Impact of cervical screening by human papillomavirus genotype: Population-based estimations.

BACKGROUND: Cervical screening programs use testing for human papillomavirus (HPV) genotypes. Different HPV types differ greatly in prevalence and oncogenicity. We estimated the impact of cervical screening and follow-up for each HPV type. METHODS AND FINDINGS: For each type of HPV, we calculated the number of women needed to screen (NNS) and number of women needing follow-up (NNF) to detect or prevent one cervical cancer case, using the following individual level input data (i) screening and cancer data for all women aged 25 to 80 years, resident in Sweden during 2004 to 2011 (N = 3,568,938); (ii) HPV type-specific prevalences and screening histories among women with cervical cancer in Sweden in 2002 to 2011(N = 4,254); (iii) HPV 16/18/other HPV prevalences in the population-based HPV screening program (N = 656,607); and (iv) exact HPV genotyping in a population-based cohort (n = 12,527). Historical screening attendance was associated with a 72% reduction of cervical cancer incidence caused by HPV16 (71.6%, 95% confidence interval (CI) [69.1%, 73.9%]) and a 54% reduction of cancer caused by HPV18 (53.8%, 95% CI [40.6%, 63.1%]). One case of HPV16-caused cervical cancer could be prevented for every 5,527 women attending screening (number needed to screen, NNS). Prevention of one case of HPV16-caused cervical cancer required follow-up of 147 HPV16-positive women (number needed to follow-up, NNF). The NNS and NNF were up to 40 to 500 times higher for HPV types commonly screened for with lower oncogenic potential (HPV35,39,51,56,59,66,68). For women below 30 years of age, NNS and NNF for HPV16 were 4,747 and 289, respectively, but >220,000 and >16,000 for HPV35,39,51,56,59,66,68. All estimates were either age-standarized or age-stratified. The primary limitation of our study is that NNS is dependent on the HPV prevalence that can differ between populations and over time. However, it can readily be recalculated in other settings and monitored when HPV type-specific prevalence changes. Other limitations include that in some age groups, there was little data and extrapolations had to be made. Finally, there were very few cervical cancer cases associated with certain HPV types in young age group. CONCLUSIONS: In this study, we observed that the impact of cervical cancer screening varies depending on the HPV type screened for. Estimating and monitoring the impact of screening by HPV type can facilitate the design of effective and efficient HPV-based cervical screening programs. TRIAL REGISTRATION: ClinicalTrials.gov with numbers NCT00479375, NCT01511328.

The International Human Papillomavirus Reference Center: Standardization, collaboration, and quality assurance in HPV research and diagnostics.

The International Human Papillomavirus (HPV) Reference Center (IHRC) confirms and assigns type numbers to novel HPV types, maintains a reference clone repository, and issues international proficiency panels for HPV screening and genotyping. Furthermore, the Center coordinates the Global HPV Reference Laboratory Network that promotes collaboration and international exchange of experiences among national HPV reference laboratories, to further international standardization and quality assurance in the HPV field. The established HPV types (n = 225) belong to 5 different genera: alpha (n = 65), beta (n = 54), gamma (n = 102), mu (n = 3) and nu (n = 1). Since the last published IHRC overview in 2018, 6 novel types have been established, with 5/6 belonging to the gamma genus and 1/6 to beta genus. Also, 474 reference clones have been provided to 55 different research laboratories and the global proficiency program for HPV genotyping has seen an increasing proficiency (despite a decrease seen in 2019), from 68% proficiency in 2017 to 77.3% in 2022. The first proficiency study for HPV screening found an international proficiency of up to 77%. In summary, increasing complexity of the HPVs and demands on quality assurance in the era of cervical cancer elimination requires international efforts to support proficiency and recognized quality and order among HPV types.

Head-to-Head Comparison of Bi- and Nonavalent Human Papillomavirus Vaccine-Induced Antibody Responses.

For head-to-head comparison of human papillomavirus (HPV) antibody levels induced by different vaccines, 25-year-old vaccine-naive women were given either the bivalent (n = 188) or the nonavalent HPV vaccine (n = 184). Six months after vaccination antibodies against pseudovirions from 17 different HPV types (HPV6/11/16/18/31/33/35/39/45/51/52/56/58/59/66/68/73) were measured. Antibodies against HPV16/18 were higher after bivalent HPV vaccination (mean international units [IU] 1140.1 and 170.5 for HPV16 and 18, respectively) than after nonavalent vaccination (265.1 and 22.3 IUs, respectively). The bivalent vaccine commonly induced antibodies against the nonvaccine HPV types 31/33/35/45 or 58. The nonavalent vaccine induced higher antibodies against HPV6/11/31/33/45/52/58 and 35.

