Infertility and risk of breast cancer in men: a national case–control study in England and Wales

Breast Cancer Research

Table 5 Risk of invasive and in situ breast cancer in men in relation to infertility and number of children

	Invasive							In situ
	Cases No. %		Controls No. %		Odds ratio^a	(95% CI)	P	Cases No. %	Controls No. %	Odds ratio^a	(95% CI)	P
Infertility
No	1664	90.5	1503	94.1	1.00			146	1503	1.00
Yes	107	5.8	80	5.0	1.34	(0.97–1.85)	0.07	5	80	0.70	(0.28–1.79)	0.46
Not known	67	3.6	14	0.9	1.55	(0.79–3.02)	0.20	9	14	2.31	(0.88–6.10)	0.09
Source
Self	47	2.6	22	1.4	1.96	(1.13–3.41)	0.02	3	22	1.72	(0.50–5.94)	0.39
Partner	30	1.6	34	2.1	0.93	(0.55–1.58)	0.81	1	34	0.28	(0.04–2.09)	0.21
Not known	30	1.6	24	1.5	1.35	(0.75–2.44)	0.31	1	24	0.53	(0.07–3.98)	0.53
No. of children
0	353	19.2	174	10.9	1.00			30	174	1.00
≥ 1	1485	80.8	1423	89.1	0.65	(0.52, 0.81)	< 0.001	130	1423	0.87	(0.54, 1.41)	0.58
1	267	14.5	172	10.8	0.93	(0.69–1.24)	0.60	29	172	1.38	(0.76–2.52)	0.29
2	733	39.9	798	50.0	0.60	(0.48–0.76)	< 0.001	56	798	0.66	(0.39–1.12)	0.12
≥ 3	485	26.4	453	28.4	0.63	(0.49–0.81)	< 0.001	45	453	0.99	(0.57–1.71)	0.97
Linear trend per child, including 0					0.84	(0.78–0.91)	< 0.001			0.93	(0.78–1.12)	0.44
Linear trend per child, excluding 0					0.88	(0.78–0.99)	0.04			0.95	(0.71–1.26)	0.71
Total	1838	100.0	1597	100.0				160	1597

CI, confidence interval
^aAdjusted for age, socio-economic status (Acorn score [20]), year of interview, marital status and geographical region of residence

ISSN: 1465-542X