. Author manuscript; available in PMC: 2010 Nov 1.

Published in final edited form as: Cancer Causes Control. 2009 Nov;20(9):1733–1737. doi: 10.1007/s10552-009-9425-9

Table 1.

Risk of breast cancer in relation to family history of breast cancer

Participant's age (years)	First-degree family history	Breast cancer cases	Person-years	Age-adjusted incidence rate ratio (95% CI)	Multivariable incidence rate ratio (95% CI)
<35	No	56	134,325	1.00	1.00
	Yes	10	7,812	2.77 (1.41-5.45)	2.76 (1.40-5.43)
35-44	No	289	180,741	1.00	1.00
	Yes	53	16,311	1.93 (1.44-2.59)	1.93 (1.44-2.60)
45-54	No	382	141,747	1.00	1.00
	Yes	85	17,066	1.81 (1.43-2.30)	1.81 (1.43-2.29)
≥ 55	No	350	83,921	1.00	1.00
	Yes	81	12,302	1.60 (1.25-2.03)	1.60 (1.25-2.04)
Overall	No	1,077	540,734	1.00	1.00
	Yes	229	53,491	1.79 (1.55-2.06)	1.78 (1.55-2.06)