Table 2.

The relative risk of breast cancer associated with testosterone levels: results from case–control studies

Author, year [reference]	Population	Exposure	Cases	Controls	Categories1	OR	95% CI	P
Secreto, 1984 [27]2	Premenopausal women in Milan	Serum T	13	47	<590	1.0
			4	9	590–670	2.6	0.6–10.9
			10	6	671+	10.2	2.6–40.0	0.0004
		Urinary T	9	35	<8.2	1.0
			4	7	8.2–10.5	2.3	1.2–12.9
			10	5	10.6+	8.4	2.1–33.6	0.002
Secreto, 1989 [28]2	Women in Milan age 30–49 years	Serum T	31	51	<309	1.0
			32	17	309+	3.4	1.6–7.3	0.05
		Urinary T	36	50	<7.6	1.0
			24	16	7.6+	2.1	0.9–4.8	NS
Secreto, 1991 [24]3	Postmenopausal women in Milan<69 years of age	Serum T	16	40	<146	1.0
			16	40	146–212	1.2	0.5–3.0
			18	38	213–275	1.5	0.6–3.7
			25	32	>275	2.7	1.1–6.7	0.03
		Urinary T4	11	43	<18	1.0
			14	38	18–31	1.2	0.5–2.9
			17	37	32–46	2.2	0.8–5.7
			30	26	>46	4.7	1.8–12.1	0.001
		Serum DHT	15	37	<36	1.0
			20	40	36–57	1.6	0.7–3.7
			16	38	58–82	1.3	0.5–3.1
			24	35	>82	2.0	0.8–5.0	NS
Lipworth, 1996 [25]5	Postmenopausal women from Sweden	Serum T6	23	35	260	1.00
			15	27	350	0.75	0.33–1.75
			47	30	470	2.64	1.27–5.46
			36	30	700	2.30	0.97–5.50	0.041

¹Serum T and DHT converted to pg/ml and urinary T converted to μg/24 hours. ²Age adjusted model. ³Adjusted for age, occupation and number of children. ⁴Units in pg/ml. ⁵Adjusted for age and residence. ⁶Categorized by quartile medians. CI, confidence interval; DHT, dihydrotestosterone; NS, not significant; OR, odds ratio; T, testosterone.