Table 4. Effect Modification of PhIP-DNA Adduct Level^a Associations with Prostate Cancer.

	Whole Sample (n=534 case-control pairs)			African Americans (n=213 case-control pairs)			Whites (n=321 case-control pairs)
Effect Modifier	OR	95% CI	P value	OR	95% CI	P value	OR	95% CI	P value
PSA at cohort entry
PSA<4 ng ml/Low PhIP	1			1			1
PSA<4 ng ml/High PhIP	1.35	0.79-2.32	0.27	0.89	0.35-2.27	0.81	1.63	0.84-3.18	0.15
PSA≥4 ng ml/Low PhIP	3.39	2.14-5.36	<0.0001	3.73	1.83-7.62	0.0003	3.08	1.69-5.63	0.0002
PSA≥4 ng ml/High PhIP	3.21	2.00-5.15	<0.0001	2.37	1.08-5.19	0.03	3.62	1.99-6.58	<0.0001
PSA≥4 ng ml × High PhIP Interaction	0.70	0.39-1.27	0.24	0.71	0.26-1.93	0.51	0.72	0.34-1.52	0.39
Glandular Inflammation
No Inflammation/Low PhIP	1			1			1
No Inflammation/High PhIP	1.06	0.75-1.48	0.75	0.70	0.40-1.25	0.23	1.29	0.84-1.96	0.25
Inflammation/Low PhIP	0.78	0.48-1.27	0.32	1.01	0.49-2.07	0.98	0.64	0.32-1.26	0.20
Inflammation/High PhIP	1.54	0.91-2.61	0.11	1.56	0.54-4.52	0.42	1.61	0.87-2.99	0.13
Inflammation × High PhIP Interaction	1.87	0.95-3.68	0.07	2.19	0.65-7.43	0.21	1.97	0.83-4.69	0.13
HGPIN
No HGPIN/Low PhIP	1			1			1
No HGPIN/High PhIP	1.16	0.84-1.61	0.37	0.82	0.47-1.44	0.48	1.38	0.92-2.07	0.12
HGPIN/Low PhIP	2.16	1.07-4.37	0.03	2.88	1.04-7.98	0.04	1.52	0.55-4.16	0.42
HGPIN/High PhIP	2.25	1.12-4.51	0.02	0.79	0.24-2.59	0.69	3.89	1.56-9.73	0.004
HGPIN × High PhIP Interaction	0.90	0.35-2.28	0.82	0.33	0.08-1.46	0.15	1.86	0.50-6.88	0.35
Partial Atrophy
No Atrophy/Low PhIP	1			1			1
No Atrophy/High PhIP	1.23	0.87-1.74	0.25	0.85	0.47-1.53	0.58	1.48	0.95-2.30	0.08
Atrophy/Low PhIP	0.98	0.66-1.46	0.92	1.12	0.62-2.02	0.72	0.89	0.51-1.54	0.67
Atrophy/High PhIP	1.00	0.66-1.74	1.00	0.59	0.27-1.28	0.18	1.25	0.76-2.08	0.38
Atrophy × High PhIP Interaction	0.83	0.49-1.41	0.49	0.63	0.26-1.52	0.30	0.95	0.48-1.89	0.89

^aHigh PhIP was considered above median level in controls