Mammography screening in elderly women: efficacy and cost-effectiveness.

The definition of an upper age limit for breast cancer screening is a rather complex issue, influenced by several conditions. Randomised trials specifically designed to investigate this aspect are not available, but all process indicators (positive predictive value, length of sojourn time, sensitivity of the test) indicate that screening efficacy does not change with increasing age. On the other hand, competing causes of death could decrease screening efficacy beyond age 74. Screening benefits depend on life expectancy and people with <5-10 years life expectancy are unlikely to benefit from screening, so it is still worthwhile considering the variability of life expectancy at different ages. Furthermore, economical implications are evident. Public health recommendations need to weigh the benefit of screening elderly women against costs, negative side effects and potential harm due to overdiagnosis and overtreatment of screen-detected lesions expected to have no effect on mortality. In this scenario, the medical system has an ethical obligation to properly inform the population invited to screening. Over the age of 74 years, encouraging individualized decisions may be more appropriate and may indicate further screening for those subjects for whom the potential benefit outweighs the potential negative effects.