High Amounts of SARS-CoV-2 Precede Sickness Among Asymptomatic Health Care Workers.

BACKGROUND: Whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positivity among asymptomatic subjects reflects past or future disease may be difficult to ascertain. METHODS: We tested 9449 employees at Karolinska University Hospital, Stockholm, Sweden for SARS-CoV-2 RNA and antibodies, linked the results to sick leave records, and determined associations with past or future sick leave using multinomial logistic regression. RESULTS: Subjects with high amounts of SARS-CoV-2 virus, indicated by polymerase chain reaction (PCR) cycle threshold (Ct) value, had the highest risk for sick leave in the 2 weeks after testing (odds ratio [OR], 11.97; 95% confidence interval [CI], 6.29-22.80) whereas subjects with low amounts of virus had the highest risk for sick leave in the 3 weeks before testing (OR, 6.31; 95% CI, 4.38-9.08). Only 2.5% of employees were SARS-CoV-2 positive while 10.5% were positive by serology and 1.2% were positive in both tests. Serology-positive subjects were not at excess risk for future sick leave (OR, 1.06; 95% CI, .71-1.57). CONCLUSIONS: High amounts of SARS-CoV-2 virus, as determined using PCR Ct values, was associated with development of sickness in the next few weeks. Results support the concept that PCR Ct may be informative when testing for SARS-CoV-2. Clinical Trials Registration. NCT04411576.

Organized primary human papillomavirus-based cervical screening: A randomized healthcare policy trial.

BACKGROUND: Clinical trials in the research setting have demonstrated that primary human papillomavirus (HPV)-based screening results in greater protection against cervical cancer compared with cytology, but evidence from real-life implementation was missing. To evaluate the effectiveness of HPV-based cervical screening within a real-life screening program, the organized, population-based cervical screening program in the capital region of Sweden offered either HPV- or cytology-based screening in a randomized manner through a randomized healthcare policy (RHP). METHODS AND FINDINGS: A total of 395,725 women aged 30 to 64 years that were invited for their routine cervical screening visit were randomized without blinding to either cytology-based screening with HPV triage (n = 183,309) or HPV-based screening, with cytology triage (n = 212,416 women) between September 1, 2014 and September 30, 2016 and follow-up through June 30, 2017. The main outcome was non-inferior detection rate of cervical intraepithelial neoplasia grade 2 or worse (CIN2+). Secondary outcomes included superiority in CIN2+ detection, screening attendance, and referral to histology. In total, 120,240 had a cervical screening sample on record in the study period in the HPV arm and 99,340 in the cytology arm and were followed for the outcomes of interest. In per-protocol (PP) analyses, the detection rate of CIN2+ was 1.03% (95% confidence interval (CI) 0.98 to 1.10) in the HPV arm and 0.93% (0.87 to 0.99) in the cytology arm (p for non-inferiority <0.0001; odds ratio (OR) 1.11 (95% CI 1.02 to 1.22)). There were 46 cervical cancers detected in the HPV arm (0.04% (0.03 to 0.06)) and 48 cancers detected in the cytology arm (0.05% (0.04 to 0.07)) (p for non-inferiority <0.0001; OR 0.79 (0.53 to 1.18)). Intention-to-screen (ITS) analyses found few differences. In the HPV arm, there was a modestly increased attendance after new invitations (68.56% (68.31 to 68.80) vs. 67.71% (67.43 to 67.98); OR 1.02 (1.00 to 1.03)) and increased rate of referral with completed biopsy (3.89% (3.79 to 4.00) vs. 3.53% (3.42 to 3.65); OR 1.10 (1.05 to 1.15)). The main limitations of this analysis are that only the baseline results are presented, and there was an imbalance in invitations between the study arms. CONCLUSIONS: In this study, we observed that a real-life RHP of primary HPV-based screening was acceptable and effective when evaluated against cytology-based screening, as indicated by comparable participation, referral, and detection rates. TRIAL REGISTRATION: ClinicalTrials.gov NCT01511328.

