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.

Validation of the cobas 6800 human papillomavirus test in primary cervical screening

Evaluation of Human Papillomavirus (HPV) testing systems suitable for large-scale organized cervical screening programs is required. We evaluated the cobas 6800 HPV test system for detection of cervical intraepithelial neoplasia grade 3 or worse (CIN3+) when nested in an organized primary HPV screening program, using the cobas 4800 test as comparator. The Karolinska University Hospital Cervical Cytology Biobank, containing frozen cervical samples from >700,000 women participating in organized cervical screening, was linked to the Swedish national cervical screening registry to identify 470 stored cervical samples taken <180 days before histopathological diagnosis of CIN3+. Two controls per case, with no abnormal results for 2 screening rounds, matched for age and sampling time were also retrieved. Aliquots from 1406 women were retrieved and re-tested on the cobas 4800 system and tested on the cobas 6800 system. There was high reproducibility between the original cobas 4800 HPV test results, and the cobas 4800 HPV re-testing performed on the samples retrieved from biobank storage. 462/464 biobanked samples from women with CIN3+ tested HPV-positive on the cobas 6800 system, corresponding to a relative sensitivity of 99.6%. 925/932 biobanked samples from control women tested HPV-negative on the cobas 6800 platform, corresponding to a relative specificity of 99.2%. By conventional criteria, the cobas 6800 was non-inferior both regarding relative sensitivity of >90% (non-inferiority p-value <0.0001) and relative specificity of >98% (non-inferiority p-value 0.006). We conclude that the cobas 6800 HPV test system had similar, high performance as the cobas 4800 such, when evaluated using cervical samples taken before CIN3+ in a real-life primary HPV screening program.

Identification of the endosymbionts from Sulla spinosissima growing in a lead mine tailings in Eastern Morocco as Mesorhizobium camelthorni sv. aridi

AIMS

To identify the bacteria nodulating Sulla spinosissima growing profusely in a lead and zinc mine tailings in Eastern Morocco.

METHODS AND RESULTS

In all, 32 rhizobial cultures, isolated from root nodules of S. spinosissima growing in soils of the mining site, were tolerant to different heavy metals. The ERIC-polymerase chain reaction (PCR) fingerprinting analysis clustered the isolates into seven different groups, and the analysis of the 16S rRNA sequences of four selected representative strains, showed they were related to different species of the genus Mesorhizobium. The atpD, glnII and recA housekeeping genes analysis confirmed the affiliation of the four representative strains to Mesorhizobium camelthorni CCNWXJ40-4^T , with similarity percentages varying from 96·30 to 98·30%. The sequences of the nifH gene had 97·33-97·78% similarities with that of M. camelthorni CCNWXJ40-4^T ; however, the nodC phylogeny of the four strains diverged from the type and other reference strains of M. camelthorni and formed a separated cluster. The four strains nodulate also Astragalus gombiformis and A. armatus but did not nodulate A. boeticus, Vachellia gummifera, Prosopis chilensis, Cicer arietinum, Lens culinaris, Medicago truncatula, Lupinus luteus or Phaseolus vulgaris.

CONCLUSIONS

Based on similarities of the nodC symbiotic gene and differences in the host range, the strains isolated from S. spinosissima growing in soils of the Sidi Boubker mining site may form a different symbiovar within Mesorhizobium for which the name aridi is proposed.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this work, we show that strains of M. camelthorni species nodulating S. spinosissima in the arid area of Eastern Morocco constitute a distinct phylogenetic clade of nodulation genes; we named symbiovar aridi, which encompasses also mesorhizobia from other Mediterranean desert legumes.

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.

HPV-mRNA and HPV-DNA detection in samples taken up to seven years before severe dysplasia of cervix uteri

