Patient Outcomes from Second Film-readers and Test Threshold Relaxation in Breast Screening

Completed

• Conditions: Breast Cancer; Ductal Carcinoma in Situ
• Interventions: Diagnostic Test: Breast screening mammography with two readers; Diagnostic Test: Breast Screening Mammography with single reader; Diagnostic Test: Test threshold

• Registration Number: NCT04365114
• Lead Sponsor: University of Warwick

Brief Summary

Analysis of women's medical records to understand the impact of previous changes to breast cancer screening (increase from one to two clinicians examining each woman's mammograms, and what proportion of women they recall for further tests)

Detailed Description

Retrospective observational study examining the records and outcomes of women who attended breast cancer screening between 1988 and 2016. Linkage of records from the breast screening service, the cancer registry, and mortality. Analysis of whether changing the threshold for whether to recall women for further tests or the number of clinicians examining the mammograms for signs of cancer affects outcomes.

Study Timeline

• Study Start: 2018-10-01
• Study First Submitted: 2020-04-24
• Study First Submitted QC: 2020-04-27
• Study First Posted: 2020-04-28
• Primary Completion: 2024-12-30
• Study Completion: 2024-12-30
• Status Verified: 2025-01
• Last Update Submitted: 2025-01-21
• Last Update Posted: 2025-01-24

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 13094122

Inclusion Criteria

• Women who attended the English National Health Service (NHS) breast cancer screening service at least once between 1988 and 2016, aged between 47 and 73
• All eligible episodes of screening for each woman (we expect women to be screened around 7 times each)

Exclusion Criteria

• Women who did not attend routine English NHS Breast screening service within the specified date and age range, even if they attended symptomatic breast cancer services, high risk (family history) breast screening services, or if they were referred for mammograms by their general practitioner

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Double reading	Breast screening mammography with two readers	Two clinicians examined the woman's mammograms for signs of cancer and recommended whether to recall her for further tests or not.
Single reading	Test threshold	Only one clinician examined the woman's mammograms for signs of cancer and recommended whether to recall her for further tests or not.
Single reading	Breast Screening Mammography with single reader	Only one clinician examined the woman's mammograms for signs of cancer and recommended whether to recall her for further tests or not.
Double reading	Test threshold	Two clinicians examined the woman's mammograms for signs of cancer and recommended whether to recall her for further tests or not.

Primary Outcome Measures

Name	Time	Method
All cause mortality	13 years, and up to 30 years	Mortality due to any cause (dependent on securing follow on funding)
Number of women overdiagnosed (the cancer would not have become symptomatic within the woman's lifetime) using compensatory drop method	13 years, and up to 30 years	Overdiagnosis of breast cancer (measured as difference in total cancer incidence, screen and symptomatic). Will also report mechanism of action (number of screen detected cancers, number of symptomatically detected cancers at 3,13, and 30 years follow-up)
False positive recalls	1 day screening episode	Recall of women for further tests after screening which did not result in detection of cancer
Characteristics of cancer detected	1 day screening episode, 3year, 13 year and up to 30 year follow up	Size, grade and stage (reported overall, screen detected, and symptomatic detected).
Cancers detected at screening	1 day screening episode	Biopsy proven cancers detected at screening
Breast cancer mortality	13 years, and up to 30 years	Mortality due to breast cancer (dependent on securing follow-on funding)

Secondary Outcome Measures

Name	Time	Method
Breast cancer morbidity	Up to 30 years	Treatment received as a proxy for treatment associated morbidity (reported overall, screen detected and symptomatically detected, if follow on funding obtained)
Breast cancer free survival	Up to 30 years follow-up	Survival without a diagnosis of breast cancer

Trial Locations

Locations (1)

Univesity of Warwick; 🇬🇧 Coventry, Warwickshire, United Kingdom