Table 1: Detection/Induction Ratios for Breast Cancer Incidence by Age Group (from Law et al. 2007).

	No Family History		Positive Family History (index patient diagnosed between 30 and 39 years of age)
Age at Exposure (years)	EAR (Preston)	NRPB-2003	EAR (Preston)	NRPB-2003
25-29			4.2	4.4
30-34	3.3	2.9	18	16
35-39	10	7.0	50	34
40-44	25	13	87	46
45-49	56	24	124	53

Assumptions: Based on 4.5 mGy mean glandular dose, two views, annual screening. Abbreviations and references: EAR – excess absolute risk model (as apposed to the ERR – excess relative risk); NRPB – National Radiation Protection Board¹¹; Preston – from an international pooled analysis by Preston et al.¹²