Table 2

Multivariatea comparisons of personal and family health history, socioeconomic, and other characteristics of women with breast cancer and controls in Marin County, California, 1997–99



All women
Women aged 50 years and over
Women under 50 years of age





Variable
(Total N)a
Cases N (%)(285)
Controls N (%)(286)
Multivariate OR (95% CI)
Cases N (%)(201)
Controls N (%)(201)
Multivariate OR (95% CI)
Cases N (%)(84)
Controls N (%)(85)
Multivariate OR (95% CI)

Personal and family health history
First-degree relative with breast cancer
     No
231 (81.1)
230 (80.4)
1.0
162 (80.6)
157 (78.1)
1.0
69 (82.1)
73 (85.9)
1.0
     Yes
54 (18.9)
56 (19.6)
0.95 (0.58–1.5)
39 (19.4)
44 (21.9)
0.84 (0.47–1.5)
15 (17.9)
12 (14.1)
1.3 (0.40–4.0)
Benign biopsy history
     None
196 (68.8)
213 (74.5)
1.0
128 (63.7)
145 (72.1)
1.0
68 (81.0)
68 (80.0)
1.0
     Fine-needle aspiration only
16 (5.6)
19 (6.6)
0.74 (0.34–1.6)
14 (7.0)
10 (5.0)
1.4 (0.48–3.8)
2 (2.4)
9 (10.6)
0.13 (0.02–0.98)
     Surgical biopsyb
73 (25.6)
54 (18.9)
1.1 (0.66–1.7)
59 (29.4)
46 (22.9)
0.97 (0.56–1.7)
14 (16.7)
8 (9.4)
0.78 (0.22–2.9)
Previous radiation treatment
     No
252 (88.4)
266 (93.0)
1.0
174 (86.6)
185 (92.0)
1.0
78 (92.9)
81 (95.3)
1.0
     Yes
33 (11.6)
20 (7.0)
1.7 (0.89–3.3)
27 (13.4)
16 (8.0)
1.6 (0.76–3.5)
6 (7.1)
4 (4.7)
6.1 (1.1–34.9)
Age at menarche
     15 or more years old
18 (6.3)
26 (9.1)
1.0
14 (7.0)
18 (9.0)
1.0
4 (4.8)
8 (9.4)
1.0
     12–14 years old
220 (77.2)
197 (68.9)
1.5 (0.74–3.1)
152 (75.6)
132 (65.7)
1.3 (0.52–3.1)
68 (81.0)
65 (76.5)
2.6 (0.53–12.5)
     11 or less years old
47 (16.5)
63 (22.0)
1.2 (0.51–2.6)
35 (17.4)
51 (25.4)
0.74 (0.27–2.0)
12 (14.3)
12 (14.1)
2.5 (0.37–16.5)
Menopause status
     Premenopausal
81 (28.4)
66 (23.1)
1.0
13 (6.5)
7 (3.5)
1.0
68 (81.0)
59 (69.4)
1.0
     Perimenopausal
29 (10.2)
31 (10.8)
0.52 (0.26–1.0)
19 (9.5)
13 (6.5)
0.76 (0.19–3.0)
10 (11.9)
18 (21.2)
0.17 (0.05–0.59)
     Postmenopausal
175 (61.4)
189 (66.1)
0.40 (0.19–0.84)
169 (84.1)
181 (90.0)
0.45 (0.14–1.5)
6 (7.1)
8 (9.4)
0.38 (0.06–2.3)
Reproductive history
     Never pregnant
45 (15.8)
51 (17.8)
1.0
23 (11.4)
38 (18.9)
1.0
22 (26.2)
13 (15.3)
1.0
     Pregnant, no birth
27 (9.5)
23 (8.0)
1.4 (0.65–3.0)
15 (7.5)
11 (5.5)
2.2 (0.75–6.3)
