Cigarette smoking, cytochrome P4501A1 polymorphisms, and breast cancer among African-American and white women

Table 6 Odds ratios (ORs) for breast cancer and smoking in relation to the CYP1A1 genotype at the M3 locus (African-American women only)

	M3 genotypes^a		wt genotype^b
	Cases/controls	OR (95% CI)^c	Cases/controls	OR (95% CI)^c
Active smoking status
Never	24/32	Referent	124/134	Reference
Former	16/11	1.9 (0.7–4.8)	58/42	1.7 (1.1–2.7)
Current	7/10	0.9 (0.7–2.8)	36/51	0.8 (0.5–1.3)
Number of cigarettes (pack/day)
Never	24/32	Referent	124/134	Reference
≤ 1	18/16	1.5 (0.6–3.5)	79/82	1.2 (0.8–1.7)
> 1	5/5	1.2 (0.3–4.7)	14/11	1.6 (0.7–3.8)
Duration of smoking
Never	24/32	Referent	124/134	Reference
≤ 20 years	8/13	0.8 (0.3–2.2)	54/55	1.2 (0.7–1.8)
> 20 years	15/8	2.5 (0.9–7.1)	39/37	1.3 (0.8–2.2)
Former smokers: time since cessation of smoking
Never	24/32	Referent	124/134	Reference
< 10 years	13/4	4.2 (1.2–14.6)	32/13	3.1 (1.5–6.1)
≥ 10 years	3/7	0.5 (0.1–2.3)	26/29	1.1 (0.6–2.0)
Age started smoking
Never	24/32	Referent	124/134	Reference
< 18 years	12/6	2.4 (0.8–7.5)	33/29	1.3 (0.7–2.3)
≥ 18 years	11/15	1.0 (0.4–2.5)	61/64	1.2 (0.8–1.8)

CI, confidence interval; wt, wild type. ^a M3/M3 and M3/wt genotypes. ^b wt/wt genotype. ^cAdjusted for age and sampling fractions.