Table 2.

Serum levels of lipophilic POPs (μg/kg lipid) in breast cancer cases and controls

Parameters	% > DL	Cases				Controls				p-value a	Age adjusted p-value b
		n	Median	P25-P75	Min-Max	n	Median	P25-P75	Min-Max
∑PCB		76	1467.34	549.82–2965.41	116.40–9288.90	84	1156.90	302.20–2170.81	43.60–6902.20	0.011	0.114
∑PCB Grp1		76	132.25	53.25–249.66	12.50–1103.00	84	103.50	32.88–182.76	3.90–470.29	0.007	0.696
∑PCB Grp2		76	481.05	178.34–903.06	37.00–2128.90	84	352.65	101.68–749.23	13.90–1763.53	0.022	0.211
∑PCB Grp3		76	815.66	324.75–1838.50	66.90–6057.00	84	655.13	179.01–1192.76	23.40–4789.00	0.008	0.084
∑DL-PCB		76	124.22	40.35–241.86	9.00–527.17	84	96.50	33.50–186.67	3.60–439.85	0.047	0.386
PCB99	96.9	76	56.57	28.00–106.97	3.50–315.22	84	53.00	14.75–82.94	2.00–182.21	0.022	0.161
PCB101	53.6	76	4.62	2.53–8.66	1.50–39.58	84	4.63	2.50–9.30	0.75–45.20	0.794	0.478
PCB105	92.1	76	10.40	3.93–23.36	1.00–80.43	84	5.53	3.05–19.79	0.50–48.38	0.175	0.797
PCB118	88.1	76	69.18	24.00–146.98	5.70–369.57	84	58.00	20.75–107.85	2.60–242.65	0.039	0.300
PCB138	100.0	76	212.53	100.00–452.31	20.00–970.00	84	190.75	47.00–377.74	7.00–990.59	0.018	0.169
PCB153	100.0	76	486.36	185.00–1075.00	40.00–3100.00	84	375.00	98.61–666.83	14.00–2400.00	0.006	0.070
PCB156	98.0	76	34.50	11.11–68.77	1.89–270.00	84	20.71	6.03–53.50	0.50–217.79	0.057	0.516
PCB170	100.0	76	84.02	33.23–211.20	5.85–900.00	84	73.00	18.25–150.00	2.80–650.00	0.022	0.227
PCB180	100.0	76	266.36	98.41–637.61	20.75–2800.00	84	200.59	56.50–411.95	6.90–2200.00	0.009	0.104
PCB183	98.0	76	24.00	12.21–52.37	2.40–130.00	84	22.53	7.32–38.22	0.50–91.76	0.012	0.111
PCB187	100.0	76	122.36	50.50–240.43	9.00–1100.00	84	95.50	28.96–167.77	1.90–463.85	0.012	0.111
∑OCP		76	1933.96	752.60–3785.71	160.70–9765.00	84	1529.79	438.70–2405.10	53.35–6334.00	0.004	0.042
Cis-Nonachlor	99.3	76	65.00	23.00–128.75	6.20–228.26	84	50.53	18.00–92.80	0.35–190.00	0.008	0.077
Trans-Nonachlor	99.3	76	355.56	130.39–827.21	35.00–1700.00	84	276.30	86.00–475.79	0.50–980.00	0.005	0.054
HCB	100.0	76	190.00	73.00–362.17	20.00–693.18	84	135.00	56.94–255.26	10.00–686.63	0.030	0.241
Mirex	94.7	76	25.00	11.15–74.92	1.89–420.00	84	22.65	6.08–47.79	0.50–150.00	0.018	0.171
Oxychlordane	100.0	76	200.00	62.75–456.03	12.45–1100.00	84	138.86	40.42–290.63	1.00–730.00	0.010	0.096
p,p’DDE	100.0	76	950.00	415.00–1949.57	76.00–5800.00	84	779.20	232.50–1144.87	33.00–4100.00	0.002	0.024
p,p’DDT	69.3	75	20.00	7.00–34.00	3.00–132.61	84	10.00	4.50–26.97	2.99–86.76	0.112	0.356
βHCH	99.3	76	31.00	10.25–48.43	1.00–150.00	84	18.50	8.03–38.83	1.00–83.66	0.056	0.408

% > DL: % of samples above decetion limet; n: number of observations per group; P25-P75: 25 percentile – 75 percentile; ^a p-value for the difference between cases and controls tested on ln-transformed variables with independent samples t-test; ^b p-value for the difference between cases and controls when adjusting for age, tested with ANCOVA test with age as a covariate factor; Bold text: significant finding; ∑PCB: PCB 99, 101, 105, 118, 128, 138, 153, 156, 170, 180, 183, 187; ∑PCB group 1 (estrogenic PCBs): PCB 101, 187; ∑PCB group 2 (anti-estrogenic and dioxin-like PCBs): PCB 105, 118, 128, 138, 156, 170; ∑PCB group 3 (CYP1A1 and CYP2B inducing PCBs): PCB 99, 153, 180, 183; ∑DL-PCBs (dioxin-like PCBs): PCB 105, 118, 156; ∑OCP: p,p′-DDT, p,p′-DDE, mirex, β-HCH, HCB, cis- and trans-nonachlor, and oxychlordane. The serum concentration of the POPs was reported in μg/kg lipid