtures of related sequences.

Clinical Evaluation of Human Papillomavirus Screening With p16/Ki-67 Dual Stain Triage in a Large Organized Cervical Cancer Screening Program

IMPORTANCE

As cervical cancer screening transitions from Papanicolaou cytologic screening to primary human papillomavirus (HPV) testing worldwide, effective triage tests are needed to decide who among the HPV-positive women should receive further diagnostic evaluation to avoid unnecessary colposcopies and biopsies.

OBJECTIVE

To evaluate the performance of the p16/Ki-67 dual stain (DS) and HPV16/18 genotyping for the triage of HPV-positive women.

DESIGN, SETTING, AND PARTICIPANTS

A prospective observational study was conducted within the cervical cancer screening program at Kaiser Permanente Northern California of 3225 HPV-positive women undergoing HPV and Papanicolaou cytologic testing with a valid DS result from September 16 to October 31, 2015, with follow-up through December 31, 2018.

EXPOSURES

Human papillomavirus screening with partial genotyping and cytologic triage compared with DS triage.

MAIN OUTCOMES AND MEASURES

Cervical intraepithelial neoplasia grade 3 or more severe (CIN3+) and grade 2 or more severe (CIN2+), diagnosed within 3 years after sample collection.

RESULTS

A total of 3225 women (mean [SD] age, 37.9 [11.3] years) participated in the study. For triage of HPV-positive women with partial genotyping, DS showed better risk stratification for CIN3+ than did Papanicolaou cytologic testing, with women with positive DS results having a higher risk than women with positive Papanicolaou test results for CIN3+ (218 of 1818 [12.0%; 95% CI, 10.5%-13.5%] vs 219 of 2128 [10.3%; 95% CI, 9.0%-11.6%]; P = .005). Similarly, DS showed better risk stratification for CIN3+ compared with Papanicolaou cytologic testing in HPV-positive women, irrespective of genotyping. The greatest reassurance against CIN3+ was observed in HPV16/18-negative women with negative DS results, with a risk low enough to extend retesting intervals. Dual stain triage strategies required substantially fewer colposcopies per detection of CIN3+ compared with Papanicolaou cytologic testing, with a 32.1% (859 of 2677) reduction of colposcopies compared with the currently recommended triage strategy of HPV screening with Papanicolaou cytologic testing. Results for CIN2+ were very similar.

CONCLUSIONS AND RELEVANCE

Triage of HPV-positive women with DS was superior to Papanicolaou cytologic testing in this study, demonstrating equal immediate detection of precancerous lesions and substantially reduced referral to colposcopy. These findings suggest that DS can safely replace Papanicolaou cytologic testing as a triage strategy for primary HPV screening, and that retesting intervals in HPV16/18-negative women with negative DS results can be safely extended to 3 years.

False positive cervical HPV screening test results

In cervical cancer screening, HPV testing is best at reassuring women when they are negative, but proper management of HPV positives is still evolving. Most HPV infections are benign, and over-reacting clinically to HPV positivity can cause psychological and possible iatrogenic physical (e.g., obstetrical) harm. We describe the built-in false positives in current tests, and the real harm that can result when the meaning of such false positive HPV tests is misunderstood. We suggest steps that could reduce harm being done by flawed tests and excessive clinical responses to positive HPV testing. We focus the discussion by presenting an illustrative case.

Human papillomavirus 16 sub-lineage dispersal and cervical cancer risk worldwide: Whole viral genome sequences from 7116 HPV16-positive women

BACKGROUND

Human papillomavirus (HPV)16 can be separated into genetic sub-lineages (A1-4, B1-4, C1-4, D1-4) which may have differential cervical cancer risk.

METHODS

A next-generation sequencing assay was used to whole-genome sequence 7116 HPV16-positive cervical samples from well-characterised international epidemiological studies, including 2076 controls, 1878 squamous cell carcinoma (SCC) and 186 adenocarcinoma/adenosquamous cell carcinoma (ADC), and to assign HPV16 sub-lineage. Logistic regression was used to estimate region-stratified country-adjusted odds ratios (OR) and 95%CI.

RESULTS

A1 was the most globally widespread sub-lineage, with others showing stronger regional specificity (A3 and A4 for East Asia, B1-4 and C1-4 for Africa, D2 for the Americas, B4, C4 and D4 for North Africa). Increased cancer risks versus A1 were seen for A3, A4 and D (sub)lineages in regions where they were common: A3 in East Asia (OR=2.2, 95%CI:1.0-4.7); A4 in East Asia (6.6, 3.1-14.1) and North America (3.8, 1.7-8.3); and D in North (6.2, 4.1-9.3) and South/Central America (2.2, 0.8-5.7), where D lineages were also more frequent in ADC than SCC (3.2, 1.5-6.5; 12.1, 5.7-25.6, respectively).