Differing Age-Specific Cervical Cancer Incidence Between Different Types of Human Papillomavirus: Implications for Predicting the Impact of Elimination Programs.

The elimination of cervical cancer rests on high efficacy of human papillomavirus (HPV) vaccines. The HPV type distribution among cases of invasive cervical cancer (ICC) is used to make predictions about the impact of eliminating different types of HPV, but accumulating evidence of differences in age-specific cancer incidence by HPV type exists. We used one of the largest population-based series of HPV genotyping of ICCs (n = 2,850; Sweden, 2002-2011) to estimate age-specific ICC incidence by HPV type and obtain estimates of the cancer-protective impact of the removal of different HPV types. In the base case, the age-specific ICC incidence had 2 peaks, and the standardized lifetime risk (SLTR, the lifetime number of cases per birth cohort of 100,000 females) for HPV-positive ICC was 651 per 100,000 female births. In the absence of vaccine types HPV 16 and HPV 18, the SLTR for ICC was reduced to 157 per 100,000 female births (24% of HPV-positive SLTR). Elimination of all 9 types that can currently be vaccinated against reduced the remaining SLTR to 47 per 100,000 female births (7%), the remaining ICC incidence only slowly increasing with age. In conclusion, after elimination of vaccine-protected HPV types, very few cases of ICC will be left, especially among fertile, reproductive-age women.

Human papillomavirus types in cervical dysplasia among young HPV-vaccinated women: Population-based nested case-control study.

Human papillomavirus (HPV) vaccines protect against infections with the most oncogenic HPV types, cervical intraepithelial neoplasia (CIN) and cervical cancer. We investigated whether development of cervical intraepithelial neoplasia (CIN) lesions in HPV-vaccinated women is associated with vaccine-targeted HPV types or not. Linkage of the Swedish vaccination and cervical screening registries identified all females born 1980-2000 who had been HPV vaccinated before December 31, 2014 (n = 305,320) and had attended cervical screening in 2006-2018 (n = 79,491). We further selected women HPV vaccinated below 17 years of age and screened in the capital region (n = 5,874). Among those, 125 developed CIN and had a cervical cryopreserved sample available (42.5% of all eligible CIN cases). After 1:2 matching to disease-free HPV vaccinated controls (n = 242), samples were analyzed for HPV DNA and associations between HPV type and CIN diagnosis were estimated with conditional logistic regression. Vaccine-targeted HPV types were rare among both CIN cases (2.4% HPV16, 0.8% HPV18) and their matched controls (0.4% HPV16 and 18). No woman had HPV6 or 11. The CIN lesions were associated with the nonvaccine HPV types 31, 33, 42, 45, 51, 52, 56, 59 and 66. CIN lesions among young HPV vaccinated women are mostly attributable to infection with nonvaccine HPV types. The phenomenon may be important for surveillance and design of cervical cancer control strategies.

Deep sequencing detects human papillomavirus (HPV) in cervical cancers negative for HPV by PCR.

BACKGROUND: Human papillomavirus (HPV) is a necessary cause of cervical cancer, although some invasive cervical cancers may test negative by HPV PCR. We previously requested all invasive cervical cancers in Sweden during 10 years and subjected them to PCR. We also optimised methods for deep sequencing of formalin-fixed paraffin-embedded samples. METHODS: Using Novaseq 6000, we simultaneously sequenced total DNA and cDNA from 392 HPV PCR-negative cervical cancers. Non-human reads were queried against all known HPVs. The complete database now contains PCR and/or deep sequencing data on 2850 invasive cervical cancers. RESULTS: HPV sequences were detected in 169/392 of HPV PCR-negative cervical cancers. Overall, 30 different HPV types were detected, but only 5 types were present in proportions above 3% of cancers. More than 92% of tumours were HPV-positive in PCR and/or sequencing (95% confidence interval: 91.1-93.1%). Exploring possible reasons for failure to previously detect HPV suggest that more sensitive type-specific PCRs for HPV 31, 33, 45 and 73 targeting retained regions of HPV would have detected most of these (117/392). CONCLUSIONS: Unbiased deep sequencing provides comprehensive data on HPV types in cervical cancers and appears to be an important tool for quality assurance of HPV screening.

Sequencing detects human papillomavirus in some apparently HPV-negative invasive cervical cancers.

