Results of delayed triage by HPV testing and cytology in the Norwegian Cervical Cancer Screening Programme

Review of triage strategies for atypical squamous cells of undetermined significance among young women

In the present study we reviewed the existing literature regarding management approaches for ASC-US and highlight their pros and cons. The ASC-US entity emerged from Bethesda classification 2001. We conducted this review using search words ASC-US triage, ASC-US management in young women, triage tests for ASC-US, and ASC-US outcome from the English literature. We included different cervical cancer policies (American, European and for WHO) and research articles published on ASC-US in young women from the year 2001. We searched in Google Scholar, PubMed, MEDLINE (NCBI) library, Embase (Elsevier), Wiley online library as well as Cochrane library. We defined young women as aged 30 years and below. We identified 52 articles which focused on management approaches of ASC-US, seven articles focused on young women aged <30 years. Five of these articles combined ASC-US with low-grade squamous intraepithelial lesions (ASC-US/LSIL) while only two addressed ASC-US as a standalone entity. The limited number of articles restricts the evidence base supporting the adoption of triage strategies. There is yet, no consensus in the literature regarding the management of ASC-US, more so in young women below the age of 30 years. Researchers, however, agree on a few aspects, which include the necessity for applying a conservative strategy for managing ASC-US in young women, avoiding direct referral for colposcopy at the initial detection of ASC-US, and avoiding the use of human papillomavirus (HPV) testing on young women (unless living with HIV). Newer techniques such as HPV E6/E7 messenger RNA (mRNA), and dual staining p16/ki-67, may serve as better triage to identify cases of HPV persistence and integration which may subsequently lead to preinvasive or invasive lesions.

Management of low-grade cervical cytology in young women. Cohort study from Denmark

OBJECTIVE

Cytology findings of atypical squamous cells of unknown significance (ASCUS) or low-grade squamous intraepithelial lesion (LSIL) are common among women under 30, but evidence on best management strategy is insufficient. We therefore investigated how different management strategies used in Denmark influenced biopsy rates and detection of cervical intraepithelial neoplasia (CIN).

METHODS

Register-based cohort study including Danish women aged less than 30 years and born 1980-95, with ASCUS/LSIL as their first abnormal cervical cytology in 2008-16. Rates and relative risks (RR) of biopsy and detection of CIN3+, CIN2 and < CIN2 during two years follow-up were compared between women referred directly to colposcopy after ASCUS/LSIL or undergoing additional testing, including mRNA or DNA test for high risk HPV or repeat cytology.

RESULTS

19,946 women with ASCUS and 19,825 with LSIL were included in the study of whom 92% had adequate information about follow-up. Among women referred directly to biopsy, CIN3+ was detected among 21%, CIN2 in 17%, while 62% had < CIN2. Repeating cytology after 6 months reduced the biopsy rate to 44% of which 53% had < CIN2. Biopsy rates with HPV test were 67% for DNA test, 77% with 14-type mRNA test and 58% with 5-type mRNA test. The detection of CIN3+ was somewhat higher, between 13% and 14% for the three HPV tests vs. 11% with repeat cytology. However, the detection of < CIN2 (not indicating treatment) also increased with RR 2.11 (95% CI 2.01-2.21) for 14-type mRNA test, 1.35 (95% CI 1.29-1.41) for 5-type mRNA test, and 1.86 (95% CI 1.76-1.97) with HPV DNA test.

CONCLUSIONS

The choice of management strategy influences both the detection rate for severe lesions (CIN3+) and the proportion of women followed up for potentially insignificant findings.

High-risk Human Papillomavirus Testing in Young Japanese Women with Atypical Squamous Cells of Undetermined Significance

Introduction:

The mortality due to uterine cervical cancer has been gradually increasing in women under 40 years of age (U40) in Japan. We investigated the effect of high-risk human papillomavirus (HR-HPV) on U40 subjects without any overt cytological abnormalities.

Materials and Methods:

We retrospectively examined the clinical data, including the findings of a cobas 4800 HPV test that was approved in Japan in 2013 to triage women with atypical squamous cells of undetermined significance (ASC-US) and a histological examination in 589 Japanese women.

