Assessment of changes to screening programmes: why randomisation is important

Systematic review and meta-analysis of prognostic characteristics for breast cancers in populations with digital vs film mammography indicate the transition may have increased both early detection and overdiagnosis

OBJECTIVES

Film mammography has been replaced by digital mammography in breast screening programs globally. This led to a small increase in the rate of detection, but whether the detection of clinically important cancers increased is uncertain. We aimed to assess the impact on tumor characteristics of screen-detected and interval breast cancers.

STUDY DESIGN AND SETTING

We searched seven databases from inception to October 08, 2023, for publications comparing film and digital mammography within the same population of asymptomatic women at population (average) risk of breast cancer. We recorded reported tumor characteristics and assessed risk of bias using the Risk Of Bias In Non-randomised Studies - of Interventions tool. We synthesized results using meta-analyses of random effects.

RESULTS

Eighteen studies were included in the analysis from 8 countries, including 11,592,225 screening examinations (8,117,781 film; 3,474,444 digital). There were no differences in tumor size, morphology, grade, node status, receptor status, or stage in the pooled differences for screen-detected and interval invasive cancer tumor characteristics. There were statistically significant increases in screen-detected ductal carcinoma in situ (DCIS) across all grades: 0.05 (0.00-0.11), 0.14 (0.05-0.22), and 0.19 (0.05-0.33) per 1000 screens for low, intermediate, and high-grade DCIS, respectively. There were similar (non-statistically significant) increases in screen-detected invasive cancer across all grades.

CONCLUSION

The increased detection of all grades of DCIS and invasive cancer may indicate both increased early detection of more aggressive disease and increased overdiagnosis.

Impact of Full-Field Digital Mammography Versus Film-Screen Mammography in Population Screening: A Meta-Analysis

BACKGROUND

Breast screening programs replaced film mammography with digital mammography, and the effects of this practice shift in population screening on health outcomes can be measured through examination of cancer detection and interval cancer rates.

METHODS

A systematic review and random effects meta-analysis were undertaken. Seven databases were searched for publications that compared film with digital mammography within the same population of asymptomatic women and reported cancer detection and/or interval cancer rates.

RESULTS

The analysis included 24 studies with 16 583 743 screening examinations (10 968 843 film and 5 614 900 digital). The pooled difference in the cancer detection rate showed an increase of 0.51 per 1000 screens (95% confidence interval [CI] = 0.19 to 0.83), greater relative increase for ductal carcinoma in situ (25.2%, 95% CI = 17.4% to 33.5%) than invasive (4%, 95% CI = -3% to 13%), and a recall rate increase of 6.95 (95% CI = 3.47 to 10.42) per 1000 screens after the transition from film to digital mammography. Seven studies (80.8% of screens) reported interval cancers: the pooled difference showed no change in the interval cancer rate with -0.02 per 1000 screens (95% CI = -0.06 to 0.03). Restricting analysis to studies at low risk of bias resulted in findings consistent with the overall pooled results for all outcomes.

CONCLUSIONS

The increase in cancer detection following the practice shift to digital mammography did not translate into a reduction in the interval cancer rate. Recall rates were increased. These results suggest the transition from film to digital mammography did not result in health benefits for screened women. This analysis reinforces the need to carefully evaluate effects of future changes in technology, such as tomosynthesis, to ensure new technology leads to improved health outcomes and beyond technical gains.

Long-term cardiometabolic disease risk in women with PCOS: a systematic review and meta-analysis

BACKGROUND

Polycystic ovary syndrome (PCOS) is associated with cardiometabolic disease, but recent systematic reviews and meta-analyses of longitudinal studies that quantify these associations are lacking.

OBJECTIVE AND RATIONALE

Is PCOS a risk factor for cardiometabolic disease?

SEARCH METHODS

We searched from inception to September 2019 in MEDLINE and EMBASE using controlled terms (e.g. MESH) and text words for PCOS and cardiometabolic outcomes, including cardiovascular disease (CVD), stroke, myocardial infarction, hypertension (HT), type 2 diabetes (T2D), metabolic syndrome and dyslipidaemia. Cohort studies and case–control studies comparing the prevalence of T2D, HT, fatal or non-fatal CVD and/or lipid concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TGs) between women with and without PCOS of ≥18 years of age were eligible for this systematic review and meta-analysis. Studies were eligible regardless of the degree to which they adjusted for confounders including obesity. Articles had to be written in English, German or Dutch. Intervention studies, animal studies, conference abstracts, studies with a follow-up duration less than 3 years and studies with less than 10 PCOS cases were excluded. Study selection, quality assessment (Newcastle–Ottawa Scale) and data extraction were performed by two independent researchers.