Introduction. Cervical cancer is caused by human papillomavirus (HPV), but some cases may test HPV-negative. We previously tested 2850 Swedish cases and found that 394/2850 (13.8 %) cases tested HPV DNA-negative by PCR. Sequencing is the most thorough method to assess HPV status.Aim. We wished to assess whether deep sequencing might detect HPV sequences among these HPV-negative cervical cancer specimens, and to increase the likelihood of detecting transcriptionally active infections.Methodology. Out of the 2850 cancer cases, we sequenced a random sample of 92 HPV PCR-negative cervical cancers and 34 HPV PCR-positive cervical cancers. Four pools of blank blocks were sequenced as negative controls. To enrich for mRNA - a hallmark of active viral infection - the samples were extracted, reverse-transcribed, rRNA-depleted and then sequenced using the NovaSeq 6000 system (Illumina, USA). High-quality reads were aligned to the human genome and non-human reads were queried against HPV proteins.Results. We obtained a median of 23 million paired reads per sample. HPV was detected in 31/34 HPV PCR-positive cases. Among cases negative for HPV by PCR, 48/92 (52.2 %) contained HPV sequences, with HPV33 being the most commonly detected type among these (14/48 cases, 29.2 %). Comparison of the ratio of exon and intron sequences found that the sequenced material contained both DNA and RNA. Splice junctions were detected in 12 cases.Conclusion. Apparently, some cervical cancers contain HPV that is difficult to detect by PCR. Sequencing may be a helpful tool for additional quality assurance for HPV testing methods.

Colposcopic and histopathologic evaluation of women with HPV persistence exiting an organized screening program.

BACKGROUND: Human papillomavirus-based screening has a higher sensitivity for precursors of cervical cancer compared with cytology-based screening. However, more evidence is needed on optimal management of human papillomavirus-positive women. OBJECTIVE: The objective of the study was to compare the risk of histopathologically confirmed cervical intraepithelial lesions grade 2 or worse after 1 and 3 years of human papillomavirus persistence, respectively, and evaluate the clinical management of human papillomavirus-positive women in the 56-60 year age group. STUDY DESIGN: This was a randomized health care policy offering human papillomavirus screening to 50% of resident women aged 56-60 years in the Stockholm/Gotland region of Sweden during January 2012 through May 2014. Women who were human papillomavirus positive/cytology negative at baseline were referred for a repeat test after 1 or 3 years. In case of human papillomavirus persistence, women were referred for colposcopy, including biopsies and endocervical sampling. RESULTS: The human papillomavirus prevalence was 5.5% (405 women of 7325 attending). Among the 405 human papillomavirus-positive women, 313 were reflex test cytology negative at baseline and were referred for a repeat human papillomavirus test, 176 women after 1 year and 137 women after 3 years. After 1 year, 91 of 176 (52%) were persistently human papillomavirus positive and after 3 years 55 of 137 (40%) (P = .042). In repeat cytology, 10 of the 91 (12%) were positive after 1 year and 15 of 55 (33%) after 3 years (P = .005). The attendance rates for colposcopy were similar: 82 of 91 (90%) in the 1 year group and 45 of 55 (82%) in the 3 year group. All women attending colposcopy were postmenopausal, and endocervical sampling and punch biopsies were performed to facilitate colposcopic management, with a positive predictive value of 43-50% and 28-31%, respectively. Histopathologically confirmed cervical intraepithelial lesions grade 2 or worse was found in 19 of 82 women (23%) and 9 of 45 women (20%) in the 1 year and 3 year groups, respectively, and registry linkage follow-up found no cancers in either group. Human papillomavirus genotyping was predictive of cervical intraepithelial lesions grade 2 or worse, and human papillomavirus 16 was the most common genotype at human papillomavirus persistence, occurring in 18% of the cases in the 1 year group and 20% in the 3 year group. CONCLUSION: It was safe to postpone repeat human papillomavirus tests for 3 years in postmenopausal women attending the organized cervical screening program. There was a high risk for cervical intraepithelial lesions grade 2 or worse at follow-up and noteworthy yields from human papillomavirus genotyping as well as endocervical sampling and random biopsies in the absence of visible colposcopic lesions.

Increasing participation in cervical screening by targeting long-term nonattenders: Randomized health services study.

