Abstract: . . .  48 predicted a 15% reduction in mortality from breast cancer by 2004 among women who were aged 50–64 years when they were screened. These estimates were based on screening performance during the second round of screening, when the detection rates for small invasive cancers were still relatively low and the interval cancer rates were relatively high. 7 Furthermore, many factors have contributed to the decline in breast cancer mortality in England over the last decade, and the relevance of prognostic markers may be changing. Another approach is to estimate future breast cancer mortality in the absence of screening and use the restricted age range over which screen- 5.3 Impact of the NHSBSP on mortality from breast cancer Page 26 Screening for Breast Cancer in England: Past and Future NHSBSP February 2006 20 ing will affect mortality to estimate its effect, at the same time allow- ing for other factors. Blanks et al 21 used such an approach, fitting age cohort models and carrying out a detailed examination of age specific observed and expected mortality rates from breast cancer in England and Wales. They estimated that screening by the NHSBSP between 1988 and 1995 had resulted in a 6% reduction in mortality from breast cancer in women aged 55–69 years by 1998. 21 This comparatively low estimate of the reduction in mortality from breast cancer attributable to screening is in part because 1998 is only a few years after 1995, when full population coverage of the NHSBSP was first achieved, and in part because many deaths in the target age groups were among women who had been diagnosed with breast cancer before the age of 50. Blanks et al 21 concluded that the full effect of screening on mortalit . . .
--3000,1,1500,1802,54514