Randomized clinical trials using human papillomavirus (HPV) DNA testing have found increased protection against cervical cancer and HPV-based screening is globally recommended for women ≥30 years of age. HPV-mRNA is a promising alternative target for cervical screening tests, but assessing equivalence requires longitudinal evaluation over at least the length of a screening interval. Our aim is to analyze the longitudinal sensitivity of HPV-mRNA and HPV-DNA in cervical samples taken up to 7 years before severe cervical intraepithelial neoplasia or worse (CIN3+). From a population-based cohort of 95,023 women in Sweden, cervical samples were frozen at -80°C between May 2007 and January 2012. Registry linkages identified that 1,204 of these women had CIN3+ 4 months to 7 years after enrolment. Baseline samples were analyzed for HPV-mRNA (Aptima, Hologic) and for HPV-DNA (Cobas 4800, Roche) and results from both tests obtained for 1,172 women. For both women <30 and ≥ 30 years, HPV-mRNA had similar sensitivity for CIN3+ as HPV-DNA (p = 0.0217 and p = 0.0123 in noninferiority testing for at least 90% relative sensitivity, respectively). Among women ≥30 years, the longitudinal sensitivities for CIN3+ occurring 5-7 years later were comparable [76.3% (95% CI: 65.8%-84.3%) and 82.5% (95% CI: 72.6%-89.4%)] as were the longitudinal negative predictive values for absence of CIN3+ [99.97% (95% CI: 99.95-99.98) and 99.98% (95% CI: 99.96-99.99)], for the HPV-mRNA and HPV-DNA test. In conclusion, HPV-mRNA testing has similar longitudinal sensitivity as HPV-DNA, implying that HPV-mRNA testing can safely be used for cervical screening.

Randomised healthcare policy evaluation of organised primary human papillomavirus screening of women aged 56-60

OBJECTIVE

The aim of this research is to implement and reliably evaluate primary human papillomavirus (HPV) screening in an established and routinely running organised, large-scale population-based screening programme.

PARTICIPANTS

Resident women in the Stockholm/Gotland region of Sweden, aged 56-60 years were randomised to either (1) screening with cervical cytology, with HPV test in triage of low-grade cytological abnormalities (old policy) or (2) screening with HPV testing, with cytology in triage of HPV positives (new policy).

OUTCOME

The primary evaluation was the detection rate of cervical intraepithelial neoplasia grade 2 or worse (CIN2+).

RESULTS

During January 2012-May 2014, the organised screening programme sent 42 752 blinded invitations with a prebooked appointment time to the women in the target age group. 7325 women attended in the HPV policy arm and 7438 women attended in the cytology arm. In the new policy, the population HPV prevalence was 5.5%, using an accredited HPV test (Cobas 4800). HPV16 prevalence was 1.0% (73/7325) and HPV18 prevalence was 0.3% (22/7325). In the HPV policy arm, 78/405 (19%) HPV-positive women were also cytology positive. There were 19 cases of CIN2+ in histopathology, all among women who were both HPV positive and cytology positive. The positive predictive value for CIN2+ in this group was 33.3% (19/57). In the cytology policy, 153 women were cytology positive and there were 18 cases of CIN2+ in histopathology. Both the total number of cervical biopsies and the number of cervical biopsies with benign histopathology were much lower in thepositive predictive value policy (49 benign, 87 total vs 105 benign, 132 total).

CONCLUSION

Primary HPV screening had a similar detection rate for CIN2+ as cytology-based screening, already before follow-up of HPV-positive, cytology-negative women with new HPV test and referral of women with persistence.

TRIAL REGISTRATION NUMBER

NCT01511328.

Laboratory audit as part of the quality assessment of a primary HPV-screening program

BACKGROUND

As primary HPV screening programs are rolled out, methods are needed for routine quality assurance of HPV laboratory analyzes.

OBJECTIVE

To explore the use of similar design for audit as currently used in cytology-based screening, to estimate the clinical sensitivity to identify women at risk for CIN 3 or worse (CIN3+).

STUDY DESIGN

Population-based cohort study conducted within the cervical screening program in Stockholm, Sweden, in 2011-2012. All women with histopathologically confirmed CIN3+ in the following two years were identified by registry analysis. Primary HPV and cytology screening results were collected. For women who had not been HPV tested, biobanked cytology samples were HPV-tested. If the original HPV result had been negative, the sample and subsequent biopsies were analyzed with broad HPV typing (general primer PCR and Luminex).

RESULTS

154 women had a biobanked prediagnostic cytology sample taken up to 2 years before a histopathologically confirmed CIN3+. The high-risk HPV-positivity was 97% (148/154 women), whereas 143/154 (94%) women had had a cytological abnormality. Among the six HPV-negative samples, one sample was HPV 33 positive in repeat testing whereas the other five cases were HPV-negative also on repeat testing, but HPV-positive in the subsequent tumor tissue.

CONCLUSIONS

A sensitivity of the HPV test that is higher than the sensitivity of cytology suggests adequate quality of the testing. Regular audits of clinical sensitivity, similar to those of cytology-based screening, should be used also in HPV-based screening programs, in order to continuously monitor the performance of the analyzes.