Alternative technologies in cervical cancer screening: a randomised evaluation trial

Lower incidence of vaginal cancer after cervical human papillomavirus screening - long-term follow-up of Finnish randomized screening trial

OBJECTIVE

Around 70% of vaginal cancers and 40-50% of vulvar cancers are attributable to human papillomavirus (HPV). Globally the burden of these diseases is estimated to grow due to the increasing HPV prevalence and rapidly aging global population. We aimed to examine if HPV screening for cervical cancer has an additional beneficial effect in preventing vaginal and vulvar cancers. To assess this, we used long-term follow-up data from the Finnish randomized HPV screening trial.

METHODS

Between 2003 and 2008, over 236,000 women were individually randomized (1:1) to primary HPV or cytology screening in Southern Finland. We followed this cohort up to the year 2020. To compare the study arms, we calculated site-specific and pooled incidence rate ratios (IRRs) and mortality rate ratios (MRRs) for vaginal and vulvar cancers using Poisson regression.

RESULTS

During 3,5 million person-years of follow-up, the IRR for vaginal cancer in the HPV arm compared to the cytology arm was 0.40 (95% CI 0.17-0.88) and the corresponding MRR was 0.74 (95% 0.21-2.24). The corresponding IRR for vulvar cancer was 0.73 (95% 0.50-1.08) and the MRR was 0.64 (95% 0.23-1.62). The pooled IRR was 0.67 (95% 0.47 ̶ 0.95) and MRR 0.67 (95% 0.31 ̶ 1.37).

CONCLUSION

We found lower incidence of vaginal cancers with HPV screening compared to cytology screening. To validate our results, we recommend analyzing data on vaginal and vulvar cancers also from other HPV screening studies.

Similar effectiveness with primary HPV and cytology screening - Long-term follow-up of randomized cervical cancer screening trial

BACKGROUND

Long-term effects of primary human papillomavirus (HPV) screening on cervical cancer incidence and mortality are still missing. We conducted a long-term follow-up of the Finnish randomized HPV screening trial, the first HPV screening trial run within the routine screening program, to assess these measures.

METHODS

During 2003-2008, over 236,000 individuals were randomized (1:1) to HPV and cytology screening arms in Southern Finland. To compare the study arms, we calculated the cervical cancer incidence and mortality rate ratios using Poisson regression.

RESULTS

During a total of 3.5 million person-years of follow-up, we observed 129 cervical cancers and 32 cervical cancer deaths in the cytology arm, 139 cervical cancers and 32 cervical cancer deaths in the HPV arm. Compared to the cytology arm, in the HPV arm, the incidence rate ratio was 1.08 (95% CI 0.85-1.37), and the mortality rate ratio was 1.01 (95% CI 0.61-1.64).

CONCLUSIONS

We studied the effects of HPV screening on both cervical cancer incidence and mortality for the first time in a setting with an already well-established, high-quality cytology screening program. In this kind of setting with a low incidence of cervical cancer, HPV and cytology screening showed similar effectiveness. HPV screening provides, however, an objective, validated test system and enables self-sampling which can improve screening coverage. More attention is needed yet to ensure the balance between the harms and benefits of HPV screening.

Alternative cytology triage strategies for primary HPV screening

OBJECTIVE

Primary HPV screening programmes for cervical cancer have been implemented in many European countries using a cytology triage. Nonetheless, the optimal cytology triage strategy for minimizing the harms and maximizing the benefits is yet unclear. We identified key characteristics of different algorithms for HPV screening with cytology triage.

METHODS

Using the Finnish randomized HPV screening trial data, we formulated five post-hoc algorithms for HPV screening with a cytology triage, one for HPV screening without a triage and one for cytology screening. Sensitivity, specificity, positive predictive value, colposcopy referral rate and cumulative sensitivity for CIN II + s detected during the first and second screening rounds of the trial were calculated for all algorithms.

RESULTS

In the first screening round, direct referral of HPV positives to colposcopy led to the highest sensitivity (94%) accompanied by the lowest specificity (93%). Following HPV positives up with one repeat screen showed 86% sensitivity and 97% specificity. The corresponding figures with two repeat screens were 84% and 98%. In HPV algorithms, where cytology negative HPV positive individuals had no follow-up, the sensitivities were 65-82% and the specificities 98-99%. The Cytology algorithm had a low sensitivity (69%) with a high specificity (99%). Compared to the first round, the second-round sensitivities were lower and specificities similar or higher.

