Impact of technology on cytology outcome in cervical cancer screening of young and older women

Time trends in the clinical management of cervical intraepithelial neoplasia grade 2: A Danish register-based study

INTRODUCTION

Active surveillance for cervical intraepithelial neoplasia grade 2 (CIN2) has been implemented recently in many countries, including the Nordic countries. In Denmark, the only eligibility criterion for active surveillance for CIN2 is that the woman should be of reproductive age. With this study, we aimed to evaluate clinical and socioeconomic characteristics in women with CIN2 managed by active surveillance or large loop excision of the transformation zone (LLETZ) and to evaluate temporal changes in the clinical management of CIN2.

MATERIAL AND METHODS

We conducted a Danish nationwide study using data from healthcare registries. All female residents aged 18-40 years, diagnosed with incident CIN2 from January 1, 1998, to February 29, 2020, were included. We collected data on age, index cytology result, year of CIN2 diagnosis, region of residence, civil status, HPV vaccination status, and socioeconomic position indicators. The variables were tabulated overall and by management group (active surveillance vs. LLETZ). To evaluate time trends, we used joinpoint regression to calculate the annual percentage change (APC), including 95% confidence intervals (CI).

RESULTS

Of the 27 536 women with CIN2 included, 12 500 (45.4%) underwent active surveillance, and 15 036 (54.6%) underwent a LLETZ. Women undergoing active surveillance were younger, more often HPV-vaccinated, and more likely to have a normal/low-grade index cytology result than women undergoing LLETZ. Socioeconomic position indicators did not differ. Over time, the proportion of women undergoing active surveillance increased from 21.7% in 2004 to 73.6% in 2019 (APC 9.7, 95% CI 8.1-11.4). The proportion of women undergoing active surveillance aged <30 declined over time (APC -2.2, 95% CI -2.9 to -1.5). The proportion of women with normal/low-grade index cytology increased slightly to 51.6% in 2019 (APC 0.8, 95% CI 0.4-1.3).

CONCLUSIONS

The use of active surveillance for CIN2 has increased over the past two decades in Denmark. Observed differences in characteristics between women undergoing active surveillance vs LLETZ are likely related to indications for clinical management.

The digital revolution in pathology: Towards a smarter approach to research and treatment

Artificial intelligence (AI) applications in oncology are at the forefront of transforming healthcare during the Fourth Industrial Revolution, driven by the digital data explosion. This review provides an accessible introduction to the field of AI, presenting a concise yet structured overview of the foundations of AI, including expert systems, classical machine learning, and deep learning, along with their contextual application in clinical research and healthcare. We delve into the current applications of AI in oncology, with a particular focus on diagnostic imaging and pathology. Numerous AI tools have already received regulatory approval, and more are under active development, bringing clear benefits but not without challenges. We discuss the importance of data security, the need for transparent and interpretable models, and the ethical considerations that must guide AI development in healthcare. By providing a perspective on the opportunities and challenges, this review aims to inform and guide researchers, clinicians, and policymakers in the adoption of AI in oncology.

Cervical cancer survivors and health care use: A Danish population-based register study

OBJECTIVE

To evaluate the impact of a cervical cancer (CC) diagnosis on use of health care and prescription drugs.

METHODS

This population-based register-study included Danish women aged 23-59 years and diagnosed with CC in 2001-2005. Women with a cervical screening outcome were used as comparison group. We obtained number of contacts to general practitioners (GPs), hospitals, psychologists/psychiatrists and defined daily doses (DDD) of analgesic/psychotropic prescription drugs. A difference-in-differences-design was used to estimate effect of a CC diagnosis on health-care use from five-year periods before and after the diagnosis/screening outcome.

RESULTS

In total, 926 women with CC and 1,004,759 women without cancer were included. In five years following the date of CC diagnosis, CC patients had increased their use of GPs with 8.6 (95% CI 4.8-12.4) contacts more than women in the comparison group, and with 4.12 (95% CI 3.99-4.25) more hospital contacts. In contrast, use of psychologists/psychiatrists was low and largely unaffected by the CC diagnosis. For use of prescription drugs, analgesics increased with 80 (95% CI 60-100) DDD more in CC patients than in comparison women, and for psychotropics with 304 (95% CI 261-347) DDD more.

