Self examination of the breast: is it beneficial? Meta-analysis of studies investigating breast self examination and extent of disease in patients with breast cancer.

The question whether the aggregated published research suggests that breast self examination is beneficial was explored in a meta-analysis of 12 studies including a total of 8118 patients with breast cancer that related the practice of breast self examination to regional lymph node state or tumour diameter. Based on the six studies for which data were available, 39% of patients (1115/2852) who reported having done breast self examination at least once before their illness had evidence of cancer in the lymph nodes compared with 50% of women (1348/2713) who had not done the examination. Logistic regression analysis showed this difference to be significant (odds ratio 0.66, confidence interval 0.59 to 0.74). Combining six studies which reported the circumstances of detection disclosed that 42% of women (272/652) who found their tumour while doing breast self examination had evidence of cancer in the nodes compared with 46% of women (871/1901) who found the tumour accidentally; this difference was not significant. Analysis of eight studies which used the diameter of the tumour to indicate the extent of disease tended to confirm the findings on lymph node state, in particular the benefit of premorbid breast self examination. Significantly fewer women who had practised the examination before the illness (56%; 1205/2137) had tumours of 2 cm or more diameter compared with women who had not practised the examination (66%; 1500/2260). The combined odds ratio for that analysis was 0.56, confidence interval 0.38 to 0.81. These findings appear to be good evidence of the benefit of encouraging women to practise self examination of the breasts regularly.