OUTCOMES

Of the 5971 identified records, 23 cohort studies were included in the current systematic review. Women with PCOS had increased risks of HT (risk ratio (RR): 1.75, 95% CI 1.42 to 2.15), T2D (RR: 3.00, 95% CI 2.56 to 3.51), a higher serum concentration of TC (mean difference (MD): 7.14 95% CI 1.58 to 12.70 mg/dl), a lower serum concentration of HDL-C (MD: −2.45 95% CI −4.51 to −0.38 mg/dl) and increased risks of non-fatal cerebrovascular disease events (RR: 1.41, 95% CI 1.02 to 1.94) compared to women without PCOS. No differences were found for LDL-C (MD: 3.32 95% CI −4.11 to 10.75 mg/dl), TG (MD 18.53 95% CI −0.58 to 37.64 mg/dl) or coronary disease events (RR: 1.78, 95% CI 0.99 to 3.23). No meta-analyses could be performed for fatal CVD events due to the paucity of mortality data.

WIDER IMPLICATIONS

Women with PCOS are at increased risk of cardiometabolic disease. This review quantifies this risk, which is important for clinicians to inform patients and to take into account in the cardiovascular risk assessment of women with PCOS. Future clinical trials are needed to assess the ability of cardiometabolic screening and management in women with PCOS to reduce future CVD morbidity.

Can patient-led surveillance detect subsequent new primary or recurrent melanomas and reduce the need for routinely scheduled follow-up? A protocol for the MEL-SELF randomised controlled trial

BACKGROUND

Most subsequent new primary or recurrent melanomas might be self-detected if patients are trained to systematically self-examine their skin and have access to timely medical review (patient-led surveillance). Routinely scheduled clinic visits (clinician-led surveillance) is resource-intensive and has not been shown to improve health outcomes; fewer visits may be possible if patient-led surveillance is shown to be safe and effective. The MEL-SELF trial is a randomised controlled trial comparing patient-led surveillance with clinician-led surveillance in people who have been previously treated for localised melanoma.

METHODS

Stage 0/I/II melanoma patients (n = 600) from dermatology, surgical, or general practice clinics in NSW Australia, will be randomised (1:1) to the intervention (patient-led surveillance, n = 300) or control (usual care, n = 300). Patients in the intervention will undergo a second randomisation 1:1 to polarised (n = 150) or non-polarised (n = 150) dermatoscope. Patient-led surveillance comprises an educational booklet, skin self-examination (SSE) instructional videos; 3-monthly email/SMS reminders to perform SSE; patient-performed dermoscopy with teledermatologist feedback; clinical review of positive teledermoscopy through fast-tracked unscheduled clinic visits; and routinely scheduled clinic visits following each clinician's usual practice. Clinician-led surveillance comprises an educational booklet and routinely scheduled clinic visits following each clinician's usual practice. The primary outcome, measured at 12 months, is the proportion of participants diagnosed with a subsequent new primary or recurrent melanoma at an unscheduled clinic visit. Secondary outcomes include time from randomisation to diagnosis (of a subsequent new primary or recurrent melanoma and of a new keratinocyte cancer), clinicopathological characteristics of subsequent new primary or recurrent melanomas (including AJCC stage), psychological outcomes, and healthcare use. A nested qualitative study will include interviews with patients and clinicians, and a costing study we will compare costs from a societal perspective. We will compare the technical performance of two different models of dermatoscope (polarised vs non-polarised).

DISCUSSION

The findings from this study may inform guidance on evidence-based follow-up care, that maximises early detection of subsequent new primary or recurrent melanoma and patient wellbeing, while minimising costs to patients, health systems, and society.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12621000176864 . Registered on 18 February 2021.

Participation and Ease of Use in Colorectal Cancer Screening: A Comparison of 2 Fecal Immunochemical Tests

INTRODUCTION

The impact of fecal immunochemical test (FIT)-based colorectal cancer (CRC) screening on disease incidence and mortality is affected by participation, which might be influenced by ease of use of the FIT. We compared the participation rates and ease of use of 2 different FITs in a CRC screening program.

METHODS

There were two study designs within the Dutch CRC screening program. In a paired cohort study, all invitees received 2 FITs (OC-Sensor, Eiken, Japan, and FOB-Gold, Sentinel, Italy) and were asked to sample both from the same stool. Ease of use of both FITs was evaluated by a questionnaire. In a randomized controlled trial, invitees were randomly allocated to receive one of the 2 FITs to compare participation and analyzability.

RESULTS

Of 42,179 invitees in the paired cohort study, 21,078 (50%) completed 2 tests and 20,727 (98%) returned the questionnaire. FOB-Gold was reported significantly easier to use. More participants preferred FOB-Gold (36%) than OC-Sensor (5%), yet most had no preference (59%; P < 0.001). In the randomized trial, 936 of 1,923 invitees (48.7%) returned the FOB-Gold and 940 of 1,923 invitees (48.9%) returned the OC-Sensor, a difference of -0.2% (confidence interval, -3.4% to 3.0%), well within the pre-specified 5% noninferiority margin (P = 0.001). Only one FOB-Gold (0.1%) and 4 OC-Sensors (0.4%) were not analyzable (P = 0.18).

CONCLUSIONS

Although FOB-Gold was significantly but marginally considered easier to use than OC-Sensor, the number of analyzable tests and the participation rates in organized CRC screening are not affected when either of the FITs is implemented as a primary screening test.