CONCLUSIONS

A CC diagnosis was followed by an increase in use of GPs, hospitals, and analgesic/psychotropic prescription drugs, while use of psychologist/psychiatrist was largely unaffected. This pattern may indicate that pain/mental health concerns after CC either persisted or were alleviated by other means only.

Cervical cancer: Automation of Pap test screening

BACKGROUND

Cervical cancer progresses slowly, increasing the chance of early detection of pre-neoplastic lesions via Pap exam test and subsequently preventing deaths. However, the exam presents both false-negatives and false-positives results. Therefore, automatic methods (AMs) of reading the Pap test have been used to improve the quality control of the exam. We performed a literature review to evaluate the feasibility of implementing AMs in laboratories.

METHODS

This work reviewed scientific publications regarding automated cytology from the last 15 years. The terms used were "Papanicolaou test" and "Automated cytology screening" in Portuguese, English, and Spanish, in the three scientific databases (SCIELO, PUBMED, MEDLINE).

RESULTS

Of the resulting 787 articles, 34 were selected for a complete review, including three AMs: ThinPrep Imaging System, FocalPoint GS Imaging System and CytoProcessor. In total, 1 317 148 cytopathological slides were evaluated automatically, with 1 308 028 (99.3%) liquid-based cytology slides and 9120 (0.7%) conventional cytology smears. The AM diagnostic performances were statistically equal to or better than those of the manual method. AM use increased the detection of cellular abnormalities and reduced false-negatives. The average sample rejection rate was ≤3.5%.

CONCLUSION

AMs are relevant in quality control during the analytical phase of cervical cancer screening. This technology eliminates slide-handling steps and reduces the sample space, allowing professionals to focus on diagnostic interpretation while maintaining high-level care, which can reduce false-negatives. Further studies with conventional cytology are needed. The use of AM is still not so widespread in cytopathology laboratories.

High-grade cervical lesions after vaccination against human papillomavirus: A Danish cohort study

Introduction

It is pertinent to evaluate the impact of vaccination against human papillomavirus (HPV) in real life. The aim of the study was to evaluate the real‐life impact of HPV vaccination in the first birth cohort of Danish women offered free HPV vaccination as girls and invited to screening at the age of 23 years.

Material and methods

Women born in 1993 were offered free HPV vaccination at the age of 15 years but women born in 1983 have never been offered free HPV vaccination. We followed these two birth cohorts for 10 years from the age of 15 to after their first invitation to screening, and compared the risk of high‐grade cervical intraepithelial neoplasia (CIN). Data were obtained from Danish national health registers.

Results

Vaccination coverage was 91% in the 1993 birth cohort and <0.1% in the 1983 cohort. Screening coverage was close to 80% in both cohorts. CIN2+ was detected in 4% of the 15 748 screened women born in 1983 and in 3% of the 19 951 screened women born in 1993. The risk of high‐grade CIN was reduced by about 30% in the 1993 cohort compared with the 1983 cohort; for CIN2+ relative risk 0.74 (95% CI 0.66‐0.82) and for CIN3+ relative risk 0.68 (95% CI 0.58‐0.79).

Conclusions

This study investigated the real‐life impact of quadrivalent HPV vaccination by comparing a cohort of women offered HPV vaccination with a cohort of women not offered HPV vaccination. The observed decrease in the detection of high‐grade cervical lesions following HPV vaccination is in line with results from the randomized trials and has important implications for future cervical screening of HPV vaccinated cohorts.