Results:

The overall prevalence rate of HR-HPV was 34.5%. Biopsy-confirmed cervical intraepithelial neoplasia (CIN) 2, or worse (CIN2+) was identified in 45.1% (23/51) of HR-HPV-positive women with ASC-US, who underwent colposcopy immediately. The mean period from the HPV test to the diagnosis of CIN2+ was 3.7 months. CIN2+ was more common (69.6%) in U40 patients. The rates of single or multiple infections of HPV-16, HPV-18, and 12 other HR-HPV (31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68) in CIN2+ U40 patients were 31.3%, 0%, and 81.3%, respectively. The relative risk for CIN 2+ among U40 women with HPV-16 was not significantly different from that of the patients with infection of any of the 12 other HR-HPVs.

Conclusion:

The results of this study suggest that the 12 other HR-HPVs have a potential to generate high-grade cervical lesions among young women, and the examination rate of colposcopy should be increased.

Recent increase in incidence of cervical precancerous lesions in Norway: Nationwide study from 1992 to 2016

We analysed patterns in the incidence of cervical intraepithelial neoplasia grades 2 and 3 (CIN2, CIN3) and adenocarcinoma in situ (AIS) by age and histology in 1992–2016 in Norway and described changes in screening tests. Incident cases of CIN2, CIN3, AIS and cervical cancer were identified in the Cancer Registry of Norway, as were all women with at least one screening test. The annual percentage change statistic was used to assess point estimates and changes in age‐specific and age‐standardised incidence rates (IR). Women aged 25–29 years had the highest incidence of cervical precancerous lesions (CIN2: 192.9/10, CIN3: 737.2/10, AIS: 32.5/10⁵ in 2016). The IR of CIN2 increased for all screening ages (25–69 years) from 3.6% to 6.7% per year. CIN3 incidence increased by 1.6% (95% confidence interval [CI] 0.6–2.6) annually. A steep increase in AIS incidence was observed in all age groups (7.1% per year, 95% CI 5.3–8.8). Changes in screening tests and the histological verification of cervical precancerous lesions alone cannot explain the steady increase in incidence we observed over the 25‐year study period, and increased exposure to human papillomavirus (HPV) likely plays a role. Age‐appropriate treatment of screening‐detected cervical precancerous lesions is needed for effective cervical cancer control while avoiding overtreatment and related health risks. In order to perform an appropriate harm‐benefit evaluation of cervical cancer control efforts, detailed information on screening technology and background risks, including HPV vaccination status, is needed to create optimal public health policy.

What's new?

In Norway, cervical cancer screening coverage has held steady around 65–68%, while incidence of cervical precancerous lesions has increased. Here, the authors analysed changes in incidence of cervical intraepithelial neoplasias grades 2 and 3 (CIN2 and 3) and adenocarcinoma in situ (AIS). They observed period effects of the same magnitude for all three, indicating that changes in the screening test accounts for part of the increase. Another likely cause, they report, is increased exposure to HPV. Public health policy, they conclude, should consider detailed information on screening technology and background risks, including HPV vaccination status.

Psychological effect of cervical cancer screening when changing primary screening method from cytology to high-risk human papilloma virus testing

From 2015, Norway has implemented high‐risk human papilloma virus (hrHPV) testing in primary screening for cervical cancer. Women aged 34–69 years, living in four counties, have been pseudo‐randomly assigned (1:1 randomization) to either hrHPV testing every 5 years (followed by cytology if hrHPV is positive), or cytology testing every 3 years (followed by hrHPV testing if low‐grade cytology is detected). We compared anxiety and depression scores among participants by screening arm and results. In total, 1,008 women answered a structured questionnaire that included the validated Patient Health Questionnaire‐4 (PHQ‐4). The Relative Risk Ratio (RRR) of mild vs. normal anxiety and depression scores, and moderate/severe vs. normal anxiety and depression scores, were estimated by multinomial logistic regression with 95% confidence intervals (95% CIs). Compared to women who were screened with cytology, women randomized to hrHPV testing were not more likely to have mild anxiety and depression scores (RRR 0.96, CI 0.70–1.31) nor more likely to have moderate/severe anxiety and depression scores (RRR 1.14, CI 0.65–2.02). Women with five different combinations of abnormal screening test results were not more likely to have mild or moderate/severe vs. normal anxiety and depression scores than women with normal screening results. The likelihood of having abnormal long‐term (4–24 months after the screening) anxiety or depression scores among women 34 years and older was not affected by screening method or screening results. The results of our study suggest that a change to hrHPV testing in primary screening would not increase psychological distress among participants.

What's new?

