Validation of the Gail model for predicting individual breast cancer risk in a prospective nationwide study of 28,104 Singapore women

Table 2 Relative risks of total breast cancers based on Singapore Breast Cancer Screening Project cohort by risk factors in Gail model

Risk factors	Based on SBCSP (95% CI)	Gail model: BCDDP (95% CI)
Age at menarche, years
≥14	1.00 (referent)	1.00 (referent)
12-13	1.39	1.10
< 12	1.95	1.21
Any breast biopsy Age at screening: ≥50 years
No	1.00 (referent)	1.00 (referent)
Yes	1.97	1.28^a
Number of affected first-degree relatives Age at first live birth: < 20 years
0	1.00 (referent)	1.00 (referent)
1	3.61	2.61
> 1	13.04	6.80
Number of affected first-degree relatives Age at first live birth: 20-24 years
0	1.33	1.24
1	4.14	2.68
> 1	12.91	5.78
Number of affected first-degree relatives Age at first live birth: 25-29 years or nulliparous
0	1.76	1.55
1	4.75	2.76
> 1	12.79	4.91
Number of affected first-degree relatives Age at first live birth: > 30 years
0	2.34	1.93
1	5.44	2.83
> 1	12.67	4.17

^aDerived from Decarli and colleagues [23] (2006). BCDDP, Breast Cancer Detection Demonstration Project; CI, confidence interval; SBCSP, Singapore Breast Cancer Screening Project.

ISSN: 1465-542X