Meeting Abstracts from the British Society of Breast Radiology Annual Scientific Meeting 2024

BackgroundMammographic density (MD) is a well-established breast cancer risk factor.Decreasing MD has been demonstrated to be a risk-reduction biomarker in a landmark chemoprevention study in high-risk women.A few small studies suggest that a decreasing MD in women taking adjuvant endocrine therapy (AET) may be associated with a lower risk of recurrence and breast cancer specific death.Aim This interim analysis aims to measure inter and intra-reader variability of MD classification within a current study (MEDICI) investigating whether a reduction in MD after one and/or three years in women taking AET is associated with a lower risk of breast cancer recurrence and death compared to no reduction.Methods Retrospective cohort study, generated from a subset of participants from the Mammo-50 trial.Eleven readers assessed MD using a 0 to 100% visual analogue scale (VAS), scoring mammograms from time of diagnosis and at one and three years after diagnosis.A subset of four readers re-analysed the mammograms.Inter and intra-reader agreement were estimated using intra-class correlation coefficients (ICC). ResultsEleven readers classified MD in 50 patients at three timepoints (150 mammograms), using the VAS.Four readers re-interpreted all 150 mammograms.The ICC between all 11 readers (inter-reader agreement) was 0.80 (95% confidence interval (CI): 0.77-0.84).The ICC within readers (intra-reader agreement) was 0.86 (95% CI 0.77-0.91). ConclusionInterim analysis demonstrates good inter-and intra-reader agreement for assessment of MD on VAS, suggesting validity of the human MD assessment to be performed within the MEDICI study O4.