Impact of HPV vaccination on outcome of cervical cytology screening in Denmark-A register-based cohort study

4vHPV vaccination has been tested in randomized controlled trials under almost ideal conditions, and studies of real-life use have compared outcome between vaccinated and unvaccinated women from the same birth cohort and mostly before screening age. Here we present the first-to our knowledge-evaluation of the impact of the 4vHPV vaccination in real life without selection bias in the reported data. The study has been carried out by comparing the results after first cervical screening between an HPV-vaccinated and an unvaccinated birth cohort, consisting of women born in Denmark in 1993 and 1983, respectively. Cytology data covering an 8-year period, from the age of 15 (age of HPV-vaccination) to age 23 (age of invitation to first cervical screening), were retrieved from the Danish National Pathology Register. Abnormal cytology, defined as atypical squamous cell of undetermined significance and worse (ASCUS+) was detected in 9.4% of women born in 1993 as compared with 9.0% of women born in 1983; RR = 1.04 (95% CI 0.96-1.12), p = .29. Detection of high-grade squamous intraepithelial lesion (HSIL) was statistically significantly lower in the 1993 than in the 1983 cohort, RR = 0.6 (95% CI 0.5-0.7), p < .0001, while the opposite pattern was seen for ASCUS RR = 1.4 (95% CI 1.2-1.6), p < .0001. The decrease in HSIL means that more women can be spared referral for colposcopy and biopsy. The increase of ASCUS could be explained by transition from conventional to liquid-based cytology, but this observation requires further monitoring.

Cervical cancer incidence after normal cytological sample in routine screening using SurePath, ThinPrep, and conventional cytology: population based study

Objective To compare the cumulative incidence of cervical cancer diagnosed within 72 months after a normal screening sample between conventional cytology and liquid based cytology tests SurePath and ThinPrep.Design Retrospective population based cohort study.Setting Nationwide network and registry of histo- and cytopathology in the Netherlands (PALGA), January 2000 to March 2013.Population Women with 5 924 474 normal screening samples (23 833 123 person years).Exposure Use of SurePath or ThinPrep versus conventional cytology as screening test.Main outcome measure 72 month cumulative incidence of invasive cervical cancer after a normal screening sample for each screening test. Cox regression analyses assessed the hazard ratios, adjusted for calendar time, age, screening history, and socioeconomic status and including laboratories as random effects.Results The 72 month cumulative cancer incidence was 58.5 (95% confidence interval 54.6 to 62.7) per 100 000 normal conventional cytology samples, compared with 66.8 (56.7 to 78.7) for ThinPrep and 44.6 (37.8 to 52.6) for SurePath. Compared with conventional cytology, the hazard of invasive cancer was 19% lower (hazard ratio 0.81, 95% confidence interval 0.66 to 0.99) for SurePath, mainly caused by a 27% lower hazard (0.73, 0.57 to 0.93) of a clinically detected cancer. For ThinPrep, the hazard was on average 15% higher (hazard ratio 1.15, 0.95 to 1.38), mainly caused by a 56% higher hazard of a screen detected cancer (1.56, 1.17 to 2.08).Conclusions These findings should provoke reconsideration of the assumed similarity in sensitivity to detect progressive cervical intraepithelial neoplasia between different types of liquid based cytology and conventional cytology.

Cervical cancer screening in Greenland, 1997-2011: Screening coverage and trends in the incidence of high-grade cervical lesions

OBJECTIVE

In spite of the high incidence of cervical cancer in Greenland, no assessment has been made of the impact of organized cervical screening, introduced in 1998, in relation to occurrence of high-grade cervical lesions. The objectives of the present study were to estimate coverage of the screening program and to examine possible changes in cervical intraepithelial neoplasia (CIN3) incidence in Greenland during 1997-2011 according to calendar period and age.

METHODS

Using nationwide registries, we calculated age-standardized incidence rates for all women born and living in Greenland. To investigate whether possible variation in the incidence of CIN3 were related to differences in screening coverage, we further estimated relative risks of CIN3 within two years of screening among women who participated in the screening program using log-linear binomial regression.