CONCLUSIONS

HPV16 genetic variation can strongly influence cervical cancer risk. However, burden of cervical cancer attributable to different sub-lineages worldwide is largely driven by historical HPV16 sub-lineage dispersal.

Changes in DNA Level of Oncogenic Human Papillomaviruses Other Than Types 16 and 18 in Relation to Risk of Cervical Intraepithelial Neoplasia Grades 2 and 3

BACKGROUND

Epidemiologic data addressing clinical relevance of viral load fluctuation of oncogenic types other than human papillomavirus (HPV) types 16 and 18 are limited.

METHODS

A type-stratified set of infections by non-HPV16/18 oncogenic types that were detected at ≥2 visits was randomly selected from women who were enrolled in a clinical trial and followed every 6 months for 2 years for detection of HPV and cervical intraepithelial neoplasia grades 2 and 3 (CIN2/3). Type-specific viral load was measured on both first and last HPV-positive cervical swab samples.

RESULTS

CIN2/3 was initially confirmed at the last HPV-positive visit for 67 of 439 infections. The increase in risk of CIN2/3 was associated with high, relative to low, viral load at both first and last positive visits [OR_adjusted = 3.67; 95% confidence interval (CI), 1.19-11.32] and marginally associated with a change of viral load from low to high levels (OR_adjusted = 3.15; 95% CI, 0.96-10.35) for infection by species group alpha-9 non-HPV16 oncogenic types but not species group alpha-5-7 non-HPV18 oncogenic types. Among women with an initial diagnosis of CIN2/3 at the first positive visit, CIN2/3 was more frequently redetected at the last positive visit for infections with, compared with without, high DNA load of species group alpha-9 non-HPV16 oncogenic types at both visits (P _exact = 0.04).

CONCLUSIONS

In agreement with data on baseline viral load, the viral load change-associated risk of CIN2/3 differs by HPV species groups.

IMPACT

These findings underscore the importance of distinguishing species groups in future studies of clinical relevance of HPV DNA load.

Development of the TypeSeq Assay for Detection of 51 Human Papillomavirus Genotypes by Next-Generation Sequencing

We have developed a new human papillomavirus (HPV) genotyping assay for detection of 51 HPV genotypes by next-generation sequencing (NGS). The TypeSeq assay consists of 3 PCR steps that equalize viral load and each type's amplicon copies prior to genotyping by NGS, thereby maximizing multiple-type sensitivity with minimal sequencing reads. The analytical sensitivity of the TypeSeq assay is 10 copies per reaction for 49 of the 51 types, including 13 high-risk (HR) types. We tested 863 clinical cervical specimens previously evaluated with the Roche Linear Array HPV genotyping test (LA). TypeSeq achieved 94.4% positive agreement with LA for detection of any HR type. Positive agreement was 91.4% and 85.5% for HPV16 and HPV18, respectively. Low-risk (LR) types ranged from 40.0% positive agreement (HPV83) to 90.9% (HPV69). Our unique approach to HPV amplification achieved a multiple-type sensitivity comparable to that of LA, with 83.9% and 84.2% of specimens positive for multiple HPV types by TypeSeq or LA, respectively. A total of 48.2% of specimens showed perfect agreement for all 37 types common to both assays. The simplicity of our open-source TypeSeq assay allows for high-throughput yet scalable processing, with a single technician able to process up to 768 specimens within 3 days. By leveraging NGS sample multiplexing capabilities, the per-sample labor requirements are greatly reduced compared to those of traditional genotyping methods. These features and the broad spectrum of detectable types make TypeSeq highly suitable for a wide range of applications.

Cytologic patterns of cervical adenocarcinomas with emphasis on factors associated with underdiagnosis

BACKGROUND

New cervical cancers continue to be diagnosed despite the success of Papanicolaou (Pap) tests. In an effort to identify pitfalls that limit the diagnosis of adenocarcinoma, the authors reviewed the cytologic characteristics of endocervical adenocarcinomas in their patient population.

METHODS

Liquid-based cytology slides from 45 women who had concurrent, histologically confirmed cervical adenocarcinomas were reviewed retrospectively and semiquantitatively for 25 key cytologic traits. The original sign-out diagnosis, available clinical findings, and high-risk human papillomavirus (HR HPV) results also were noted.

RESULTS

Abundant tumor cellularity, nuclear size from 3 to 6 times normal, abundant 3-dimensional tumor cell groups, round cell shape, and cytoplasmic neutrophils characterized the 23 cases that were identified correctly as adenocarcinomas. Key reasons for undercalls included low tumor cellularity and low-grade columnar morphology; these also tended to correlate with low-grade or unusual adenocarcinoma variants on histology. Overall, 73% of adenocarcinomas had a concurrent positive HR HPV test.

