Publicity of NHS breast cancer screening programme is unfair

More informative information for women on the benefits and harms of mammographic screening has been sought for a long time.1 2 In December 2010 a revised leaflet finally appeared, but it is still misleading.3

The benefits cited are based on the programme’s own review. On the basis of a 35% reduction in death rate among screened women, it estimates that 1347 deaths from breast cancer are prevented each year. But the recent US Preventive Services Task Force, based on all randomised trials, reports a 14% reduction in women aged 50-59 and 32% in those aged 60-70. Further, a Cochrane review argues that taking account of the likely biases in the trials, a 15% reduction overall is more plausible, leading to nearer 500 fewer deaths a year, not 1400. The estimate of the number of women who need to be screened over 10 years to prevent one death (400 in the leaflet) is also far too low; it is 1000 if the effect is 30% and 2000 if the effect is 15%.4 5

The leaflet also completely fails to pay enough attention to harm, although the chance of overdiagnosis may be higher than that of preventing death. General Medical Council guidelines say both should be communicated; women have a right to know, even if focus groups may advise against.