12 (14.3)
12 (14.1)
0.52 (0.12–2.4)
     Birth, did not breastfeed
57 (20.0)
33 (11.5)
1.9 (0.97–3.9)
53 (26.4)
30 (14.9)
2.6 (1.1–5.8)
4 (4.8)
3 (3.5)
1.9 (0.22–16.0)
     Breastfed
156 (54.7)
179 (62.6)
0.98 (0.58–1.7)
110 (54.7)
122 (60.7)
1.4 (0.68–2.7)
46 (54.8)
57 (67.1)
0.35 (0.11–1.1)
Reproductive history, recategorization of those who had given birth versus never pregnanta
     One birth
53 (18.6)
55 (19.2)
1.0 (0.54–2.0)
36 (17.9)
33 (16.4)
1.4 (0.62–3.4)
17 (20.2)
22 (25.9)
0.36 (0.09–1.4)
     Two births
86 (30.2)
88 (30.8)
1.1 (0.59–1.9)
61 (30.3)
60 (29.9)
1.4 (0.66–3.0)
25 (29.8)
28 (32.9)
0.51 (0.15–1.8)
     Three or more births
74 (26.0)
69 (24.1)
1.3 (0.68–2.4)
66 (32.8)
59 (29.4)
1.9 (0.89–4.1)
8 (9.5)
10 (11.8)
0.18 (0.04–0.90)
Reproductive history, recategorization of those who had breastfed versus never pregnanta
     Breastfed 6 months or less
62 (21.8)
71 (24.8)
0.87 (0.47–1.6)
50 (24.9)
54 (26.9)
1.2 (0.57–2.7)
12 (14.3)
17 (20.0)
0.40 (0.1–1.7)
     Breastfed 7–12 months
41 (14.4)
42 (14.7)
1.3 (0.65–2.6)
26 (12.9)
29 (14.4)
1.6 (0.65–3.8)
15 (17.9)
13 (15.3)
0.54 (0.14–2.1)
     Breastfed more than 12 months
53 (18.6)
66 (23.1)
0.92 (0.49–1.7)
34 (16.9)
39 (19.4)
1.4 (0.61–3.3)
19 (22.6)
27 (31.8)
0.22 (0.06–0.83)
Oral contraceptive use
     Never
68 (23.9)
42 (14.7)
1.0
55 (27.4)
37 (18.4)
1.0
13 (15.5)
5 (5.9)
1.0
     Ever
217 (76.1)
244 (85.3)
0.43 (0.26–0.72)
146 (72.6)
164 (81.6)
0.41 (0.22–0.75)
71 (84.5)
80 (94.1)
0.15 (0.03–0.65)
Hormone replacement therapy (HRT)
     None
129 (45.3)
126 (44.1)
1.0
58 (28.9)
60 (29.9)
1.0
71 (84.5)
66 (77.6)
1.0
     Combination therapy
101 (35.4)
103 (36.0)
0.93 (0.55–1.6)
96 (47.8)
94 (46.8)
0.99 (0.54–1.8)
5 (6.0)
9 (10.6)
0.47 (0.08–2.7)
     Other HRTc
55 (19.3)
57 (19.9)
0.96 (0.55–1.7)
47 (23.4)
47 (23.4)
1.1 (0.54–2.1)
8 (9.5)
10 (11.8)
0.75 (0.17–3.4)
Highest body mass index (BMI) after age 21 daysd
     BMI < 25
184 (64.6)
141 (49.3)
1.0
124 (61.7)
89 (44.3)
1.0
60 (71.4)
52 (61.2)
1.0
     25 ≤ BMI < 30
66 (23.2)
84 (29.4)
0.53 (0.34–0.84)
49 (24.4)
62 (30.8)
0.47 (0.27–0.83)
17 (20.2)
22 (25.9)
0.52 (0.19–1.4)
     BMI ≥ 30
35 (12.3)
61 (21.3)
0.38 (0.22–0.66)
28 (13.9)
50 (24.9)
0.29 (0.15–0.57)
7 (8.3)
11 (12.9)
0.30 (0.08–1.2)
     P for trende


