Figure 7.3 summarises the recall rate, biopsy rate etc. for the UK Breast Screening programme. It shows that, for 100,000 women invited for screening, 2,522 women (3,105 recalled minus the 583 diagnosed with cancer =2,522) were recalled and found not to have cancer. This is called a false positive result (i.e. 3.36 % of all the women screened). Of the women recalled and found not to have cancer, the majority (1,744/2,522 = 69 %) had only further imaging (mammography, ultrasound etc.) but a minority (778/2,522 = 31 %) had a biopsy. This was core biopsy under local anaesthetic in all except 2.3 % (57/2,522) who had an open biopsy under general anaesthetic. The latter group represents only 0.076 % (57/75,057) of all women screened.

There are psychological effects of a false-positive result on women but the studies show conflicting results. A recent systematic review of the literature [3] concluded that, in the population at general risk of breast cancer, a false-positive result can cause breast cancer specific psychological distress which may endure for up to 3 years. The degree of distress is associated with the level of invasiveness of subsequent assessment. Some studies found that the distress caused by a false-positive result deterred some women from re-attending for breast screening which would reduce any benefit they would otherwise have got from being offered screening in the first place. The level of distress can be mitigated by providing women with clearly worded information about the recall and appropriate support from clinical staff before and during assessment [3]. Further information about caring for patients and clients can be found in Part II of this book.