High screening participation in the population is essential for optimal prevention of cervical cancer. Offering a high-risk human papillomavirus (HPV) self-test has previously been shown to increase participation. In this randomized health services study, we evaluated four strategies with regard to participation. Women who had not attended organized cervical screening in 10 years were eligible for inclusion. This group comprised 16,437 out of 413,487 resident women ages 33-60 (<4% of the screening target group). Among these 16,437 long-term nonattenders, 8,000 women were randomized to either (i) a HPV self-sampling kit sent directly; (ii) an invitation to order a HPV self-sampling kit using a new open source eHealth web application; (iii) an invitation to call a coordinating midwife with questions and concerns; or (iv) the standard annual renewed invitation letter with prebooked appointment time (routine practice). Overall participation, by arm, was (i) 18.7%; (ii) 10.7%; (iii) 1.9%; and (iv) 1.7%. The relative risk of participation in Arm 1 was 11.0 (95% CI 7.8-15.5), 6.3 (95% CI 4.4-8.9) in Arm 2 and 1.1 (95% CI 0.7-1.7) in Arm 3, compared to Arm 4. High-risk HPV prevalence among women who returned kits in study Arms 1 and 2 was 12.2%. In total, 63 women were directly referred to colposcopy from Arms 1 and 2; of which, 43 (68.3%) attended and 17 had a high-grade cervical lesion (CIN2+) in histology (39.5%). Targeting long-term nonattending women with sending or offering the opportunity to order self-sampling kits further increased the participation in an organized screening program.

High-risk human papillomavirus status and prognosis in invasive cervical cancer: A nationwide cohort study.

BACKGROUND: High-risk human papillomavirus (hrHPV) infection is established as the major cause of invasive cervical cancer (ICC). However, whether hrHPV status in the tumor is associated with subsequent prognosis of ICC is controversial. We aim to evaluate the association between tumor hrHPV status and ICC prognosis using national registers and comprehensive human papillomavirus (HPV) genotyping. METHODS AND FINDINGS: In this nationwide population-based cohort study, we identified all ICC diagnosed in Sweden during the years 2002-2011 (4,254 confirmed cases), requested all archival formalin-fixed paraffin-embedded blocks, and performed HPV genotyping. Twenty out of 25 pathology biobanks agreed to the study, yielding a total of 2,845 confirmed cases with valid HPV results. Cases were prospectively followed up from date of cancer diagnosis to 31 December 2015, migration from Sweden, or death, whichever occurred first. The main exposure was tumor hrHPV status classified as hrHPV-positive and hrHPV-negative. The primary outcome was all-cause mortality by 31 December 2015. Five-year relative survival ratios (RSRs) were calculated, and excess hazard ratios (EHRs) with 95% confidence intervals (CIs) were estimated using Poisson regression, adjusting for education, time since cancer diagnosis, and clinical factors including age at cancer diagnosis and International Federation of Gynecology and Obstetrics (FIGO) stage. Of the 2,845 included cases, hrHPV was detected in 2,293 (80.6%), and we observed 1,131 (39.8%) deaths during an average of 6.2 years follow-up. The majority of ICC cases were diagnosed at age 30-59 years (57.5%) and classified as stage IB (40.7%). hrHPV positivity was significantly associated with screen-detected tumors, young age, high education level, and early stage at diagnosis (p < 0.001). The 5-year RSR compared to the general female population was 0.74 (95% CI 0.72-0.76) for hrHPV-positive cases and 0.54 (95% CI 0.50-0.59) for hrHPV-negative cases, yielding a crude EHR of 0.45 (95% CI 0.38-0.52) and an adjusted EHR of 0.61 (95% CI 0.52-0.71). Risk of all-cause mortality as measured by EHR was consistently and statistically significantly lower for cases with hrHPV-positive tumors for each age group above 29 years and each FIGO stage above IA. The difference in prognosis by hrHPV status was highly robust, regardless of the clinical, histological, and educational characteristics of the cases. The main limitation was that, except for education, we were not able to adjust for lifestyle factors or other unmeasured confounders. CONCLUSIONS: In this study, women with hrHPV-positive cervical tumors had a substantially better prognosis than women with hrHPV-negative tumors. hrHPV appears to be a biomarker for better prognosis in cervical cancer independent of age, FIGO stage, and histological type, extending information from already established prognostic factors. The underlying biological mechanisms relating lack of detectable tumor hrHPV to considerably worse prognosis are not known and should be further investigated.

