['To determine the efficacy of screening women under age 50 with a significant family history of breast cancer.', 'Results from 22 Breast Units in the UK identified as being able to provide data were surveyed and pooled through regional data managers or consultant breast specialists.', 'Data relating to 8783 women screened and 9075 woman years of follow-up was analysed. Cancer incidence was 11.3/1000/year. The rate of cancer detection was 4. 78/1000 at prevalent screening and 4.52/1000 at incident screening. Median age at diagnosis was 43 years. Interval cancers presented at a rate of 2.45/1000. Comparison with the National Health Service Breast Screening Programme for women aged 50-64 revealed a similar rate of cancer detection and a similar incidence of ductal carcinoma in situ. The pathological features of screen-detected cancers in this study strongly suggest that prognosis for these women is more favourable than if they had presented symptomatically.'] Does screening women with a family history of breast cancer -- result from the British Familial Breast Cancer Group?