CONCLUSIONS

The best balance between sensitivity and specificity was achieved by an HPV algorithm with two repeated follow-up tests. However, all HPV algorithms with cytology triage increased colposcopy volume more than the cytology algorithm and thus provoked overdiagnosis.

Effectiveness of cervical cancer screening at age 65 - A register-based cohort study

Most cervical cancer deaths in Finland occur after the termination of the national screening program, targeted at women aged 30 to 64 years. The purpose of this study was to examine the effectiveness of screening at age 65 in reducing cervical cancer mortality. A register-based cohort study was performed with a follow-up period between 1991 and 2014. Mortality risk ratios for incident cervical cancer cases diagnosed at age 65 or older were compared between women invited and not invited for screening. The background risk difference between the studied areas was accounted for by using a reference cohort. The relative risk of death for women invited for cervical cancer screening at the age of 65 was 0.52 (95% CI: 0.29-0.94). The relative risks for women not attending and attending to screening with respect to the uninvited were 1.28 (CI: 0.65-2.50) and 0.28 (CI: 0.13-0.59), respectively. Inviting 65-year-old women for screening has been effective in reducing cervical cancer mortality.

High lifetime probability of screen-detected cervical abnormalities

Objective

Regular screening and follow-up is an important key to cervical cancer prevention; however, screening inevitably detects mild or borderline abnormalities that would never progress to a more severe stage. We analysed the cumulative probability and recurrence of cervical abnormalities in the Finnish organized screening programme during a 22-year follow-up.

Methods

Screening histories were collected for 364,487 women born between 1950 and 1965. Data consisted of 1 207,017 routine screens and 88,143 follow-up screens between 1991 and 2012. Probabilities of cervical abnormalities by age were estimated using logistic regression and generalized estimating equations methodology.

Results

The probability of experiencing any abnormality at least once at ages 30–64 was 34.0% (95% confidence interval [CI]: 33.3–34.6%). Probability was 5.4% (95% CI: 5.0–5.8%) for results warranting referral and 2.2% (95% CI: 2.0–2.4%) for results with histologically confirmed findings. Previous occurrences were associated with an increased risk of detecting new ones, specifically in older women.

Conclusion

A considerable proportion of women experience at least one abnormal screening result during their lifetime, and yet very few eventually develop an actual precancerous lesion. Re-evaluation of diagnostic criteria concerning mild abnormalities might improve the balance of harms and benefits of screening. Special monitoring of women with recurrent abnormalities especially at older ages may also be needed.

Exploiting biospectroscopy as a novel screening tool for cervical cancer: towards a framework to validate its accuracy in a routine clinical setting

Biospectroscopy is an emerging field that harnesses the platform of physical sciences with computational analysis in order to shed novel insights on biological questions. An area where this approach seems to have potential is in screening or diagnostic clinical settings, where there is an urgent need for new approaches to objectively interrogate large numbers of samples in an objective fashion with acceptable levels of sensitivity and specificity. This review outlines the benefits of biospectroscopy in screening for precancer lesions of the cervix due to its ability to separate different grades of dysplasia. It evaluates the feasibility of introducing this technique into cervical screening programs on the basis of its ability to identify biomarkers of progression within derived spectra (‘biochemical‑cell fingerprints’).

Nutritional screening for improving professional practice for patient outcomes in hospital and primary care settings

BACKGROUND

Given the prevalence of under-nutrition and reports of inadequate nutritional management of patients in hospitals and the community, nutritional screening may play a role in reducing the risks of malnutrition. Screening programmes can invoke costs to health systems and patients. It is therefore important to assess the effectiveness of nutritional screening programmes.

OBJECTIVES

To examine the effectiveness of nutritional screening in improving quality of care (professional practice) and patient outcomes compared with usual care.

SEARCH METHODS

We searched the following databases: CENTRAL (The Cochrane Library), MEDLINE, EMBASE and CINAHL up to June 2012 to find relevant studies.

