The UK very high-risk (VHR) National Breast Screening Programme (NHSBSP): screen detected cancers from a 3-year screening round (2021-2024): a multi-institutional review

Abstract

The VHR NHSBSP screens women with VHR genes and supradiaphragmatic radiotherapy aged 10-35 (XRTC). The VHR programme aims to optimise screening modalities to detect malignancy at the earliest possible stage in these populations to improve outcomes. This multi-institutional study reviews screening modality, mode of detection, demographics and characteristics of VHR screen detected cancers. Screening and clinical data for all VHR screen detected cancers from 5 screening services from 2021-2024 were reviewed. There were 87 VHR cancers. The age range at acceptance was 29-77 years and the age range at diagnosis was 29-79. 21.8% had mammograms, 29.9% had MRI alone and 48.3% combined. BRCA1/2 carriers were the majority of the cancers (77.0%), 5.7% had other variants and 17.2% had XRTC. 58.6% of cancers were diagnosed on MRI alone with 16.1% diagnosed on both MRI and mammography but only 25.2% diagnosed on mammography alone. The mammographic density were dense (c and d 52/76 = 88.4%) with only 5.3% (4/76) completely adipose. There were 21 DCIS-all were high (HG) (66.7%) or intermediate grade (IG). Of the 87 cancers, 49 underwent bilateral mastectomies. There were 3 upgrades on imaging size, and 3 pathological upgrades (2 were upgraded from grade 2 to 3 and 1 from IG to HG DCIS). There were 4 unsuspected contralateral malignancies (4 DCIS and a 2.2 mm IDC and DCIS). The findings show effectiveness of mammography and MRI with the majority of cancers in dense breasts. Mastectomy data shows no significant undiagnosed disease in the contralateral breast.