Table 2.

Diagnostic chest x-rays and breast cancer risk for non-Hispanic White women, by BRCA1 and BRCA2 mutation status

	BRCA1 mutation carriers				BRCA2 mutation carriers
	Cases N=167	Controls N=287	Multivariate adjusted OR (95% CI) a		Cases N=104	Controls N=169	Multivariate adjusted OR (95% CI) a
History of diagnostic chest x-rays
No chest x-rays	125	246	1.0		76	133	1.0
One or more chest x-rays	42	41	1.31	0.75–2.30	28	36	1.13	0.59–2.18
Chest fluoroscopy for tuberculosis	3	1	2.58	0.22–30	2	2	0.93	0.11–7.89
Chest x-rays for pneumonia	3	2	4.54	0.53–39	2	2	0.33	0.02–5.63
Other diagnostic chest x-rays	36	38	1.16	0.64–2.11	24	32	1.22	0.62–2.42
Other diagnostic chest x-rays b
Age at first chest x-ray (years)
No chest x-rays	125	246	1.0		76	133	1.0
<20	10	22	0.57	0.22–1.48	9	10	1.55	0.54–4.47
≥20	21	14	1.69	0.76–3.76	11	17	1.06	0.43–2.60
Unknown	5	2	2.58	0.42–15.8	4	5	1.12	0.24–5.26
Year of first chest x-ray
No chest x-rays	125	246	1.0		76	133	1.0
Before 1980	16	17	1.14	0.48–2.70	10	6	2.18	0.69–6.88
1980 or after	15	19	1.01	0.44–2.29	10	21	0.90	0.37–2.19
Unknown	5	2	2.62	0.43–16.0	4	5	1.10	0.24–5.12
Number of chest x-rays
No chest x-rays	125	246	1.0		76	133	1.0
1–2	11	16	0.84	0.33–2.13	7	15	0.80	0.28–2.28
3–5	8	6	1.22	0.35–4.21	9	2	10.63	1.93–58
≥6	6	7	1.20	0.37–3.96	3	3	0.89	0.15–5.49
Unknown	11	9	1.75	0.57–5.35	5	12	0.62	0.18–2.17

^aOdds ratio (OR) and 95% confidence interval (CI), adjusted for age, study site, family history of breast or ovarian cancer in first-degree relatives, and number of full-term pregnancies.

^bExcluding individuals with chest x-rays fluoroscopy for tuberculosis or chest x-rays for pneumonia.