SELECTION CRITERIA

Randomised controlled studies, controlled clinical trials, controlled before-after studies and interrupted time series studies assessing the effectiveness of nutritional screening were eligible for inclusion in the review. We considered process outcomes (for example patient identification, referral to dietitian) and patient outcomes (for example mortality, change in body mass index (BMI)). Participants were adult patients aged 16 years or over. We included studies conducted in different settings, including hospitals, out-patient clinics, primary care or long term care settings.

DATA COLLECTION AND ANALYSIS

We independently assessed the risk of bias and extracted data from the included studies. Meta-analysis was considered but was not conducted due to the discrepancies between the studies. The studies were heterogeneous in their design, setting, intervention and outcomes. We analysed the data using a narrative synthesis approach.

MAIN RESULTS

After conducting initial searches and screening the titles and abstracts of the identified literature, 77 full text papers were retrieved and read. Ultimately three studies were included. Two controlled before-after studies were conducted in hospital settings (one in the UK and one in the Netherlands) and one cluster randomised controlled trial was conducted in a primary care setting (in the USA).The study conducted in primary care reported that physicians were receptive to the screening intervention, but the intervention did not result in any improvements in the malnutrition detection rate or nutritional intervention rate. The two studies conducted in hospitals had important methodological limitations. One study reported that as a result of the intervention, the recording of patients' weight increased in the intervention wards. No significant changes were observed in the referral rates to dietitians or care at meal time. The third study reported weight gains and a reduction in hospital acquired infection rate in the intervention hospital. They found no significant differences in length of stay, pressure sores, malnutrition and treatment costs per patient between the two hospitals.

AUTHORS' CONCLUSIONS

Current evidence is insufficient to support the effectiveness of nutritional screening, although equally there is no evidence of no effect. Therefore, more high quality studies should be conducted to assess the effectiveness of nutritional screening in different settings.

Practice guidelines for the early detection of cervical cancer in Korea: Korean Society of Gynecologic Oncology and the Korean Society for Cytopathology 2012 edition

The consensus guideline development committee of Korean Society of Gynecologic Oncology was reconvened in March 2012. The committee consisted of 36 experts representing 12 university hospitals and professional organizations. The objective of this committee was to develop standardized guidelines for cervical cancer screening tests for Korean women and to distribute these guidelines to every clinician, eventually improving the quality of medical care. Since the establishment of the consensus guideline development committee, evidence-based guidelines have either been developed de novo considering specific Korean situations or by adaptation of preexisting consensus guidelines from other countries. Recommendations for cervical cancer screening tests, management of atypical squamous and glandular cells, and management of low-grade and high-grade squamous intraepithelial lesions were developed. Additionally, recommendations for human papillomavirus DNA testing and recommendations for adolescent and pregnant women with abnormal cervical screening test results were also included.

A framework provided an outline toward the proper evaluation of potential screening strategies

OBJECTIVES

Screening tests are often introduced into clinical practice without proper evaluation, despite the increasing awareness that screening is a double-edged sword that can lead to either net benefits or harms. Our objective was to develop a comprehensive framework for the evaluation of new screening strategies.

STUDY DESIGN AND SETTING

Elaborating on the existing concepts proposed by experts, a stepwise framework is proposed to evaluate whether a potential screening test can be introduced as a screening strategy into clinical practice. The principle of screening strategy evaluation is illustrated for cervical cancer, which is a template for screening because of the existence of an easily detectable and treatable precursor lesion.

RESULTS

The evaluation procedure consists of six consecutive steps. In steps 1-4, the technical accuracy, place of the test in the screening pathway, diagnostic accuracy, and longitudinal sensitivity and specificity of the screening test are assessed. In steps 5 and 6, the impact of the screening strategy on the patient and population levels, respectively, is evaluated. The framework incorporates a harm and benefit trade-off and cost-effectiveness analysis.

CONCLUSION

Our framework provides an outline toward the proper evaluation of potential screening strategies before considering implementation.

Detection rates of precancerous and cancerous cervical lesions within one screening round of primary human papillomavirus DNA testing: prospective randomised trial in Finland

OBJECTIVE

To compare the detection rates of precancerous and cancerous cervical lesions by human papillomavirus (HPV) DNA testing and by conventional cytology screening.

