British society of breast radiology annual scientific meeting abstracts

Breast Cancer Research 2026 28(1):O2 Introduction: Before NICE guideline NG101 was updated in 2023, mammographically occult breast cancer posed a post-treatment surveillance challenge, as mammography alone was often deemed insufficient and national guidance was unclear.Consequently, two breast centres, at The Princess Alexandra Hospital NHS Trust (PAH) and East & North Hertfordshire Teaching NHS Trust (ENHT), implemented annual MRI surveillance.To assess alignment with NG101, which now advises against routine MRI in these patients, we evaluated 18 years of surveillance data for diagnostic value.Methods: We retrospectively reviewed post-treatment MRI and digital mammography surveillance scans at PAH (2006-2024) and ENHT (2010-2023).Only routine surveillance scans were included; neoadjuvant cases, high-risk family histories, and short-term follow-ups were excluded.Outcomes included recall rates, biopsy results, and cancer detection.Results: Across both centres, 739 MRI scans in 169 women generated 31 recalls (4.2%), of which 22 were benign and 9 malignant (1.2%).Only 3 cancers (0.4%) were visible on MRI alone, equating to 1 additional cancer for approximately every 246 scans performed.At PAH (225 scans, 69 women), 7 recalls produced 4 benign and 3 malignant biopsies; just 1 cancer (0.4%) was MRI-only (N.B. this pre-dated digital mammography).At ENHT (514 scans, 100 women), 24 recalls yielded 18 benign and 6 malignant biopsies; only 2 cancers (0.4%) were MRI-only.Conclusions: Real-world evidence supports national guidance: routine MRI surveillance after treatment for mammographically occult breast cancer incurs substantial resource use and patient anxiety for minimal diagnostic benefit.MRI should therefore be reserved for defined high-risk subgroups following multidisciplinary discussion.