CONCLUSIONS

Most endocervical adenocarcinomas can be diagnosed accurately in cases with classical features, but some cases continue to be problematic when evaluated based on cytologic features alone. Reflex HPV testing may help increase Pap test sensitivity for challenging cases that have atypical glandular cells of undetermined significance. Occasional cases with negative HR HPV test results remain of concern.

Automated Cervical Screening and Triage, Based on HPV Testing and Computer-Interpreted Cytology

Background

State-of-the-art cervical cancer prevention includes human papillomavirus (HPV) vaccination among adolescents and screening/treatment of cervical precancer (CIN3/AIS and, less strictly, CIN2) among adults. HPV testing provides sensitive detection of precancer but, to reduce overtreatment, secondary "triage" is needed to predict women at highest risk. Those with the highest-risk HPV types or abnormal cytology are commonly referred to colposcopy; however, expert cytology services are critically lacking in many regions.

Methods

To permit completely automatable cervical screening/triage, we designed and validated a novel triage method, a cytologic risk score algorithm based on computer-scanned liquid-based slide features (FocalPoint, BD, Burlington, NC). We compared it with abnormal cytology in predicting precancer among 1839 women testing HPV positive (HC2, Qiagen, Germantown, MD) in 2010 at Kaiser Permanente Northern California (KPNC). Precancer outcomes were ascertained by record linkage. As additional validation, we compared the algorithm prospectively with cytology results among 243 807 women screened at KPNC (2016-2017). All statistical tests were two-sided.

Results

Among HPV-positive women, the algorithm matched the triage performance of abnormal cytology. Combined with HPV16/18/45 typing (Onclarity, BD, Sparks, MD), the automatable strategy referred 91.7% of HPV-positive CIN3/AIS cases to immediate colposcopy while deferring 38.4% of all HPV-positive women to one-year retesting (compared with 89.1% and 37.4%, respectively, for typing and cytology triage). In the 2016-2017 validation, the predicted risk scores strongly correlated with cytology (P < .001).

Conclusions

High-quality cervical screening and triage performance is achievable using this completely automated approach. Automated technology could permit extension of high-quality cervical screening/triage coverage to currently underserved regions.

Niche adaptation and viral transmission of human papillomaviruses from archaic hominins to modern humans

Recent discoveries on the origins of modern humans from multiple archaic hominin populations and the diversity of human papillomaviruses (HPVs) suggest a complex scenario of virus-host evolution. To evaluate the origin of HPV pathogenesis, we estimated the phylogeny, timing, and dispersal of HPV16 variants using a Bayesian Markov Chain Monte Carlo framework. To increase precision, we identified and characterized non-human primate papillomaviruses from New and Old World monkeys to set molecular clock models. We demonstrate specific host niche adaptation of primate papillomaviruses with subsequent coevolution with their primate hosts for at least 40 million years. Analyses of 212 HPV16 complete genomes and 3582 partial sequences estimated ancient divergence of HPV16 variants (between A and BCD lineages) from their most recent common ancestors around half a million years ago, roughly coinciding with the timing of the split between archaic Neanderthals and modern Homo sapiens, and nearly three times longer than divergence times of modern Homo sapiens. HPV16 A lineage variants were significantly underrepresented in present African populations, whereas the A sublineages were highly prevalent in European (A1-3) and Asian (A4) populations, indicative of viral sexual transmission from Neanderthals to modern non-African humans through multiple interbreeding events in the past 80 thousand years. Remarkably, the human leukocyte antigen B*07:02 and C*07:02 alleles associated with increased risk in cervix cancer represent introgressed regions from Neanderthals in present-day Eurasians. The archaic hominin-host-switch model was also supported by other HPV variants. Niche adaptation and virus-host codivergence appear to influence the pathogenesis of papillomaviruses.

How confident can we be in the current guidelines for exiting cervical screening?

Current US guidelines recommend against cervical screening beyond age 65 in women who have had adequate negative screening. In anticipation of the next round of evidence review and guideline updates, we provide a critical review of the evidence supporting the exiting recommendation in the US, highlighting both practice changes and new insights into the epidemiology and natural history of HPV and cervical cancer. Current recommendations are based, by necessity, on cytology alone, and will be limited in generalizability to evolving screening strategies with co-testing and primary HPV testing. The lack of empirical data to define what constitutes 'adequate recent screening with negative results' is compounded by difficulties in predicting future risk without consideration of concepts of HPV latency and cohort effects of changing sexual behaviour in US women over time. We urge caution in extrapolating past risk experience in post-menopausal women to today's population, and suggest study designs to strengthen the evidence base in well-screened older women. We further recommend building the qualitative evidence base to better define the harms and benefits of screening among older women. Extending the lifetime of screening is a matter of finding the appropriate balance of benefits of cancer reduction and limitation of harms and costs of 'overscreening'. This will require moving beyond current emphasis on number of colposcopies as the metric of harm. Our commentary is meant to stimulate intellectual debate regarding the certainty of our existing knowledge base and set clear research priorities for the future.