0.0003


0.0008


0.05
Number of mammograms, 1990–94
     Less than four
98 (34.4)
145 (50.7)
1.0
36 (17.9)
73 (36.3)
1.0
62 (73.8)
72 (84.7)
1.0
     Four or more
187 (65.6)
141 (49.3)
2.5 (1.6–4.0)
165 (82.1)
128 (63.7)
2.6 (1.5–4.6)
22 (26.2)
13 (15.3)
2.1 (0.67–6.4)
Socioeconomic status
Socioeconomic status before age 21
     Poor/working class
49 (17.2)
58 (20.3)
1.0
34 (16.9)
51 (25.4)
1.0
15 (17.9)
7 (8.2)
1.0
     Lower middle class
44 (15.4)
31 (10.8)
1.7 (0.86–3.5)
31 (15.4)
26 (12.9)
1.9 (0.84–4.5)
13 (15.5)
5 (5.9)
1.2 (0.16–8.6)
     Middle class
113 (39.6)
132 (46.2)
1.0 (0.58–1.7)
81 (40.3)
85 (42.3)
1.5 (0.80–2.9)
32 (38.1)
47 (55.3)
0.30 (0.07–1.3)
     Upper middle/upper class
79 (27.7)
65 (22.7)
1.3 (0.73–2.4)
55 (27.4)
39 (19.4)
2.2 (1.0–4.6)
24 (28.6)
26 (30.6)
0.23 (0.05–1.1)
Separating upper middle and upper versus poor/working classa
     Upper middle class
68 (23.9)
63 (22.0)
1.1 (0.57–2.0)
46 (22.9)
38 (18.9)
1.6 (0.73–3.4)
22 (26.2)
25 (29.4)
0.22 (0.05–1.1)
     Upper class
11 (3.9)
2 (0.7)
9.7 (1.9–49.0)
9 (4.5)
1 (0.5)
31.5 (3.3–298.6)
2 (2.4)
1 (1.2)
1.6 (0.03–82.1)
Highest degree obtained
     High school (HS)
69 (24.2)
66 (23.1)
1.0
55 (27.4)
55 (27.4)
1.0
14 (16.7)
11 (12.9)
1.0
     Some college or other post-HS
59 (20.7)
66 (23.1)
0.83 (0.47–1.4)
37 (18.4)
47 (23.4)
0.63 (0.32–1.3)
22 (26.2)
19 (22.4)
1.2 (0.32–4.9)
     Bachelor's
105 (36.8)
103 (36.0)
0.99 (0.59–1.7)
71 (35.3)
64 (31.8)
1.1 (0.59–2.1)
34 (40.5)
39 (45.9)
0.73 (0.19–2.8)
     Graduate
52 (18.2)
51 (17.8)
0.93 (0.50–1.7)
38 (18.9)
35 (17.4)
0.89 (0.42–1.9)
14 (16.7)
16 (18.8)
0.80 (0.17–3.8)
Religion in which raised
     Protestant
128 (44.9)
111 (38.8)
1.0
100 (49.8)
84 (41.8)
1.0
28 (33.3)
27 (31.8)
1.0
     Catholic
104 (36.5)
114 (39.9)
0.72 (0.47–1.1)
70 (34.8)
78 (38.8)
0.68 (0.40–1.1)
34 (40.5)
36 (42.4)
0.53 (0.20–1.4)
     Jewish
23 (8.1)
18 (6.3)
1.2 (0.56–2.6)
16 (8.0)
11 (5.5)
1.6 (0.57–4.3)
7 (8.3)
7 (8.2)
0.95 (0.18–4.9)
     Other
18 (6.3)
18 (6.3)
0.94 (0.42–2.1)
7 (3.5)
14 (7.0)
0.33 (0.11–1.0)
11 (13.1)
4 (4.7)
3.2 (0.60–16.7)
     None
12 (4.2)
25 (8.7)
0.39 (0.17–0.91)
8 (4.0)
14 (7.0)
0.53 (0.18–1.6)
4 (4.8)
11 (12.9)
0.20 (0.03–1.1)
Alcohol and tobacco use
Age began drinking alcohol
     Before age 21 years
228 (80.0)
255 (89.2)
1.0
156 (77.6)
176 (87.6)
1.0
72 (85.7)
79 (92.9)
1.0
     After age 21 years
57 (20.0)
31 (10.8)
2.8 (1.6–5.0)
45 (22.4)
25 (12.4)
3.0 (1.5–5.9)
12 (14.3)
6 (7.1)
2.9 (0.60–14.2)
Average drinks after age 21f
     <1 drink per week
81 (28.4)
104 (36.4)
1.0
56 (27.9)
68 (33.8)
1.0
25 (29.8)
36 (42.4)
1.0
     ≥ 1 drinks per week, <2 per day
137 (48.1)
149 (52.1)
1.1 (0.72–1.8)
90 (44.8)
106 (52.7)
0.63 (0.36–1.1)
47 (56.0)
43 (50.6)
3.5 (1.2–10.1)
     ~2 drinks per day
52 (18.2)
27 (9.4)
2.3 (1.2–4.4)
42 (20.9)
22 (10.9)
1.5 (0.70–3.3)
10 (11.9)
5 (5.9)
3.6 (0.79–16.5)f
     ≥ 3 drinks per day
15 (5.3)
6 (2.1)
3.6 (1.2–11.5)
13 (6.5)
5 (2.5)
2.9 (0.80–10.9)
2 (2.4)
1 (1.2)