RESULTS

Coverage of the screening program was low during 1997-2011 with the highest level of 54% observed in 2011. Peaks in CIN3 incidence of around 300 per 100,000 person-years were observed in 1999 and between 2009 and 2011, while the incidence was lower of approximately 100 per 100,000 person-years between 2000 and 2008. During 2009-2011, the highest incidence was found among women aged 25-34 years. Similar patterns of CIN3 risk according to calendar period and age groups were observed among screened women.

CONCLUSIONS

The great variations in CIN3 incidence and low screening coverage observed during 1997-2011 suggest that improvements in the Greenlandic screening program are warranted.

Comparing SurePath, ThinPrep, and conventional cytology as primary test method: SurePath is associated with increased CIN II+ detection rates

Purpose

Within the last decade, SurePath and ThinPrep [both liquid-based cytology (LBC) tests] have replaced conventional cytology (CC) as primary test method in cervical cancer screening programs of multiple countries. The aim of our study was to examine the effect in the Dutch screening program.

Methods

All primary smears taken within this program from 2000 to 2011 were analyzed using the nationwide registry of histo- and cytopathology (PALGA) with a follow-up until March 2013. The percentage of smears classified as borderline/mildly dyskaryotic (BMD) and >BMD as well as CIN and cervical cancer detection rates were compared between SurePath and ThinPrep versus CC by logistic regression analyses (adjusted for age, screen region, socioeconomic status, and calendar time).

Results

We included 3,118,685 CC, 1,313,731 SurePath, and 1,584,587 ThinPrep smears. Using SurePath resulted in an increased rate of primary smears classified as >BMD [odds ratio (OR) = 1.12 (95% confidence interval (CI) 1.09–1.16)]. CIN I and II⁺ detection rates increased by 14 % [OR = 1.14 (95% CI 1.08–1.20)] and 8 % [OR = 1.08 (95% CI 1.05–1.12)]. Cervical cancer detection rates were unaffected. Implementing ThinPrep did not result in major alterations of the cytological classification of smears, and it did not affect CIN detection rates. While not significant, cervical cancer detection rates were lower [OR = 0.87 (95% CI 0.75–1.01)].

Conclusions

The impact of replacing CC by LBC as primary test method depends on the type of LBC test used. Only the use of SurePath was associated with increased CIN II⁺ detection, although it simultaneously increased the detection of CIN I.

Cervical histology after routine ThinPrep or SurePath liquid-based cytology and computer-assisted reading in Denmark

Background:

We compared the sensitivity and specificity of liquid-based cytology (LBC) and computer-assisted reading for SurePath/FocalPoint and ThinPrep with those of manually read conventional cytology in routine cervical screening in four Danish laboratories.

Methods:

Using data from five nationwide registers, technological phases were identified by slide preparation, reading technique, and triage of borderline cytology. Trends in the detection of cervical intraepithelial neoplasia (CIN) were an indicator of the technology's relative sensitivity, and trends in false-positive tests an indicator of relative specificity.

Results:

At 23–29 years, SurePath/FocalPoint statistically significantly increased the detection of ⩾CIN3 by 85% compared with manually read conventional cytology. The 11% increase with ThinPrep was not significant. At 30–44 years, the increase with SurePath/FocalPoint was 58% the 16% increase with ThinPrep was not significant. At 45–59 years, both technologies led to nonsignificant decreases in the detection. SurePath/FocalPoint doubled the frequency of false-positive tests at any age. With ThinPrep, these proportions remained the same at 23–29 years, but decreased by two-thirds at 45–59 years. In a fourth laboratory with continuous use of manually read conventional cytology, no such trends were seen.

Conclusions:

The sensitivity and specificity of modern LBC and computer-assisted reading technologies may be brand- and age-dependent.

Exploring the trend of increased cervical intraepithelial neoplasia detection rates in the Netherlands

OBJECTIVE

Over the last decade, cervical intraepithelial neoplasia (CIN) detection has increased in the Netherlands. We investigated the underlying mechanism by quantifying the increase, and analyzing patterns of CIN and cervical cancer detection over time.