Human papillomavirus type 16 genomic variation in women with subsequent in situ or invasive cervical cancer: prospective population-based study.

BACKGROUND: HPV genomic variation may be involved in viral carcinogenesis. METHODS: In a national register-based nested case-control study, we retrieved archival smears from baseline cytologically normal women who later developed cancer in situ (CIS), squamous cervical cancer (SCC) or remained free of disease. These smears were previously HPV tested by PCR and HPV16 was the strongest risk factor. We now used the Illumina NextSeq platform to sequence HPV16 genomes in cervical smears from 242 women who later developed CIS/CIN3 (n = 134), SCC (n = 92) or remained healthy (n = 16). RESULTS: The median sequence depth per sample was high (11,288×). For 218/242 samples (>90%), we covered ≥80% of the complete HPV16 genome with sequencing median depths of >200×. We identified a wide range of unique isolates and 147 novel SNPs across the 218 samples. Most women (97%) had HPV16 lineage A infection, with the sublineages being A1 (66.1%), A2 (28.9%) and A4 (1.8%), respectively. The least variable gene was the E7 (3.4% variability), where 170/204 case women (83%) displayed a fully conserved sequence. There were no obvious differences by disease outcome (CIS or SCC). CONCLUSIONS: We found a high number of novel SNPs. The E7 gene was hypovariable both among women later developing CIN3/CIS, and SCC, respectively.

Nationwide comprehensive human papillomavirus (HPV) genotyping of invasive cervical cancer.

BACKGROUND: The Swedish National Cervical Screening Registry collects and evaluates comprehensive, nationwide health data to optimise organised cervical cancer prevention. Since all cervical cancer specimens are saved in biobanks, population-based data from the specimens should be available for analysis and linkage with other health information. METHODS: We identified all cervical cancers diagnosed in Sweden during 2002-2011 (4254 confirmed cases) and requested the tissue blocks to retrieve human papillomavirus (HPV) genotype data using general primer PCR with Luminex genotyping and real-time PCR targeting the E6/E7 regions of HPV16/18. RESULTS: We obtained blocks from 2932/4254 (69%) of cases. Valid HPV genotyping data was retrieved for 2850 cases (97%). The most common type was HPV16 (60%), followed by HPV18 (19%), HPV45 (7%), HPV31 (3%), HPV33 (2%), HPV52 (2%), HPV39 (1%), HPV70 (1%), HPV56 (1%), HPV35 (1%), HPV58 (1%) and HPV59 (1%). Ninety-six percent of all HPV-positive cases had a single infection. Eighty-nine cases were HPV-positive only when testing for the HPV16/18-E6/E7 region. CONCLUSIONS: We present one of the largest series of HPV-genotyped cervical cancers to date. The systematic collection of cervical cancer HPV genotyping data by the screening registry will facilitate prevention and monitoring of HPV type-specific disease burden.

Determinants of the presence of human papillomaviruses in the anal canal of Russian men.

Knowledge of determinants of anal human papillomavirus (HPV) infections among men is still limited as most of the studies are focused on high-risk populations and geographically narrowed. Such knowledge obtained in different populations is essential for better understanding of HPV natural history, transmission dynamics, and its role in the development and prevention of anogenital malignancies in different regions. Here we tested anal canal swab samples from 359 Russian heterosexual (323 human immunodeficiency virus [HIV]-negative and 27 HIV-positive, aged 18-67 years) men attending a sexually transmitted infection clinic 36 HPV types using a proficient Luminex assay. HPV-positivity in anal samples was common for 332 HIV-negative heterosexual men for overall HPV (15.7%, n = 52), oncogenic HPV (9.6%, n = 32), nononcogenic HPV (8.1%, n = 27), and multiple HPV infections (4.5%, n = 14). The most common anal HPV types were HPV16 (5.7%), HPV45, and HPV51 (1.8% each), HPV66, and HPV87 (1.8% each). No association was found with the number of lifetime sexual partners, age of participants at the time of the study, or their sexual debut. Although anal HPV positivity was more common among HIV-positive men, the current study provides additional evidence that anal HPV can be frequently detected in heterosexual HIV-negative men favoring further studies on transmission routes to discriminate between contamination and true HPV infection.

Long-term HPV type-specific risks of high-grade cervical intraepithelial lesions: a 14-year follow-up of a randomized primary HPV screening trial.

