Table 3 |
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|
Case-only odds ratios and 95% confidence intervals from logistic regression modelsa of associations between breast cancer tumor subtypes and demographic, reproductive, and lifestyle risk factors, combined LACE and Pathways Studies (n = 2544) |
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|
Luminal A (comparison) |
Luminal Ba |
|||
|
|
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|
n |
N |
OR |
95% CI |
|
|
|
||||
|
Age at diagnosis (years) |
||||
|
≥ 65 (Ref) |
637 |
82 |
Ref |
--- |
|
50 to 64 |
871 |
124 |
1.09 |
0.81, 1.47 |
|
< 50 |
355 |
88 |
1.83 |
1.32, 2.55 |
|
Test for trend |
P = 0.0001 |
|||
|
Race/ethnicity |
||||
|
White (Ref) |
1464 |
215 |
Ref |
--- |
|
African American |
92 |
14 |
0.97 |
0.54, 1.74 |
|
Hispanic |
135 |
28 |
1.32 |
0.85, 2.04 |
|
Asian |
135 |
30 |
1.38 |
0.90, 2.12 |
|
Other |
37 |
7 |
1.29 |
0.56, 2.94 |
|
Menopausal status |
--- |
|||
|
Postmenopausal (Ref) |
1283 |
173 |
Ref |
|
|
Premenopausal |
406 |
95 |
1.32 |
0.87, 2.00 |
|
Family history |
||||
|
No (Ref) |
1453 |
245 |
Ref |
--- |
|
Yes |
410 |
49 |
0.74 |
0.53, 1.02 |
|
Age at first full-term pregnancy (years) |
||||
|
Nulliparous (Ref) |
335 |
51 |
Ref |
--- |
|
< 26 |
959 |
158 |
1.25 |
0.88, 1.78 |
|
≥ 26 |
567 |
85 |
1.04 |
0.72, 1.52 |
|
Parity |
||||
|
Nulliparous (Ref) |
335 |
51 |
Ref |
--- |
|
1 to 2 children |
837 |
150 |
1.24 |
0.88, 1.76 |
|
≥ 3 children |
691 |
93 |
1.03 |
0.70, 1.50 |
|
Lifetime duration of breastfeeding |
||||
|
Never (Ref) |
871 |
135 |
Ref |
--- |
|
0 to 3 months |
255 |
50 |
1.31 |
0.92, 1.88 |
|
≥ 4 months |
711 |
100 |
0.86 |
0.65, 1.14 |
|
Parity among never breastfedb |
||||
|
Nulliparous (Ref) |
321 |
50 |
Ref |
--- |
|
1 to 2 children |
326 |
59 |
1.38 |
(0.89, 2.13) |
|
≥ 3 children |
224 |
26 |
1.01 |
(0.58, 1.76) |
|
Parity among 0 to 3 months breastfedb |
||||
|
1 to 2 children (Ref) |
144 |
33 |
Ref |
--- |
|
≥ 3 children |
108 |
17 |
0.90 |
(0.45, 1.77) |
|
Parity among ≥ 4 months breastfedb |
||||
|
1 to 2 children (Ref) |
358 |
56 |
Ref |
--- |
|
≥ 3 children |
352 |
44 |
0.84 |
(0.54, 1.32) |
|
Alcohol use |
||||
|
Never (Ref) |
709 |
131 |
Ref |
--- |
|
Ever |
880 |
119 |
0.74 |
0.56, 0.98 |
|
Smoking history |
||||
|
Never (Ref) |
921 |
163 |
Ref |
--- |
|
≤ 10 |
251 |
39 |
0.86 |
0.59, 1.27 |
|
11 to 19 |
147 |
22 |
0.93 |
0.57, 1.51 |
|
≥ 20 |
531 |
68 |
0.80 |
0.59, 1.09 |
|
Hormone replacement therapy (postmenopausal only) |
||||
|
Never (Ref) |
314 |
55 |
Ref |
--- |
|
Ever |
943 |
114 |
0.66 |
0.46, 0.94 |
|
Oral contraceptive use |
||||
|
Never (Ref) |
647 |
110 |
Ref |
--- |
|
Ever |
1160 |
172 |
0.73 |
0.55, 0.96 |
|
BMI (kg/m2)c |
||||
|
< 25 (Ref) |
785 |
134 |
Ref |
--- |
|
25 to 29 |
563 |
79 |
0.92 |
0.67, 1.24 |
|
≥ 30 |
500 |
77 |
1.03 |
0.75, 1.41 |
|
BMI (kg/m2) among premenopausalb |
||||
|
< 25 (Ref) |
223 |
50 |
Ref |
--- |
|
25 to 29 |
99 |
21 |
1.11 |
0.62, 2.00 |
|
≥ 30 |
81 |
24 |
1.68 |
0.92, 3.07 |
|
BMI (kg/m2) among postmenopausalb |
||||
|
< 25 (Ref) |
480 |
67 |
Ref |
--- |
|
25 to 29 |
422 |
52 |
0.90 |
0.61, 1.33 |
|
≥ 30 |
372 |
50 |
0.99 |
0.66, 1.47 |
|
|
||||
|
a Adjusted for age at diagnosis, race/ethnicity, and Pathways/LACE study origin except in models with age at diagnosis or race/ethnicity as main predictors. b P for interaction not statistically significant (P > 0.05) in any tumor subtype model. c BMI = body mass index one year pre-diagnosis (LACE) and around diagnosis (Pathways). CI = confidence interval; OR = odds ratio. |
||||
|
Kwan et al. Breast Cancer Research 2009 11:R31 doi:10.1186/bcr2261 |
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