Fiber intake and endometrial cancer risk

Figures & data

Table I. Distribution of 454 cases of endometrial cancer and 908 controls according to selected variables. Italy, 1992–2006.

	Cases		Controls
Characteristic	No.	(%)	No.	(%)
Age (years)
<40	19	(4.2)	38	(4.2)
40–44	12	(2.6)	24	(2.6)
45–49	36	(7.9)	72	(7.9)
50–54	59	(13.0)	118	(13.0)
55–59	81	(17.8)	162	(17.8)
60–64	84	(18.5)	167	(18.4)
65–69	82	(18.1)	165	(18.2)
≥70	81	(17.8)	162	(17.8)
Centre
Pordenone	237	(52.2)	474	(52.2)
Milano	140	(30.8)	280	(30.8)
Napoli	77	(17.0)	154	(17.0)
Education (years)
<7	263	(57.9)	553	(60.9)
7–11	119	(26.2)	225	(24.8)
≥12	72	(15.9)	130	(14.3)
χ^22=1.18; p=0.56
Body Mass Index (kg/m^2)^a
<21	24	(5.3)	106	(11.7)
≥21–<25	102	(22.5)	307	(34.0)
≥25–<30	160	(35.2)	351	(38.8)
≥30	168	(37.0)	140	(15.5)
χ^23=85.68; p<0.001
Menopausal status^a
Pre/peri	85	(19.2)	174	(19.3)
Post	358	(80.8)	726	(80.7)
χ^21=0.004; p=0.95
Parity
Nulliparous	68	(15.0)	126	(13.9)
Parous	386	(85.0)	782	(86.1)
χ^21=0.30; p=0.58
Oral contraceptive use
No	408	(89.9)	790	(87.0)
Yes	46	(10.1)	118	(13.0)
χ^21=2.34; p=0.13
Hormone replacement therapy use
No	405	(89.2)	830	(91.4)
Yes	49	(10.8)	78	(8.6)
χ^21=1.74; p=0.19

^aThe sum does not add up to the total because of missing value.

Table II. Odds ratios (OR)^a of endometrial cancer and corresponding 95% confidence intervals (CI) according to the intake of various types of fiber. Italy, 1992–2006.

			Quintile, OR (95% CI)
Nutrient	Mean^b	Standard deviation	1 (lowest)	2	3	4	5 (highest)	χ^2 trend (p-value)	OR (continuous)^d
Total (Englyst) fiber	15.3	5.2	1	1.3 (0.9–1.9)	1.0 (0.7–1.5)	1.0 (0.7–1.4)	1.1 (0.7–1.6)	0.24 (0.62)	0.96 (0.86–1.07)
Soluble NCP	7.7	2.5	1	1.1 (0.7–1.5)	0.7 (0.5–1.0)	1.1 (0.7–1.6)	0.7 (0.5–1.1)	1.79 (0.18)	0.92 (0.83–1.03)
Total insoluble fiber	7.6	3.6	1	0.9 (0.6–1.3)	0.9 (0.6–1.3)	0.8 (0.6–1.2)	1.0 (0.7–1.5)	0.03 (0.86)	0.94 (0.85–1.05)
Cellulose	3.6	1.9	1	1.1 (0.8–1.6)	1.3 (0.9–2.0)	1.1 (0.7–1.6)	0.9 (0.6–1.3)	0.19 (0.67)	0.97 (0.87–1.08)
Insoluble NCP	4.0	1.5	1	0.9 (0.6–1.3)	0.9 (0.6–1.3)	1.2 (0.8–1.8)	0.9 (0.6–1.3)	0.01 (0.89)	1.03 (0.92–1.15)
Lignin	1.5	0.5	1	0.7 (0.5–1.1)	0.8 (0.5–1.1)	0.7 (0.5–1.0)	0.6 (0.4–0.9)	4.21 (0.04)	0.88 (0.79–0.98)
Vegetable fiber	5.7	2.2	1	1.1 (0.7–1.6)	1.0 (0.7–1.5)	1.0 (0.7–1.4)	0.9 (0.6–1.3)	0.66 (0.42)	0.98 (0.88–1.09)
Fruit fiber	5.8	3.6	1	1.0 (0.7–1.4)	1.0 (0.7–1.4)	0.9 (0.6–1.3)	0.8 (0.5–1.1)	1.53 (0.22)	0.94 (0.84–1.05)
Grain fiber	4.5	2.1	1	0.9 (0.6–1.3)	1.1 (0.7–1.6)	0.9 (0.6–1.3)	1.1 (0.7–1.6)	0.05 (0.83)	0.98 (0.88–1.11)

