Table 4.

Odds ratios for breast cancer and total PCBs in relation to CYP1A1 M4 genotypes in white women

Total PCBsa	CYP1A1 M4 genotype	All participants		Premenopausal		Postmenopausal
		Patients/controls	OR (95% CI)b	Patients/controls	OR (95% CI)b	Patients/controls	OR (95% CI)b
<0.349	Non-M4	202/159	Referent	132/103	Referent	70/56	Referent
≥0.349	Non-M4	139/163	0.7 (0.5–1.0)	46/48	0.8 (0.5–1.2)	93/115	0.7 (0.4–1.1)
<0.349	Any M4	19/19	0.8 (0.4–1.6)	17/11	1.2 (0.5–2.7)	2/8	0.2 (0.0–0.9)
≥0.349	Any M4	14/17	0.7 (0.3–1.6)	5/5	0.8 (0.2–2.9)	9/12	0.7 (0.3–1.7)
ICR (95% CI)			0.2 (-0.6,1.0)		-0.1 (-1.6,1.3)		0.8 (0.1,1.5)

^aLipid-adjusted total imputed PCBs (ng/ml).

^bOdds ratios adjusted for age and sampling fractions.

Any M1, M1/M1 or M1/non-M1; CI, confidence interval; ICR, interaction contrast ratio; non-M1, non-M1/non-M1.