DESIGN

Prospective randomised trial. Two cohorts were followed over one screening round of five years, screened initially by primary HPV DNA testing or by primary Pap test.

SETTING

Population based programme for cervical cancer screening in Finland.

PARTICIPANTS

Women aged 25-65 years invited for screening in 2003-07 (101,678 in HPV arm; 101,747 in conventional cytology arm).

INTERVENTION

Women were randomly allocated (1:1) to primary HPV DNA screening followed by cytology triage if they had positive results, or to primary cytology screening. Screening method was disclosed at the screening visit. Trial personnel involved were aware of all test results.

MAIN OUTCOME MEASURES

Cumulative detection rates of cervical intraepithelial neoplasia (CIN), adenocarcinoma in situ (AIS), and invasive cervical cancer before the second screening (after five years) or before 31 December 2008. Lesions detected at screening and during the five year interval were included.

RESULTS

1010 and 701 precancerous or cancerous lesions were detected during an average follow-up of 3.6 years in the HPV and cytology arms, respectively. Among invited women, the hazard ratio was 1.53 (95% confidence interval l.28 to 1.84) for CIN grade 1, 1.54 (1.33 to 1.78) for CIN 2, 1.32 (1.09 to 1.59) for CIN 3 or AIS, and 0.81 (0.48 to 1.37) for cervical cancer. In 25-34 year old participants, the cumulative hazard (or cumulative detection rate) was 0.0057 (0.0045 to 0.0072) for HPV screening versus 0.0046 (0.0035 to 0.0059) for conventional screening; corresponding data for women aged 35 years and older were 0.0022 (0.0019 to 0.0026) and 0.0017 (0.0014 to 0.0021), respectively.

CONCLUSIONS

Primary HPV DNA screening detects more cervical lesions than primary cytology within one screening round of five years. Even if the detection rate of CIN 3 or AIS increased in the HPV arm in both age groups, the absolute difference in cumulative rates in women aged 35 years or older was small. By carefully selecting age groups and screening intervals, HPV screening could increase the overall detection rate of cervical precancerous lesions only slightly. However, these findings should be interpreted in the context of the high level of opportunistic screening that occurs in Finland.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial ISRCTN23885553.

Mortality audit of the Finnish cervical cancer screening program

Incidence-based evaluations of cervical cancer screening programs have suggested age-specific impacts and there is uncertainty regarding the effectiveness of screening outside the ages of 30-60 years. We audited the screening histories of cervical cancer deaths and conducted a case-control evaluation of the effectiveness of organized screening in different ages with mortality as outcome. We included all 506 cervical cancer deaths in Finland in 2000-2009 due to cancers diagnosed in 1990 or later, and 3,036 controls matched by age at diagnosis to the cases. Squamous cell carcinoma constituted 59% of the cases, adenocarcinomas 29%, and the remaining 12% were other specified and unspecified cervical malignancies. Most deaths (54%) were due to cancers diagnosed more than 5 years after last screening invitation, 24% were diagnosed among nonattenders and only 14% of deaths occurred among women who had attended invitational screening. The risk reduction associated with attending a single program screen at an age below 40 was nonsignificant (OR 0.70; 95% CI 0.33-1.48), while clear risk reductions were observed after screening at the age of 40-54 (OR 0.33; CI 0.20-0.56) and 55-69 (OR 0.29; CI 0.16-0.54). This study also provides some indication of a long-lasting additional effect of screening at the age of 65. Possible avenues for improving the effectiveness of the Finnish screening program include efforts to increase attendance and an extension of the target ages to include 65-to 69-year-old women. The potential benefit of increasing the sensitivity of the screening test or shortening the screening interval is smaller.

Validation of histological diagnoses in a national cervical screening register

BACKGROUND

Monitoring and evaluation of cancer screening programmes require accurate data on invitations, visits, test results, diagnoses and management. The purpose of this study was to evaluate the completeness and accuracy of histological diagnoses (cervical precancerous lesions and cancer) in the Finnish cervical cancer screening register by comparing data with the cancer register and the administrative hospital discharge register.

