Safe or sorry? Cancer screening and inductive risk

The general assumption behind cancer screening has been that early diagnosis and treatment is effective at reducing cancer-related mortality; this is broadly speaking true, for some cancer screening efforts, in some age groups. However, screening may in some cases do more harm than good. One source of harm is overdiagnosis and overtreatment, the diagnosis and treatment of indolent or slow-growing disease that may never lead to morbidity or mortality in the lifetime of the patient. Precaution in cancer screening is thus a double-edged sword: early diagnosis and treatment has clear benefits; but it is also true that some percentage of patients is unnecessarily treated. This chapter will examine how inductive risk and values come into play in debates about mammography screening.