Does a booklet on breast self-examination improve subsequent detection rates?

Of 28 788 women aged 40 to 74 registered at 28 university teaching practices in greater Belfast, half were randomly selected to receive a booklet on breast self-examination from their general practitioner at the start of the study and 1 year later. The frequency of breast abnormalities was identical in both groups (0.83%) during the 2-year follow-up. Early malignant breast cancers (stages TX, TO, Tla) were significantly more frequent in the intervention group (53.6%) than in the control group (24.3%). Among women in the intervention group with malignant lesions, 2 sites, left nipple and left inner/upper quadrant, were significantly less frequently involved. These findings in relation to staging and site were confirmed by multivariate comparisons. The intervention group also had a smaller average tumour size (24.0 mm compared with 32.6 mm) due to significantly smaller benign tumours and the absence of the relationship between delay and tumour size evident in the control group.