Table 4. Associations of urinary phytoestrogen excretion with prostate cancer risk by race/ethnicitya.

	African Americans		Japanese Americans		Latinos		Whites
	Cases/controls	OR (95% CI)	Cases/controls	OR (95% CI)	Cases/controls	OR (95% CI)	Cases/controls	OR (95% CI)	P for interactionb
Daidzein
⩽0.234c	68/87	1.00	19/27	1.00	31/33	1.00	22/30	1.00
>0.234	24/46	0.75 (0.39–1.45)	51/95	0.71 (0.35–1.42)	13/35	0.38 (0.16–0.92)	15/40	0.47 (0.19–1.20)	0.65
Genistein
⩽0.067	64/91	1.00	16/26	1.00	30/37	1.00	23/31	1.00
>0.067	28/42	1.28 (0.69–2.38)	54/96	0.92 (0.44–1.95)	14/31	0.52 (0.23–1.21)	14/39	0.42 (0.17–1.06)	0.34
Equol
⩽0.004	53/77	1.00	33/66	1.00	17/35	1.00	12/26	1.00
>0.004	39/56	1.06 (0.53–2.11)	37/56	1.62 (0.80–3.28)	27/33	2.14 (0.76–6.03)	25/44	1.27 (0.48–3.37)	0.85
Daidzein+Genistein
⩽0.326	68/90	1.00	18/24	1.00	31/32	1.00	23/31	1.00
>0.326	24/43	0.84 (0.43–1.64)	52/98	0.63 (0.31–1.29)	13/36	0.37 (0.16–0.87)	14/39	0.41 (0.16–1.10)	0.54
Daidzein+Genistein
+Equol
⩽0.335	68/91	1.00	18/23	1.00	31/32	1.00	21/32	1.00
>0.335	24/42	0.90 (0.46–1.76)	52/99	0.61 (0.30–1.26)	13/36	0.32 (0.13–0.80)	16/38	0.56 (0.21–1.46)	0.55
Enterolactone
⩽1.091	44/63	1.00	47/72	1.00	19/35	1.00	12/23	1.00
>1.091	48/70	1.02 (0.54–1.94)	23/50	0.67 (0.34–1.31)	25/33	1.76 (0.74–4.19)	25/47	1.17 (0.47–2.92)	0.33

^aMatching for geographic location (Hawaii or California), race/ethnicity, birth year (±1 year), date (±6 months) and time (±2 h) of specimen collection, and fasting hours (0–<6, 6–<8, 8–<10, and 10+ h). The models were adjusted for age at specimen collection and fasting hours as continuous variables, as well as family history of prostate cancer, BMI, and education.

^bThe P for interaction between urinary phytoestrogen excretion and ethnicity is based on the likelihood ratio test.

^cExpressed as nmol mg⁻¹ creatinine.