METHODS

We observed annual CIN and cervical cancer detection rates (DRs) per 10,000 primary smears within the Dutch screening programme for 2000-2011. Joinpoint analyses were performed to determine changes in time trends, logistic regression analyses to assess the relative risk of calendar time on histological outcomes, adjusted for demographic factors and type of primary cytology test used.

RESULTS

Trends of increased detection occurred for all CIN grades (ie. DRs increased from 17.8 to 36.1, from 21.0 to 35.5, and from 43.4 to 64.6 for CIN I, II, and III from 2003 to 2009). After adjusting for demographic factors, DRs were still 2.11 (95% confidence interval (CI): 1.95, 2.29), 1.79 (95% CI: 1.66, 1.92) and 1.59 (95% CI: 1.50, 1.67) times larger in 2009. When also adjusting for the type of cytology test, DRs were 1.90 (95% CI: 1.62, 2.22), 1.48 (95% CI: 1.22, 1.79) and 1.55 (95% CI: 1.39, 1.73) times larger. No trends in cervical cancer DRs were found.

CONCLUSIONS

The implementation of liquid-based cytology contributed to the CIN increase. If some of these extra detected CIN are regressive this leads to overdiagnosis. Other factors, such as an increased cervical cancer risk, and implementation of imaging-assisted reading, could also have contributed.

Cervical cancer screening in the Faroe Islands

BACKGROUND

The Faroe Islands have had nationally organised cervical cancer screening since 1995. Women aged 25-60 years are invited every third year. Participation is free of charge. Although several European overviews on cervical screening are available, none have included the Faroe Islands. Our aim was to provide the first description of cervical cancer screening, and to determine the screening history of women diagnosed with cervical cancer in the Faroe Islands.

MATERIAL AND METHODS

Screening data from 1996 to 2012 were obtained from the Diagnostic Centre at the National Hospital of the Faroe Islands. They included information on cytology and HPV testing whereas information on histology was not registered consistently. Process indicators were calculated, including coverage rate, excess smears, proportion of abnormal cytological samples, and frequency of HPV testing. Data on cervical cancer cases were obtained from the Faroese Ministry of Health Affairs. The analysis of the screening history was undertaken for cases diagnosed in 2000-2010.

RESULTS

A total of 52 457 samples were taken in 1996-2012. Coverage varied between 67% and 81% and was 71% in 2012. Excess smears decreased after 1999. At present, 7.0% of samples have abnormal cytology. Of all ASCUS samples, 76-95% were tested for HPV. A total of 58% of women diagnosed with cervical cancer did not participate in screening prior to their diagnosis, and 32% had normal cytology in the previous four years.

CONCLUSION

Despite the difficult geographical setting, the organised cervical cancer screening programme in the Faroe Islands has achieved a relatively high coverage rate. Nevertheless, challenges, e.g. consistent histology registration and sending reminders, still exist.

Cervical cancer screening at crossroads

Cervical screening has been one of the most successful public health prevention programmes. For 50 years, cytology formed the basis for screening, and detected cervical intraepithelial lesions (CIN) were treated surgically to prevent progression to cancer. In a high-risk country as Denmark, screening decreased the incidence of cervical cancer from 34 to 11 per 100,000, age-standardized rate (World Standard Population). Screening is, however, also expensive; Denmark (population: 5.6 million) undertakes close to half a million tests per year, and has 6-8 CIN-treated women for each prevented cancer case. The discovery of human papillomavirus (HPV) as the cause of cervical cancer dramatically changed perspectives for disease control. Screening with HPV testing was launched around 1990, and preventive HPV vaccination was licensed in 2006. Long-term randomized controlled trials (RCT) demonstrated that HPV testing provides better protection against cervical cancer than cytology, but it requires extra repeated testing. HPV vaccination RCTs, furthermore, have proved that HPV vaccination protects against vaccine-type high-grade CIN in women vaccinated prior to sexual activity, but less so in women vaccinated later. The challenge now is therefore to find an algorithm for screening of a heterogeneous population including non-vaccinated women; women vaccinated prior to start of sexual activity; and women vaccinated later.