Familial relative risks for breast cancer by pathological subtype: a population-based cohort study

Breast Cancer Research

Table 3 Age-specific familial relative risk for breast cancer by ER status of the index case tumour

Age of relative (years) †	ER-negative				ER-positive				All cases
	OBS	EXP	FRR	95%CI	OBS	EXP	FRR	95%CI	OBS	EXP	FRR	95%CI
Index case <50*
<50†	26	7.65	3.40	2.04-4.75	60	22.21	2.70	2.01-3.39	129	50.62	2.55	2.09-3.01
50 to 84	21	14.77	1.42	0.81-2.03	84	50.3	1.67	1.32-2.02	186	113.76	1.64	1.33-1.95
0 to 84	47	22.43	2.10	1.48-2.71	144	72.51	1.99	1.65-2.32	315	164.37	1.92	1.70-2.13
Index case >= 50
<50	22	8.59	2.56	1.31-3.81	75	43.57	1.72	1.33-2.11	160	82.16	1.95	1.63-2.56
50 to 84	52	37.04	1.40	1.01-1.80	339	190.09	1.78	1.59-1.98	604	359.53	1.68	1.54-1.82
0 to 84	74	45.63	1.62	1.22-2.02	414	233.66	1.77	1.59-1.95	764	441.69	1.73	1.60-1.86
Index case any age
<50	48	16.24	2.96	2.04-3.87	135	65.78	2.05	1.70-2.40	289	132.78	2.18	1.92-2.44
50 to 84	73	51.82	1.41	1.08-1.74	423	240.39	1.76	1.59-1.93	790	473.28	1.67	1.54-1.80
0 to 84	121	68.06	1.78	1.44-2.11	558	306.17	1.82	1.67-1.98	1079	606.06	1.78	1.68-1.89

CI: Confidence Interval; ER; estrogen receptor; EXP: expected; FRR: familial relative risk; OBS: observed.
* age at which index is affected
† age of relative (years) <50: relatives were followed up from birth up until censoring or age 50, whichever occurred first, 50 to 84: from age 50 to censoring, 0 to 85: from birth to censoring

ISSN: 1465-542X