Table 1. Breast cancer risk estimates according to mutation carrier probabilities.

	Mixed approach as in Geoffroy-Perez et al (2001)						A priori carrier probabilities						Corrected mixed approach as proposed by Olsen et al (2005)
Female relative	No.	PY	Obs	Exp	SIR	95% CI	No.	PY	Obs	Exp	SIR	95% CI	No.	PY	Obs	Exp	SIR	95% CI
ALL	711	33 002.12	28	19.26	1.45	0.97–2.10
Mutation carrier probability
1	115	5075.3	9	2.32	3.88	1.77–7.36	41	1848.6	3	0.67	4.48	0.90–13.1	44	2030.3	4	0.78	5.13	1.38–13.1
0.5	198	8764.9	5	5.19	0.96	0.31–2.25	199	8895.8	8	4.44	1.80	0.78–3.55	318	13 823.0	9	7.52	1.20	0.55–2.27
0.25	108	5403.7	3	3.27	0.92	0.18–2.68	353	17 511.5	14	12.27	1.14	0.62–1.91	155	8365.1	10	5.52	1.81	0.87–3.33
0.125	5	194.4	0	0.06	—		102	3611.9	3	0.97	3.09	0.62–9.04	8	281.7	0	0.06	—
0	285	13 563.8	11	8.42	1.31	0.65–2.34	16	1134.3	0	0.91	—		186	8502.1	5	5.38	0.93	0.30–2.17
			Weighted SIR		2.42	1.32–4.06					2.67	1.53–4.32					2.54	1.42–4.18
Mother	37	1559.5	3	0.42	7.14	1.44–20.9
Other carrier female relatives	78	3515.8	6	1.90	3.16	1.15–6.87	4	289.1	0	0.24	—		7	470.7	1	0.35	2.86	0.04–15.9

CI=confidence interval; SIR=standardised incidence ratio; PY=person-years.