Association between dietary phytoestrogens intakes and prostate cancer risk in Sicily

Figures & data

Table 1. Baseline characteristics of cases and controls.

	Cases (n = 118)	Controls (n = 222)	p value
Age (y), mean (SD)	69.13 (6.60)	68.09 (8.18)	.19
BMI, mean (SD)	26.49 (3.34)	27.49 (3.28)	.30
Weight status, n (%)
Normal	42 (35.6)	59 (26.6)
Overweight	60 (50.8)	127 (57.2)
Obese	16 (13.6)	36 (16.2)
Smoking status, n (%)			.15
Non-smoker	68 (57.6)	143 (64.4)
Current smoker	50 (42.4)	79 (35.6)
Alcohol intake, n (%)			.16
<12 g/d	55 (46.6)	153 (68.9)
≥12 g/d	63 (53.4)	69 (31.1)
Education, n (%)			.11
Primary/secondary	96 (81.4)	49 (22.1)
High school/university	22 (18.6)	173 (77.9)
Physical activity level, n (%)			.21
Low	38 (32.2)	49 (26.2)
Medium	64 (54.2)	67 (35.8)
High	16 (13.6)	71 (38.0)
Family history of prostatic cancer, n (%)	43 (36.44)	9 (4.05)	<0.01

Table 2. Differences in mean consumption of phytoestrogens between cases and controls.

	Cases (n = 118)	Controls (n = 222)	p value
Lignans, mean (SD)	7.00 (5.43)	3.11 (2.70)	<.01
Isoflavones, mean (SD)	2.51 (10.51)	1.93 (8.75)	.59
Lariciresinol, mean (SD)	4.04 (3.29)	1.68 (1.64)	<.01
Matairesinol, mean (SD)	0.08 (0.06)	0.03 (0.03)	<.01
Pinoresinol, mean (SD)	2.28 (1.69)	1.06 (0.84)	<.01
Secoisolariciresinol, mean (SD)	0.26 (1.19)	0.12 (1.10)	<.01
Daidzein, mean (SD)	0.08 (0.24)	0.09 (0.33)	.88
Genistein, mean (SD)	0.08 (0.28)	0.08 (0.32)	.93
Glycitein, mean (SD)	0.02 (0.08)	0.01 (0.07)	.62
Biochanin A, mean (SD)	0.01 (0.002)	0.01 (0.003)	.32

Table 3. Association between quartiles of phytoestrogen intake and prostate cancer.