MATERIAL AND METHODS

Screening data covering all 16 353 screening episodes that resulted in a referral for colposcopy over the period of 1998-2007 were individually linked with hospital discharge and cancer register data using the unique personal identifier. Agreement between registers, as well as sensitivity, coverage and positive predictive values (PPV) for the screening register and the hospital discharge register diagnosis, were estimated. Invasive cases in the cancer register and pooled cases of precancerous lesions were used as reference case populations.

RESULTS

The sensitivity of the screening register for cervical cancer was 69%, the coverage 100% and the PPV 77%. Corresponding values for the hospital discharge register were 81%, 100% and 83%, respectively. Sensitivity of the screening register for cervical intraepithelial neoplasia grade 2 or worse (CIN2+) against the pooled case population was 89% and coverage 99%. Corresponding values for the hospital discharge register were 78% and 93%. Kappa-values for pair-wise agreement between the three registers ranged between 0.73 and 0.79, often the lesion grade was lower in the screening register than in the other two registers.

CONCLUSIONS

The data in the screening register has high coverage and is thus useful for statistical and evaluation purposes. However, in order to improve the accuracy of diagnostic information, there are grounds to consider data retrieval through systematic linkage to other health care registers.

Self-sampling versus reminder letter: effects on cervical cancer screening attendance and coverage in Finland

Optimizing attendance and coverage of organized screening is needed to reduce cervical cancer incidence to previous lower levels. In our study, all nonparticipants in organized cervical cancer screening in 2008 in Espoo, Finland were randomized to receive a self-sampling kit (1,130 women) or a reminder letter (3,030 women). Effects on screening coverage were assessed according to the self-reported previous Pap smear history of the participants. Participation rate in the self-sampling arm, 29.8%, was significantly higher than in the reminder letter arm, 26.2% (adjusted relative risk for participation 1.13). Total participation in Espoo in 2008 rose significantly after the two interventions from 64.0 to 75.4%. In both arms, ∼ 20% of the participants after second intervention could be considered under screened (previous Pap smear ≥ 5 years ago) and thus increased screening coverage. Respectively, for 70-75%, the second intervention only provided overscreening. Participation was lowest among young age groups and immigrants, after primary invitation and after interventions. Our study shows that a second intervention for nonattendees after the first invitation is needed to optimize the attendance rates. Self-sampling might be slightly more successful in this, but the effects on screening coverage were similar in both groups.

Rate of cervical cancer, severe intraepithelial neoplasia, and adenocarcinoma in situ in primary HPV DNA screening with cytology triage: randomised study within organised screening programme

OBJECTIVE

To assess the performance and impact of primary human papillomavirus (HPV) DNA screening with cytology triage compared with conventional cytology on cervical cancer and severe pre-cancerous lesions.

DESIGN

Randomised trial.

SETTING

Population based screening programme for cervical cancer in southern Finland in 2003-5.

PARTICIPANTS

58 076 women, aged 30-60, invited to the routine population based screening programme for cervical cancer.

INTERVENTIONS

Primary HPV DNA test (hybrid capture II) with cytology triage if the result was positive or conventional cytological screening (reference).

MAIN OUTCOME MEASURES

Rate of cervical cancer, cervical intraepithelial neoplasia (CIN) grade III, and adenocarcinoma in situ (as a composite outcome referred to as CIN III+) during 2003-7 through record linkage between files from the screening registry and the national cancer registry.

RESULTS

In the HPV and conventional arms there were 95 600 and 95 700 woman years of follow-up and 76 and 53 cases of CIN III+, respectively (of which six and eight were cervical cancers). The relative rate of CIN III+ in the HPV arm versus the conventional arm was 1.44 (95% confidence interval 1.01 to 2.05) among all women invited for screening and 1.77 (1.16 to 2.74) among those who attended. Among women with a normal or negative test result, the relative rate of subsequent CIN III+ was 0.28 (0.04 to 1.17). The rate of cervical cancer between arms was 0.75 (0.25 to 2.16) among women invited for screening and 1.98 (0.52 to 9.38) among those who attended.

CONCLUSIONS

When incorporated into a well established organised screening programme, primary HPV screening with cytology triage was more sensitive than conventional cytology in detecting CIN III+ lesions. The number of cases of cervical cancer was small, but considering the high probability of progression of CIN III the findings are of importance regarding cancer prevention.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN23885553.