Quantitative knowledge of the long-term human papillomavirus (HPV) type-specific risks for high-grade cervical intraepithelial neoplasias Grades 2 and 3 (CIN2 and CIN3) is useful for estimating the effect of elimination of specific HPV types and clinical benefits of screening for specific HPV types. We estimated HPV type-specific risks for CIN2 and CIN3 using a randomized primary HPV screening trial followed up for 14.6 years using comprehensive, nationwide registers. Poisson regression estimated cumulative incidences, population attributable proportions (PAR) and incidence rate ratios (IRRs) of high-grade lesions by baseline HPV type, with censoring at date of first CIN2/3 or last registered cytology. Multivariate analysis adjusted for coinfections. IRRs were highest during the first screening round, but continued to be high throughout follow-up (IRRs for CIN3 associated with high-risk (HR) HPV positivity were 226.9, 49.3, 17.7 and 10.3 during the first, second and third screening round and for >9 years of follow-up, respectively). Increased long-term risks were found particularly for HPV Types 16, 18 and 31 and for CIN3+ risks. HPV16/18/31/33 had 14-year cumulative incidences for CIN3+ above 28%, HPV35/45/52/58 had 14 year risks between 14% and 18% and HPV39/51/56/59/66/68 had risks <10%. HPV16 contributed to the greatest proportion of CIN2+ (first round PAR 36%), followed by Types 31, 52, 45 and 58 (7-11%). HPV16/18/31/33/45/52/58 together contributed 73.9% of CIN2+ lesions and all HR types contributed 86.9%. In summary, we found substantial differences in risks for CIN2 and CIN3 between different oncogenic HPV types. These differences may be relevant for both clinical management and design of preventive strategies.

Long-term HPV type-specific risks for ASCUS and LSIL: a 14-year follow-up of a randomized primary HPV screening trial.

Human papillomavirus (HPV) infections result in a significant burden of low-grade cervical lesions. Between 1997 and 2000, our randomized trial of primary HPV screening enrolled 12,527 women participating in population-based screening. Women between 32 and 38 years of age (median: 34, interquartile range: 33-37) were randomized to HPV and cytology double testing (intervention arm, n = 6,257 enrolled, n = 5,888 followed-up) or to cytology, with samples frozen for future HPV testing (control arm, n = 6,270 enrolled, n = 5,795 followed-up). We estimated the HPV type-specific, long-term absolute risks (AR), and population attributable proportions (PAR) for cytological diagnoses of atypical squamous cells of undetermined significance (ASCUS) or low-grade squamous intraepithelial lesion (LSIL) and for histopathologically diagnosed cervical intraepithelial neoplasia grade 1 (CIN1). The women were followed using comprehensive, nationwide register-based follow-up. During a mean follow-up time of 11.07 years, 886 ASCUS and LSIL lesions were detected, 448 in the intervention arm and 438 in the control arm. Poisson regression estimated the incidence rate ratios (IRRs) of low-grade lesions by HPV type. The IRRs were strongly dependent on follow-up time. The IRRs for ASCUS/LSIL associated with high-risk HPV positivity were 18.6 (95% CI: 14.9-23.4) during the first screening round, 4.1 (95% CI: 2.8-6.2) during the second, 2.6 (95% CI: 1.7-4.1) during the third, and 1.1 (95% CI: 0.7-1.8) for >9 years of follow-up, with similar declines seen for the individual types. Type 16 contributed consistently to the greatest proportion of ASCUS, LSIL, and CIN1 risk in the population (first screening round PAR: ASCUS: 15.5% (95% CI: 9.7-21.9), LSIL: 14.7% (95% CI: 8.0-20.9), and CIN1: 13.4% (95% CI: 3.2-22.5)), followed by type 31 [8.4% (95% CI: 4.2-12.5) for ASCUS to 17.3% (95% CI: 6.8-26.6) for CIN1]. In summary, most ASCUS/LSIL lesions associated with HPV infection are caused by new HPV infections and most lesions are found during the first screening round.

Human papillomavirus type 197 is commonly present in skin tumors.