	Phytoestrogens quartiles, OR (95% CI)
	Q1	Q2	Q3	Q4
Lignans
No. of cases	14	8	10	86
OR (95% CI)^a	Ref.	0.51 (0.19–1.31)	0.57 (0.23–1.45)	4.72 (2.34–9.52)
OR (95% CI)^b	Ref.	0.37 (0.10–1.31)	0.70 (0.17–2.81)	9.31 (3.16–27.38)
Isoflavones
No. of cases	39	38	13	28
OR (95% CI)^a	Ref.	0.80 (0.44–1.45)	0.31 (0.15–0.65)	0.51 (0.27–0.96)
OR (95% CI)^b	Ref.	1.40 (0.58–3.40)	0.28 (0.10–0.77)	0.95 (0.39–2.33)
Lariciresinol
No. of cases	15	9	6	88
OR (95% CI)^a	Ref.	0.56 (0.22–1.41)	0.32 (0.11–0.93)	4.60 (2.32–9.11)
OR (95% CI)^b	Ref.	0.27 (0.08–0.98)	0.39 (0.08–2.00)	8.42 (2.94–24.13)
Matairesinol
No. of cases	17	7	16	78
OR (95% CI)^a	Ref.	0.38 (0.15–1.01)	0.80 (0.35–1.77)	3.63 (1.86–7.10)
OR (95% CI)^b	Ref.	0.31 (0.09–1.11)	1.02 (0.30–3.40)	6.49 (2.35–17.89)
Pinoresinol
No. of cases	12	8	13	85
OR (95% CI)^a	Ref.	0.60 (0.23–1.60)	0.98 (0.40–2.40)	5.62 (2.70–11.70)
OR (95% CI)^b	Ref.	0.54 (0.14–2.08)	1.45 (0.39–5.46)	12.77 (4.14–39.36)
Secoisolariciresinol
No. of cases	16	8	10	84
OR (95% CI)^a	Ref.	0.44 (0.17–1.12)	0.50 (0.20–1.23)	4.10 (2.10–8.10)
OR (95% CI)^b	Ref.	0.23 (0.06–0.81)	0.50 (0.13–1.96)	6.30 (2.25–17.60)
Daidzein
No. of cases	38	39	11	30
OR (95% CI)^a	Ref.	0.81 (0.45–1.46)	0.39 (0.18–0.87)	0.45 (0.24–0.83)
OR (95% CI)^b	Ref.	1.22 (0.51–2.92)	0.32 (0.11–0.94)	0.71 (0.30–1.67)
Genistein
No. of cases	35	46	12	25
OR (95% CI)^a	Ref.	0.97 (0.54–1.75)	0.42 (0.19–0.93)	0.40 (0.21–0.77)
OR (95% CI)^b	Ref.	1.43 (0.60–3.40)	0.33 (0.11–0.97)	0.60 (0.25–1.48)
Glycitein
No. of cases	110	8
OR (95% CI)^a^,c	Ref.	0.52 (0.21–1.31)	–	–
OR (95% CI)^b^,c	Ref.	0.46 (0.15–1.48)	–	–
Biochanin A
No. of cases	42	20	56
OR (95% CI)^a^,d	Ref.	0.59 (0.32–1.10)	1.66 (0.97–2.83)	–
OR (95% CI)^b^,d	Ref.	0.40 (0.16–0.99)	1.39 (0.63–3.08)	–

Q: quartile; OR: odds ratio.

^a ORs were adjusted for energy intake (kcal/d, continuous).

^b ORs were adjusted for age (years, continuous), energy intake (kcal/d, continuous), weight status (normal, overweight, obese), smoking status (smokers, non-smokers), alcohol consumption (<12 g/d, ≥12 g/d), physical activity level (low, medium, high) and family history of prostatic cancer;.

^c Due to the low number of cases and low amount of compound consumed, individuals were divided into two quantiles (less and more than median intake).

^d Due to the low number of cases and low amount of compound consumed, individuals were divided into tertiles.

Table 4. Association between quartiles of phytoestrogen intake and advanced prostate cancer.

	Phytoestrogens quartiles, OR (95% CI)^a
	Q1	Q2	Q3	Q4
Isoflavones	Ref.	0.47 (0.13–1.73)	0.13 (0.15–1.09)	0.01 (0.00–1.97)
Lignans^a	Ref.	0.97 (0.15–6.26)	–	–
Lariciresinol^b	Ref.	1.08 (0.17–6.99)	–	–
Matairesinol^b	Ref.	0.90 (0.13–6.14)	–	–
Pinoresinol^c	Ref.	0.48 (0.03–8.47)	2.47 (0.25–23.90)	–
Secoisolariciresinol^b	Ref.	0.72 (0.09–5.29)	–	–
Daidzein	Ref.	0.43 (0.11–1.58)	0.17 (0.02–1.49)	0.01 (0.00–1.81)
Genistein	Ref.	0.66 (0.18–2.32)	0.20 (0.02–1.74)	0.01 (0.00–1.75)
Biochanin A	Ref.	2.50 (0.22–28.22)	12.46 (1.52–101.87)	1.00 (1.00–1.00)

Q: quartile; OR: odds ratio.

^a ORs were adjusted for energy intake (kcal/d, continuous).

^b Due to the low number of cases and low amount of compound consumed, individuals were divided into two quantiles (less and more than median intake).

^c Due to the low number of cases and low amount of compound consumed, individuals were divided into tertiles.