Age-specific evaluation of primary human papillomavirus screening vs conventional cytology in a randomized setting

BACKGROUND

Human papillomavirus (HPV) DNA testing has shown higher sensitivity than cytology for detecting cervical lesions, but it is uncertain whether the higher sensitivity is dependent on the age of the woman being screened. We compared the age-specific performance of primary HPV DNA screening with that of conventional cytology screening in the setting of an organized population-based cervical cancer screening program in Finland.

METHODS

From January 1, 2003, to December 31, 2005, randomized invitations were sent to women aged 25-65 years for routine cervical cancer screening by primary high-risk HPV DNA testing (n = 54 207) with a Hybrid Capture 2 assay followed by cytology triage for women who were HPV DNA positive or by conventional cytology screening (n = 54 218). In both screening arms, cytology results of low-grade squamous intraepithelial lesion or worse triggered a referral for colposcopy. Relative rates (RRs) of detection to assess test sensitivity, specificity, and positive predictive values (PPVs) with 95% confidence intervals (CIs) were calculated for the histological endpoints of cervical intraepithelial neoplasia (CIN) grade 1 or higher (CIN 1+), CIN grade 2 or higher (CIN 2+), and CIN grade 3 or higher (CIN 3+). All statistical tests were two-sided.

RESULTS

The overall frequency of colposcopy referrals was 1.2% in both screening arms. Women younger than 35 years were referred more often in the HPV DNA screening vs the conventional screening arm (RR = 1.27, 95% CI = 1.01 to 1.60). The prevalence of histologically confirmed CIN or cancer was 0.59% in the HPV DNA screening arm vs 0.43% in the conventional screening arm. The relative rates of detection for CIN 1, CIN 2, and CIN 3+ for HPV DNA screening with cytology triage vs conventional screening were 1.44 (95% CI = 0.99 to 2.10), 1.39 (95% CI = 1.03 to 1.88), and 1.22 (95% CI = 0.78 to 1.92), respectively. The specificity of the HPV DNA test with cytology triage was equal to that of conventional screening for all age groups (99.2% vs 99.1% for CIN 2+, P = .13). Among women aged 35 years or older, the HPV DNA test with cytology triage tended to have higher specificity than conventional screening. The PPVs for HPV DNA screening with cytology triage were consistently higher than those for conventional screening. In both screening arms, the test specificities increased with increasing age of the women being screening, whereas the highest PPVs were observed among the youngest women being screened. Overall, 7.2% of women in the HPV DNA screening arm vs 6.6% of women in the conventional screening arm were recommended for intensified follow-up, and the percentages were highest among 25- to 29-year-olds (21.9% vs 10.0%, respectively).

CONCLUSIONS

Primary HPV DNA screening with cytology triage is more sensitive than conventional screening. Among women aged 35 years or older, primary HPV DNA screening with cytology triage is also more specific than conventional screening and decreases colposcopy referrals and follow-up tests.

Prevalence of oncogenic human papillomavirus infection in an organised screening population in Finland

A persistent high-risk human papillomavirus (hrHPV) infection is a necessary condition for developing a cervical intraepithelial neoplasia and cervical cancer. The viral aetiology in cervical carcinogenesis has stimulated attempts to use HPV DNA detection in cervical cancer screening. In Finland there is an ongoing study assessing the benefits of primary HPV DNA testing in the setting of centrally organised mass screening for cervical cancer. Here we present the age-specific prevalence of hrHPV infection and associated sociodemographic factors of 16,895 women aged 25-65 years attending the 5-yearly cervical cancer screening between years 2003 and 2004. The overall hrHPV prevalence rate was 7.5%. The peak prevalence at the age group of 25-29 was 24.1% decreasing steadily thereafter to approximately 2.9% in women aged 65 years. Young age and marital status were the main determinants for oncogenic HPV types. Our study confirms the inverse relationship between age and hrHPV prevalence reported in many developed countries. As our prevalence rates and hence background risk for cervical cancer are not lower than in other European countries, it is likely that our lowest cervical cancer burden in Europe is due to health care actions justifying the organised cervical cancer screening.