Supplemental Table S2. Association of non-dense area with breast cancer, by the level of breast cancer risk factor a.
st
Breast cancer risk factor
Alcohol consumption, g/day
0
>0-<5
≥5
History of benign breast
disease
No
Yes
Family history of breast cancer
No
Yes
Postmenopausal hormone use
(PMH)
None
Past
Current
Age at menarche, yrs
<12
12-13
>13
Nulliparityc
Nulliparous
Parous
Parityd
1
2
≥3
Age at 1stchild’s birth, yrse
≤25
>25
1 quartile
(reference)
N
OR
Cases/
Controls
nd
2 quartile
N
Cases/
Controls
OR
(95% CI)
Non-dense area b
3rd quartile
N
Cases/
Controls
OR
(95% CI)
4th quartile
N
Cases/
Controls
OR
(95% CI)
p for
trend
P for
interaction
104/149
115/132
121/154
1.00
1.00
1.00
87/158
69/142
75/134
0.69 (0.47-1.01)
0.52 (0.35-0.79)
0.74 (0.49-1.10)
97/153
48/151
68/126
0.77 (0.52-1.14)
0.32 (0.20-0.50)
0.67 (0.43-1.03)
104/180
59/158
56/93
0.60 (0.38- 0.92)
0.35 (0.21-0.56)
0.75 (0.45-1.23)
0.05
<0.0001
0.25
0.66
212/326
140/120
1.00
1.00
164/339
79/113
0.65 (0.50- 0.85)
0.61 (0.41-0.91)
160/325
66/121
0.60 (0.45- 0.80)
0.47 (0.31- 0.72)
159/339
64/108
0.50 (0.36- 0.69)
0.53 (0.33- 0.84)
<0.001
0.01
0.14
286/382
66/64
1.00
1.00
197/388
46/64
0.63 (0.50-0.80)
0.69 (0.39-1.21)
181/379
45/67
0.56 (0.43-0.73)
0.55 (0.30-1.00)
176/383
47/64
0.51 (0.38- 0.68)
0.50 ( 0.26-0.96)
<0.0001
0.04
0.64
49/102
57/95
236/235
1.00
1.00
1.00
53/122
45/100
137/215
0.82 (0.49-1.36)
0.66 (0.40-1.10)
0.58 (0.43- 0.78)
43/126
53/117
119/189
0.55 (0.32-0.96)
0.64 ( 0.38-1.08)
0.55 (0.40- 0.75)
67/131
45/112
100/191
0.72 (0.41-1.29)
0.50 (0.28- 0.92)
0.42 (0.30-0.61)
0.33
0.04
<0.0001
0.04
73/78
202/254
77/114
1.00
1.00
1.00
56/90
141/256
46/106
0.58 (0.36-0.96)
0.68 (0.51-0.91)
0.60 (0.37- 0.97)
52/107
128/258
46/81
0.42 (0.25-0.71)
0.57 (0.41-0.78)
0.78 (0.47-1.31)
60/120
130/249
33/78
0.42 (0.24- 0.74)
0.56 (0.39-0.79)
0.52 (0.29-0.95)
<0.01
<0.01
0.07
0.46
31/33
321/413
1.00
1.00
15/27
228/425
0.60 (0.24-1.52)
0.63 (0.50-0.80)
16/21
210/425
0.80 (0.27-2.35)
0.54 (0.43-0.69)
21/22
202/425
1.49 (0.51-4.37)
0.47 (0.36-0.62)
0.27
<0.0001
30/31
95/119
192/262
1.00
1.00
1.00
14/17
53/98
157/306
0.52 (0.18-1.50)
0.63 (0.40-0.99)
0.63 (0.48-0.84)
15/18
53/105
140/298
0.54 (1.20-1.49)
0.59 (0.37-0.95)
0.53 (0.39-0.72)
12/30
44/102
139/291
0.17 (0.05-0.63)
0.47 (0.27-0.80)
0.49 (0.35-0.68)
0.01
0.01
<0.001
158/191
159/221
1.00
1.00
109/234
115/187
0.49 (0.35-0.69)
0.82 (0.59-1.14)
101/219
107/202
0.45 (0.32-0.65)
0.66 (0.47-0.93)
94/223
101/200
0.38 (0.25-0.56)
0.57 (0.38-0.84)
<0.0001
<0.01
0.03
0.17
0.31
Breast cancer risk factor
Body Mass Index, kg/m2
<25
25-<30
≥30
Physical activity (mets/week)
<4.4
4.4-<12
12-<25.5
≥ 25.5
Age at menopause, yrs
<50
50-<55
≥55
a
1st quartile
(reference)
N
OR
Cases/
Controls
2nd quartile
N
Cases/
Controls
OR
(95% CI)
Non-dense area b
3rd quartile
N
Cases/
Controls
OR
(95% CI)
4th quartile
N
Cases/
Controls
OR
(95% CI)
p for
trend
P for
interaction
0.07
252/343
89/88
11/15
1.00
1.00
1.00
110/210
98/186
35/56
0.71 (0.53-0.95)
0.50 (0.34-0.75)
0.83 (0.33-2.10)
78/163
86/176
62/107
0.65 (0.46-0.90)
0.44 (0.29-0.67)
0.76 (0.31-1.82)
36/114
89/144
98/189
0.42 (0.27-0.66)
0.54 (0.35-0.84)
0.65 (0.27-1.56)
<0.0001
0.05
0.22
79/99
92/100
93/122
88/125
1.00
