Table 2.

Standardized Incidence Ratio and Absolute Excess Risk of Subsequent Breast Cancer among Female Childhood Cancer Survivors of European Ancestry, Overall and by Polygenic Risk Score Quintile

PRS Quintiles	Observed	Expected	SIR	AER per 1,000 person years
1	6	2.1	2.9 (1.0 – 6.3)	0.7 (0.0 – 2.0)
2	6	1.9	3.4 (1.2 – 7.3)	0.8 (0.1 – 2.1)
3	14	2.1	6.6 (3.6 – 11.0)	2.3 (1.1 – 4.1)
4	10	1.7	5.9 (2.8 – 10.9)	1.7 (0.6 – 3.3)
5	19	2.0	9.4 (5.7 – 14.7)	3.2 (1.8 – 5.2)
Overall	55	9.7	5.7 (4.3 – 7.4)	1.7 (1.2 – 2.4)