     P for trende


0.004


0.090


0.030
Lifetime pack-years of cigarette smoking
     None
117 (41.1)
130 (45.5)
1.0
74 (36.8)
87 (43.3)
1.0
43 (51.2)
43 (50.6)
1.0
     Duration ≤ 8.25 years
39 (13.7)
38 (13.3)
1.3 (0.70–2.2)
24 (11.9)
24 (11.9)
1.3 (0.61–2.9)
15 (17.9)
14 (16.5)
2.3 (0.72–7.4)
     > 8.25 years to ≤ 15 years duration
29 (10.2)
42 (14.7)
0.81 (0.44–1.5)
21 (10.4)
28 (13.9)
0.99 (0.45–2.2)
8 (9.5)
14 (16.5)
0.38 (0.11–1.3)
     >15 years to ≤ 28.5 years duration

36 (12.6)
37 (12.9)
1.1 (0.61–2.0)
22 (10.9)
26 (12.9)
1.0 (0.47–2.3)
14 (16.7)
11 (12.9)
1.1 (0.34–3.8)
     Duration > 28.5 years
64 (22.5)
39 (13.6)
2.4 (1.3–4.2)
60 (29.9)
36 (17.9)
3.1 (1.6–5.9)
4 (4.8)
3 (3.5)
2.0 (0.18–21.2)
     P for trende


0.02


0.004


0.78

CI, confidence interval; OR, odds ratio. Statistically significant results are shown in bold. aWomen with complete full interviews were included in the multivariate analyses. ORs adjusted for age and other variables in this table are presented in normal font. Variables in italics are alternative categorizations of selected variables and are adjusted for age and the other variables in the table. bIncludes surgical biopsy alone and surgical biopsy in addition to fine-needle aspiration. cTook either only estrogen (N = 92) or only progesterone (N = 12) compounds, or took them during different times (N = 6), or name of hormone unknown (N = 2). dExcludes weight during pregnancy, nursing, or first 6 months after pregnancy. eP for linear trend in categories given are adjusted for age and other variables in the table. fFor women under age 50, those drinking about two drinks per day and those drinking three or more drinks per day were combined.

Wrensch et al. Breast Cancer Res 2003 5:R88   doi:10.1186/bcr605