Screening for breast cancer.

Clearly breast cancer in women aged over 50 fulfils the first two criteria, but it is the third point that is inconsistent with the 3-yearly programme proposed in the UK. The ‘sojourn’ time is the duration of time that an occult tumour can be detected before the onset of symptoms. Applying this to breast cancer (for the average non-screening-detected breast cancer of 1 2 cm) it has been estimated as 3.3 years in women aged 50 59 years. It is therefore illogical to propose 3-yearly screening in this age group, and 2-yearly mammograms and yearly clinical examination would be more suitable.