Interval cancers are cancers diagnosed after a normal screening mammogram and before the next scheduled screening. Interval cancers are inherent to every screening programme. A regular review of interval cancers is important for the following reasons:
The rate of interval breast cancers in every screening unit is a key performance indicator for a breast screening programme’s effectiveness.
For education and learning purposes and continuous professional development of the screening readers, to improve the quality of the programme.
To help women diagnosed with interval breast cancer...
Methods and materials
This was a retrospective analysis of the G3 interval cancers diagnosed in our breast screening unit from April 2016 to April 2019. The screening population of the Unit is seventy eight thousand.
The breast screening programme in the UK offers screening once every three years to woman between 50 to 70 years old, with some extensions in certain trials to women aged 47 to 73 years old.
All the G3 interval cancers were anonymised and analysed by a group of six breast...
Interval cancers(Fig. 5)
One hundred and sixteenwomen were diagnosed with aninterval breast cancer, which represents an average of 2.1 women per 1000 women screened in our unit, which is in line withtheNHS Breast Screening Programme (2.2-3.7/1000 women screened) and European rates (0.8-2.1/1000 women screened) (3).
Mostof the interval cancers were diagnosed in the first two years after the screening mammogram.Forty-sixof the interval cancers were grade 3 IDC or ILC, which represents 40% of all the intervalcancers.
Type of interval
Ofthe46 G3 interval cancers,36 were category...
Our studyhasshownthat G3 invasive interval cancers are usually occult or not present in thescreeningmammogram (90%) and presentsoonafter thescreening mammogram. Although theyarelarger by the time of diagnosis, the majority are stage I, with no axillary involvement (76%).
The rate of interval cancers can be used asaperformance indicatorfora screening unit. Asystematic and continued review of the interval cancers would allow the screen readers to get familiar with early radiological findings of G3 breast cancer (usually small asymmetric densities) andimprove the quality of the service.
Personal information and conflict of interest
T. Presa; London/UK - nothing to disclose M. Moreland; Maidenhead/UK - nothing to disclose A. Kumar; Slough/UK - nothing to disclose J. K. Juttla; Harrow/UK - nothing to disclose
Guidance on applyingDuty ofCandour and disclosing audit results. NHS Screening Programmes. NHS England. September2016.
NHS England. NHS Breast ScreeningProgramme: reporting, classification and monitoring of interval cancers following previous assessment. August 2017.
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