Table 1.

Women unaffected by breast cancer at entry with DNA collected by combined 10-year risk groups

10-year risk group	< 1.5%a	< 2%	2–3.49%	3.5–4.9%	5–7.9%	8% +	Total
Total in group	1596	3003	3038	1587	1129	605	9362
BC before sampling	23	59	87	76	45	33	300
Number in prospective group	1573	2944	2951	1511	1084	572	9062
% in Group	17.36%	32.49%	32.56%	16.67%	11.96%	6.31%	100.00%
Prospective BC number	10	26	52	39	36	42	195
Prospective DCIS	2 (20%)	4 (15.4%)	8 (15.4%)	5 (12.8%)	5 (13.9%)	4 (9.5%)	26 (13.3%)
Stage 2+	2 (20%)	8 (30.8%)	13 (25%)	13 (33.3%)	17 (47.2%)	16 (38.1%)	68 (34.9%)
% with prospective BC/total	0.64%	0.88%	1.76%	2.58%	3.32%	7.34%	2.15%
% of all stage 2+ cancers	2.9%	10.3%	19.1%	19.1%	23.5%	25%
Years of follow-up	9845.9	18361.8	18263.7	9304.1	6645.8	3482.1	56057.6
Expected BC by TCDRSNP	11.17	26.14	48.61	38.52	40.89	41.36	195.51
Expected BC by TC	21.23	42.89	54.39	34.04	30.44	22.51	184.27
Rate 10-year	1.02%	1.42%	2.85%	4.19%	5.42%	12.06%	3.48%
Rate 10-year Stage 2+	0.2%	0.43%	0.71%	1.39%	2.55%	4.59%
OR of stage 2+ incidence	Ref	2.15	3.55	6.95	12.75	22.95

^aThe 1.5% risk group includes women also in the < 2% group to assess which is the better low-risk threshold