^aEstimates from conditional logistic regression, conditioned on centre, and age, and adjusted for period of interview, body mass index, physical activity, education, smoking, alcohol consumption, age at menarche, parity, menopausal status, oral contraceptive use, hormone replacement therapy use, diabetes, and total energy intake, according to the residual method.

^bg/day, among controls;

^cReference category;

^dOR relative to 1 standard deviation among controls.

Table III. Odds ratios (OR)^a,b of endometrial cancer and corresponding 95% confidence intervals (CI) according to the intake of various types of fiber, in strata of body mass index (BMI), menopausal status and hormone replacement therapy (HRT) use. Italy, 1992–2006.

	BMI (kg/m^2)		Menopausal status		HRT use
Nutrient	<25	≥25	Pre/peri-menopause	Post-menopause	Never	Ever
Total (Englyst) fiber	1.0 (0.6–1.7)	1.1 (0.7–1.7)	1.2 (0.7–2.1)	1.1 (0.6–1.5)	1.1 (0.6–1.7)	2.5 (0.5–11.3)
Soluble NCP	0.8 (0.4–1.5)	0.7 (0.4–1.2)	0.7 (0.4–1.3)	0.8 (0.5–1.5)	0.8 (0.4–1.2)	4.2 (0.4–17.2)
Total insoluble fiber	1.0 (0.6–1.8)	1.0 (0.5–1.7)	0.9 (0.6–1.3)	1.1 (0.7–1.6)	1.1 (0.6–1.6)	1.8 (0.7–6.5)
Cellulose	1.0 (0.5–1.6)	0.9 (0.5–1.4)	0.8 (0.6–1.2)	1.0 (0.8–1.3)	0.9 (0.5–1.3)	1.0 (0.2–2.7)
Insoluble NCP	0.8 (0.5–1.3)	1.2 (0.6–1.8)	1.0 (0.5–1.7)	0.9 (0.6–1.4)	1.0 (0.5–1.4)	2.5 (0.5–10.6)
Lignin	0.6 (0.3–1.0)	0.6 (0.3–1.1)	0.7 (0.4–1.1)	0.6 (0.4–1.2)	0.6 (0.3–0.9)	2.5 (0.6–8.4)
Vegetable fiber	0.9 (0.3–1.4)	1.0 (0.6–1.5)	0.9 (0.4–1.2)	1.0 (0.5–1.4)	0.9 (0.5–1.3)	2.3 (0.7–7.2)
Fruit fiber	0.8 (0.4–1.3)	0.9 (0.5–1.4)	0.9 (0.3–1.5)	0.8 (0.5–1.3)	0.9 (0.5–1.1)	3.4 (0.6–18.1)
Grain fiber	1.1 (0.7–1.9)	1.2 (0.7–1.8)	1.0 (0.7–1.6)	1.2 (0.5–2.1)	1.0 (0.6–1.5)	0.9 (0.4–2.8)

^aEstimates from conditional logistic regression, conditioned on centre, and age, and adjusted for period of interview, body mass index, physical activity, education, smoking, alcohol consumption, age at menarche, parity, menopausal status, oral contraceptive use, hormone replacement therapy use, diabetes and total energy intake, according to the residual method, when appropriate.

^bORs of highest quintile of intake vs. lowest.