Non-melanoma skin cancers commonly contain Human Papillomavirus (HPV), but the types found have varied depending on the polymerase chain reaction (PCR) primer systems used. Whole genome amplified DNA (not amplified by any specific PCR primers) from 91 skin lesions [41 squamous cell skin carcinomas (SCCs), 8 keratoacanthomas, 22 actinic keratoses, 3 basal cell carcinomas and 17 SCCs in situ] were sequenced. All samples were sequenced both at 160 Mb and 1.8 Gb sequencing depth per sample. The sequences from 10 different HPVs in 47/91 specimens were found. Sequences represented four established HPV types (HPV types 16, 22, 120, 124), two previously known putative types (present in GenBank) and four previously unknown HPV sequences (new putative types). The most commonly detected virus was cloned, sequenced and designated as HPV197. Type-specific real-time PCR detected HPV197 in 34/91 specimens. For comparison, a pool of the same samples after general primer PCR amplification was also sequenced. This revealed 40 different HPVs, but only two HPV types were detected both with sequencing without prior PCR and with sequencing PCR amplicons, suggesting that sequencing without prior PCR gives a more unbiased representation of the HPVs present. In summary, it was found that HPV can be sequenced from most skin disease specimens and HPV197 appeared to be the most commonly present virus.

Global improvement in genotyping of human papillomavirus DNA: the 2011 HPV LabNet International Proficiency Study.

Accurate and internationally comparable human papillomavirus (HPV) DNA genotyping is essential for HPV vaccine research and for HPV surveillance. The HPV Laboratory Network (LabNet) has designed international proficiency studies that can be issued regularly and in a reproducible manner. The 2011 HPV genotyping proficiency panel contained 43 coded samples composed of purified plasmids of 16 HPV types (HPV6, -11, -16, -18, -31, -33, -35, -39, -45, -51, -52, -56, -58, -59, -66, -68a, and -68b) and 3 extraction controls. Tests that detected 50 IU of HPV16 and HPV18 and 500 genome equivalents for the other 14 HPV types in both single and multiple infections were considered proficient. Ninety-six laboratories worldwide submitted 134 data sets. Twenty-five different HPV genotyping assay methods were used, including the Linear Array, line blot/INNO-LiPA, PapilloCheck, and PCR Luminex assays. The major oncogenic HPV types, HPV16 and HPV18, were proficiently detected in 97.0% (113/116) and 87.0% (103/118) of the data sets, respectively. In 2011, 51 data sets (39%) were 100% proficient for the detection of at least one HPV type, and 37 data sets (28%) were proficient for all 16 HPV types; this was an improvement over the panel results from the 2008 and 2010 studies, when <25 data sets (23% and 19% for 2008 and 2010, respectively) were fully proficient. The improvement was also evident for the 54 laboratories that had also participated in the previous proficiency studies. In conclusion, a continuing global proficiency program has documented worldwide improvement in the comparability and reliability of HPV genotyping assay performances.

Human papillomavirus negative high grade cervical lesions and cancers: Suggested guidance for HPV testing quality assurance.

BACKGROUND: Some high-grade cervical lesions and cervical cancers (HSIL+) test negative for human papillomavirus (HPV). The HPV-negative fraction varies between 0.03 % and 15 % between different laboratories. Monitoring and extended re-analysis of HPV-negative HSIL+ could thus be helpful to monitor performance of HPV testing services. We aimed to a) provide a real-life example of a quality assurance (QA) program based on re-analysis of HPV-negative HSIL+ and b) develop international guidance for QA of HPV testing services based on standardized identification of apparently HPV-negative HSIL+ and extended re-analysis, either by the primary laboratory or by a national HPV reference laboratory (NRL). METHODS: There were 116 initially HPV-negative cervical specimens (31 histopathology specimens and 85 liquid-based cytology samples) sent to the Swedish HPV Reference Laboratory for re-testing. Based on the results, an international QA guidance was developed through an iterative consensus process. RESULT: Standard PCR testing detected HPV in 55.2 % (64/116) of initially "HPV-negative" samples. Whole genome sequencing of PCR-negative samples identified HPV in an additional 7 samples (overall 61.2 % HPV positivity). Reasons for failure to detect HPV in an HSIL+ lesion are listed and guidance to identify cases for extended re-testing, including which information should be included when referring samples to an NRL are presented. CONCLUSION: Monitoring the proportion of and reasons for failure to detect HPV in HSIL+ will help support high performance and quality improvement of HPV testing services. We encourage implementation of QA strategies based on re-analysis of "HPV negative" HSIL+ samples.