Breast Cancer, Ductal Carcinoma in Situ
Conditions
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.
Interventions
DIAGNOSTIC_TESTBreast Screening Mammography with single reader
One clinician examined each woman's mammograms for signs of cancer
DIAGNOSTIC_TESTBreast screening mammography with two readers
Two clinicians seperately examined each woman's mammograms for signs of cancer
DIAGNOSTIC_TESTTest threshold
Threshold used by readers examining the breast screening mammograms, defined using their previous proportion of cases recalled
Sponsors
Public Health England
University of Warwick
Study design
Observational model
COHORT
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
FEMALE
Age
47 Years to 73 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| All cause mortality | 13 years, and up to 30 years | Mortality due to any cause (dependent on securing follow on funding) |
| False positive recalls | 1 day screening episode | Recall of women for further tests after screening which did not result in detection of cancer |
| Breast cancer mortality | 13 years, and up to 30 years | Mortality due to breast cancer (dependent on securing follow-on funding) |
| 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). |
| 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) |
| Cancers detected at screening | 1 day screening episode | Biopsy proven cancers detected at screening |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Breast cancer free survival | Up to 30 years follow-up | Survival without a diagnosis of breast cancer |
| 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) |
Countries
United Kingdom
Outcome results
None listed