Table 1.

Distribution of PCBs in breast cancer controls and cases

Classification [24]	PCB	Controls (N = 117)			Cases (N = 123)			Difference within matched pairs (case–control, N = 112)		Percent > LOD
		Percentile (mmol/l)			Percentile (mmol/l)
		25th	50th	75th	25th	50th	75th	Mean (mmol/l)	p value
Estrogenic	101	0.37	0.74	1.07	0.34	0.55	0.92	−0.06	0.19	89
	187	0.38	0.48	0.66	0.38	0.48	0.63	−0.07	0.30	100
	201	0.09	0.23	0.33	0.14	0.23	0.30	−0.01	0.71	71
Anti-estrogenic
A. Non-ortho, mono-ortho, dioxin-like	66	0.89	1.34	1.78	0.96	1.47	1.95	0.10	0.17	99
	74	0.62	0.89	1.23	0.62	0.86	1.27	0.01	0.54	95
	105	0.25	0.40	0.64	0.25	0.43	0.61	−0.01	0.92	81
	118	1.19	1.62	2.02	1.19	1.53	2.11	−0.03	0.94	100
	156	0.11	0.28	0.42	0.11	0.28	0.39	−0.03	0.68	64
	167	0.08	0.19	0.30	0.08	0.14	0.25	−0.03	0.12	49
B. Di-ortho, limited dioxin activity	138	1.58	2.05	2.55	1.50	2.02	2.77	−0.09	0.56	100
	170	0.30	0.46	0.66	0.35	0.48	0.63	−0.01	0.74	97
Phenobarbital, CYP1A, and CYP2B inducers	99	0.28	0.58	0.80	0.25	0.52	0.86	−0.04	0.30	83
	153	1.88	2.38	3.08	1.86	2.43	3.08	−0.08	0.40	100
	180	0.89	1.21	1.54	0.94	1.21	1.57	0.01	0.63	100
	183	0.13	0.23	0.35	0.10	0.23	0.33	−0.03	0.32	66
	203	0.21	0.30	0.42	0.23	0.35	0.47	0.02	0.20	90
	203/167 + 187	0.34	0.43	0.52	0.38	0.50	0.63	0.09	NA	NA

Variable number of subjects in each group is due to missing data on one or more of the PCB congeners shown. The PCB score (PCB 203/(PCB 187 + PCB 167)) was based on the best fitting model as described in the text, and is provided to describe the distribution of the mixture of significant PCB predictors. p values are not presented for the PCB score because the score was created after analysis, as described in text. p values shown are for Wilcoxon Signed Rank Test of differences (case–control) within age-matched case–control pairs

LOD limit of detection