Equivalent Accuracy of 2 Quantitative Fecal Immunochemical Tests in Detecting Advanced Neoplasia in an Organized Colorectal Cancer Screening Program

BACKGROUND & AIMS

Although different brands of fecal immunochemical tests (FITs) are used for colorectal cancer (CRC) screening, few studies have compared their accuracy in detecting advanced neoplasia.

METHODS

We performed a large prospective cohort study within the Dutch national CRC screening program to evaluate 2 quantitative FITs: FOB-Gold (Sentinel, Milan, Italy) and OC-Sensor (Eiken Chemical, Tokyo Japan), from May 2016 through March 2017. We randomly selected 42,179 screening-naïve individuals (55-75 years old), who were asked to perform both FITs themselves using the same bowel movement. Participants with positive results from 1 or both FITs (≥15 μg hemoglobin/gram feces) were invited for colonoscopy examination (reference standard). Equivalence in detection of advanced neoplasia was evaluated with a predefined margin of 0.15%.

RESULTS

Of 42,179 invitees, 22,064 (52%) participated and FITs were completed for 21,078 participants. Of 2112 participants (9.6%) with 1 or 2 positive results from FITs, 1778 (84%) underwent a colonoscopy. Of all invitees, the FOB-Gold test detected advanced neoplasia (confirmed by colonoscopy) in 610 participants (1.45%) and the OC-Sensor detected advanced neoplasia (confirmed by colonoscopy) in 606 participants (1.44%)-an absolute difference of 0.01% (95% confidence interval [CI], -0.06% to 0.08%). Of the 21,078 participants who completed both FITs, 1582 (7.5%) had a positive result from the FOB-Gold test and 1627 (7.7%) a positive result from the OC-Sensor test (P = .140). The relative true-positive rate of FOB-Gold vs OC-Sensor in detecting advanced neoplasia was 0.97 (95% CI, 0.92-1.01) and 0.95 (95% CI, 0.87-1.03) for CRC. The relative false-positive rate of the FOB-Gold test vs the OC-Sensor test in detecting advanced neoplasia was 0.99 (95% CI, 0.93-1.05).

CONCLUSIONS

In a large prospective study of individuals invited for CRC screening in The Netherlands, we found equivalent accuracy of the FOB-Gold FIT vs the OC-Sensor FIT in detecting advanced neoplasia. These results are relevant for selecting FITs for CRC screening programs worldwide. Dutch National Trial Registry: NTR5874.

Prevalence of incidental breast cancer and precursor lesions in autopsy studies: a systematic review and meta-analysis

Background

Autopsy studies demonstrate the prevalence pool of incidental breast cancer in the population, but estimates are uncertain due to small numbers in any primary study. We aimed to conduct a systematic review of autopsy studies to estimate the prevalence of incidental breast cancer and precursors.

Methods

Relevant articles were identified through searching PubMed and Embase from inception up to April 2016, and backward and forward citations. We included autopsy studies of women with no history of breast pathology, which included systematic histological examination of at least one breast, and which allowed calculation of the prevalence of incidental breast cancer or precursor lesions. Data were pooled using logistic regression models with random intercepts (non-linear mixed models).

Results

We included 13 studies from 1948 to 2010, contributing 2363 autopsies with 99 cases of incidental cancer or precursor lesions. More thorough histological examination (≥20 histological sections) was a strong predictor of incidental in-situ cancer and atypical hyperplasia (OR = 126·8 and 21·3 respectively, p < 0·001), but not invasive cancer (OR = 1·1, p = 0·75). The estimated mean prevalence of incidental cancer or precursor lesion was 19·5% (0·85% invasive cancer + 8·9% in-situ cancer + 9·8% atypical hyperplasia).

Conclusion

Our systematic review in ten countries over six decades found that incidental detection of cancer in situ and breast cancer precursors is common in women not known to have breast disease during life. The large prevalence pool of undetected cancer in-situ and atypical hyperplasia in these autopsy studies suggests screening programs should be cautious about introducing more sensitive tests that may increase detection of these lesions.

To Screen or Not to Screen: Reconciling Individual and Population Perspectives on Screening

Screening is the early detection of a latent disorder by a test to allow early intervention with the aim of improving prognosis. Individual and population perspectives on screening are perceived as opposing interests of patients and the population. In this article, we try to reconcile these perspectives. The individual perspective is based on the clinical experience of a better prognosis at early stages and patients with missed opportunities. In the population perspective, screening is based on a population-oriented, evidence-based model and addresses the acceptability and possible negative effects, including for people without the disorder. Known possible obstacles to a positive effect of screening include a short latent stage, lead time, overdiagnosis, lack of acceptability, poor performance of tests, and misclassification of outcome. Randomized trials of screening are challenging and need an adaptation of standards such as the Consolidated Standards of Reporting Trials (CONSORT). Simulating the effects of screening can allow the consideration of complex screening strategies and other options to help avoid biases related to treatment improvement and prevention success. Reconciling both perspectives is possible by considering that hypotheses underlying the former are prerequisites for the latter. From an evidence-based medicine and policy perspective, we suggest that recommending screening or prescribing a test is unethical if all possible obstacles are not documented by providing the best available evidence.