1.00
1.00
1.00
59/107
79/113
46/113
59/119
0.55 (0.34-0.90)
0.76 (0.49-1.18)
0.45 (0.28-0.71)
0.70 (0.45-1.09)
59/121
59/89
58/115
50/121
0.52 (0.31-0.85)
0.65 (0.40-1.06)
0.49 (0.30-0.78)
0.54 (0.33-0.87)
72/143
48/118
49/99
54/87
0.46 (0.27-0.80)
0.37 (0.22- 0.65)
0.48 (0.28-0.80)
0.78 (0.45-1.35)
0.02
<0.001
0.02
0.34
111/137
207/264
20/24
1.00
1.00
1.00
78/146
146/279
16/25
0.63 (0.43-0.94)
0.62 (0.46-0.82)
0.70 (0.27-1.85)
66/131
141/282
17/30
0.56 (0.37-0.87)
0.54 (0.40-0.73)
0.80 (0.30-2.17)
73/147
135/269
15/30
0.52 (0.33-0.82)
0.49 (0.35-0.70)
0.63 (0.22-1.82)
0.01
<0.001
0.45
Multivariate models in stratified analyses are adjusted for the following covariates (with the exception of the covariate used for stratification) : age at diagnosis
(continuous, years), body mass index (continuous, kg/m2), age at menarche (<12, 12-13, or >13 years), parity and age at first birth (i.e., age at the end of the first
pregnancy lasting ≥6 months, modeled as nulliparous, any number of children with age at birth<25 years, any number of children with age at birth ≥25 years),
menopausal hormone therapy (never used hormones, current hormone use, past hormone use), age at menopause (50, 50–<55, ≥55 years), a family history of
breast cancer (yes or no), a biopsy-confirmed history of benign breast disease (yes vs. no), alcohol consumption (0, <5, or ≥5 g/day), and smoking status (ever vs.
never)
b
Non-dense area quartiles are defined as follows: 1st: <80 cm2; 2nd: 80-<133 cm2; 3rd: 133-<203 cm2; 4th: ≥203 cm2
c
Multivariate models in stratified analyses are adjusted for the following covariates: age at diagnosis (continuous, years), body mass index (continuous, kg/m2),
age at menarche (<12, 12-13, or >13 years), age at first birth (among parous only, continuous), menopausal hormone therapy (never used hormones, current
hormone use, past hormone use), age at menopause (50, 50–<55, ≥55 years), a family history of breast cancer (yes or no), a biopsy-confirmed history of benign
breast disease (yes vs. no), alcohol consumption (0, <5, or ≥5 g/day), and smoking status (ever vs. never)
d
Among parous women only; multivariate models in stratified analyses are adjusted for age at diagnosis (continuous, years), body mass index (continuous,
kg/m2), age at menarche (<12, 12-13, or >13 years), age at first birth (continuous), menopausal hormone therapy (never used hormones, current hormone use,
past hormone use), age at menopause (50, 50–<55, ≥55 years), a family history of breast cancer (yes or no), a biopsy-confirmed history of benign breast disease
(yes vs. no), alcohol consumption (0, <5, or ≥5 g/day), and smoking status (ever vs. never)
e
Among parous women only; multivariate models in stratified analyses are adjusted for age at diagnosis (continuous, years), body mass index (continuous,
kg/m2), age at menarche (<12, 12-13, or >13 years), parity (continuous), menopausal hormone therapy (never used hormones, current hormone use, past hormone
use), age at menopause (50, 50–<55, ≥55 years), a family history of breast cancer (yes or no), a biopsy-confirmed history of benign breast disease (yes vs. no),
alcohol consumption (0, <5, or ≥5 g/day), and smoking status (ever vs. never)
0.08
0.69