Norway is one of the first countries to implement high‐risk human papilloma virus (hrHPV) testing in primary cervical‐cancer screening. Does this newer type of testing impact the emotional well‐being of patients? In this study, the authors found no significant difference in either anxiety or depression scores between the viral‐screening arm and standard cytology screening. These findings could be useful for other countries considering implementing hrHPV testing, and are reassuring for the ongoing implementation process in Norway.

Cervical Cancer Screening Programs in Europe: The Transition Towards HPV Vaccination and Population-Based HPV Testing

Cervical cancer is the fourth most frequently occurring cancer in women around the world and can affect them during their reproductive years. Since the development of the Papanicolaou (Pap) test, screening has been essential in identifying cervical cancer at a treatable stage. With the identification of the human papillomavirus (HPV) as the causative agent of essentially all cervical cancer cases, HPV molecular screening tests and HPV vaccines for primary prevention against the virus have been developed. Accordingly, comparative studies were designed to assess the performance of cervical cancer screening methods in order to devise the best screening strategy possible. This review critically assesses the current cervical cancer screening methods as well as the implementation of HPV vaccination in Europe. The most recent European Guidelines and recommendations for organized population-based programs with HPV testing as the primary screening method are also presented. Lastly, the current landscape of cervical cancer screening programs is assessed for both European Union member states and some associated countries, in regard to the transition towards population-based screening programs with primary HPV testing.

Human papillomavirus type specific risk of progression and remission during long-term follow-up of equivocal and low-grade HPV-positive cervical smears

The prevalence of clinically relevant HPV types and their specific risk for progression and regression in women with atypical squamous cells of uncertain significance (ASCUS) and low-grade squamous intraepithelial lesions (LSIL) were studied in a routine screening population. A 4-year cohort of women (n = 820) with ASCUS/LSIL and a positive HPV test in triage were followed for 6-9 years. The progression risks for CIN2+/CIN3+ were determined for single (71.2%) and multiple HPV infections (28.8%). The CIN2+ progression risk for all HPV 16, all HPV 35, single HPV 16 and single HPV 35 infections were 65.3% (95% CI: 59.6-71.0), 64.4% (95% CI: 50.4-78.4), 63.8% (95% CI: 56.2-71.4) and 73.7% (95% CI: 53.9-93.5), respectively. Based on CIN2+ progression risks four main groups were defined; the HPV 16 group, the HPV 31/33/35 group, the HPV 18/45/51/52 group and the HPV 39/56/58/59/66/68 group with progression risks of 65.3% (95% CI: 59.6-71.0), 62.1% (95% CI: 54.8-69.4), 52.6 (95% CI: 45.9-59.3) and 39.5 (95% CI: 33.0-46.0), respectively. In multivariate analyses, women in the age group 40-49 years had an increased risk of CIN2+ progression. As for CIN3+, HPV 16 had a higher progression risk than other HPV risk groups (p < 0.05). In multiple infections only HPV 16 had a significant additive CIN3+ progression risk (p < 0.05) as compared to other HPV risk groups. In summary, HPV types 16 and 35, including the HPV risk group 31/33/35, had a similar CIN2+ progression risk, but only HPV 16 had a higher risk for CIN3+ progression.

An overview of cervical cancer epidemiology and prevention in Scandinavia

New technologies such as human papillomavirus (HPV) testing and vaccination necessitate comprehensive policy analyses to optimize cervical cancer prevention. To inform future Scandinavian-specific policy analyses, we aimed to provide an overview of cervical cancer epidemiology and existing prevention efforts in Denmark, Norway and Sweden. We compiled and summarized data on current prevention strategies, population demography and epidemiology (for example, age-specific HPV prevalence and cervical cancer incidence over time) for each Scandinavian country by reviewing published literature and official guidelines, performing registry-based analyses using primary data and having discussions with experts in each country. In Scandinavia, opportunistic screening occurred as early as the 1950s and by 1996, all countries had implemented nationwide organized cytology-based screening. Prior to implementation of widespread screening and during 1960-66, cervical cancer incidence was considerably higher in Denmark than in Norway and Sweden. Decades of cytology-based screening later (i.e. 2010-2014), cervical cancer incidence has been considerably reduced and has converged across the countries since the 1960s, although it still remains lowest in Sweden. Generally, Scandinavian countries face similar cervical cancer burdens and utilize similar prevention approaches; however, important differences remain. Future policy analyses will need to evaluate whether these differences warrant differential prevention policies or whether efforts can be streamlined across Scandinavia.