Risk and Protective Factors for Breast Cancer in Midwest of Brazil
Table 3
Distribution of socioeconomic and gynecological variables in breast cancer women (cases) and their control subjects, from Midwest of Brazil (2008–2010).
Variable*
Cases ()
Controls ()
Crude OR (95% CI)
value**
%
%
Age (years)
<50
40
43.01
72
38.71
1.00
—
≥50
53
56.99
114
61.29
0.84 (0.50–1.39)
0.490
Education level
Did not study
12
12.90
9
4.84
1.00
—
≤Primary education
59
63.44
133
71.50
0.33 (0.13–0.83)
0.019
≥High school
22
23.66
44
23.66
0.37 (0.14–1.02)
0.056
Per capita income (US$)
>1/2 Brazilian minimum wage
43
46.24
105
60
1.00
—
≤1/2 Brazilian minimum wage
50
53.76
70
40.00
1.74 (1.05–2.89)
0.032
Area of residence
Urban
67
83.75
155
96.27
1.00
—
Rural
13
16.25
6
3.73
5.01 (1.82–13.74)
0.002
Bearing children
Yes
89
95.70
169
90.86
1.00
—
No
4
4.30
17
9.14
0.45 (0.14–1.37)
0.158
Number of children
Nulliparity
4
4.30
17
9.14
1.00
—
1–3 children
62
66.67
108
58.06
2.44 (0.78–7.58)
0.123
>3 children
27
29.03
61
32.80
1.88 (0.58–6.12)
0.294
Total breastfeeding (months)
Never
4
4.30
3
1.64
1.00
—
≤6
12
12.90
21
11.48
0.43 (0.08–2.25)
0.316
7–12
10
10.75
20
10.93
0.37 (0.07–2.01)
0.252
>12
67
72.04
139
75.96
0.36 (0.79–1.66)
0.191
Age at first pregnancy (years)
≤30
83
93.26
155
92.81
1.00
—
>30
6
6.74
12
7.19
0.93 (0.34–2.58)
0.895
Age at menarche (years)
<12 (early)
13
14.94
28
15.30
1.00
—
≥12 (usual)
74
85.06
155
84.70
1.02 (0.50–2.09)
0.939
Age at menopause (years)
<55 (usual)
34
91.89
111
92.50
1.00
—
≥55 (late)
3
8.11
9
7.50
1.09 (.28–4.25)
0.903
Family history of cancer
No
30
32.26
94
50.54
1.00
—
Yes
63
67.74
92
49.46
2.14 (1.27–3.61)
0.004
Family history of breast cancer (mother/sisters)
No
85
91.40
182
97.85
1.00
—
Yes
8
8.60
4
2.15
4.28 (1.25–14.61)
0.020
OR: odds ratio and CI: confidence interval.
*Per capita income: Brazilian minimum wage corresponds to approximately US$ 300; 11 control subjects did not indicate their per capita income; area of residence: information is unavailable for 13 cases and 25 controls; total breastfeeding: 3 controls did not indicate their breastfeeding time; age at first pregnancy: 4 cases and 19 controls did not have children or did not indicate their age at first pregnancy; age at menarche: 6 cases and 3 controls did not indicate their age at menarche; age at menopause: 12 cases and 11 controls did not indicate their age at menopause; 44 cases and 55 controls were premenopausal.
**Wald statistic.
