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Table 1 Population characteristics by tumor subtype, basal-like and luminal A breast cancers

From: Association between mammographic density and basal-like and luminal A breast cancer subtypes

Variable

Overall cases versus controls

Cases

Cases

Controls

Basal-like

OR (95% CI)

Luminal A

OR (95% CI)

Subjects, number

491

528

48

 

181

 

Age (CBCS), mean (range), ya

53.2 (28 to 74)

54.0 (31 to 74)

50.2 (33 to 73)

0.99 (0.96, 1.02)

54.5 (31, 74)

1.04 (1.02, 1.06)

BMI, mean (95% CI)

28.6 (15.1, 60.6)

28.8 (14.6, 60.9)

30.9 (19.1 to 44.2)

1.06 (1.02, 1.10)

28.5 (15.0, 52.6)

1.00 (0.98, 1.03)

Number of days, mean (95% CI)b

−21 (−1401, 365)

149 (−1617, 1095)

−27 (−938, 365)

−10 (−1050, 365)

Race, n (%)

      

 White

297 (60.5%)

324 (61.4%)

21 (43.8%)

1.00

116 (64.1%)

1.00

 African American

194 (39.5%)

204 (38.6%)

27 (56.3%)

3.32 (1.80, 6.12)

65 (35.9%)

1.31 (0.90, 1.89)

Menopausal status, n (%)

      

 Premenopausal

200 (40.7%)

213 (40.3%)

25 (52.1%)

1.00

67 (37.0%)

1.00

 Postmenopausal

291 (59.3%)

315 (59.7%)

23 (47.9%)

0.90 (0.49, 1.65)

114 (63.0%)

1.83 (1.27, 2.65)

Family history, n (%)c

      

 No

386 (81.1%)

440 (85.6%)

39 (83.0%)

1.00

149 (84.2%)

1.00

 Yes

90 (18.9%)

74 (14.4%)

8 (17.0%)

1.24 (0.55-2.82)

28 (15.8%)

1.11 (0.67-1.84)

 Missing

15

14

1

 

4

 

Age at menarche, n (%)

      

 <13 y

257 (52.3%)

230 (43.6%)

32 (66.7%)

1.00

92 (50.8%)

1.00

 ≥13 y

234 (47.7%)

298 (56.4%)

16 (33.3%)

0.37 (0.19-0.70)

89 (49.2%)

0.76 (0.53-1.09)

Parity and age at FFTP

      

 Nulliparous

74 (15.1%)

67 (12.7%)

6 (12.5%)

1.00

31 (17.1%)

1.00

 Parous, <26 y

312 (63.5%)

347 (65.7%)

36 (75.0%)

2.07 (1.04-4.15)

107 (59.1%)

0.93 (0.64-1.34)

 Parous, 26+y

105 (21.4%)

114 (21.6%)

6 (12.5%)

0.43 (0.18-1.06)

43 (23.8%)

0.96 (0.63-1.47)

Breastfeeding, n (%)

      

 Never

299 (60.9%)

324 (61.4%)

32 (66.7%)

1.00

110 (60.8%)

1.00

 Ever

192 (39.1%)

204 (38.6%)

16 (33.3%)

0.84 (0.44-1.60)

71 (39.2%)

1.09 (0.75-1.57)

Lifetime duration lactation, n (%)

      

 Never

299 (60.9%)

324 (61.4%)

32 (66.7%)

1.00

110 (60.8%)

1.00

 >0-3 months

72 (14.7%)

69 (13.1%)

9 (18.8%)

1.71 (0.77-3.79)

26 (14.4%)

1.14 (0.68-1.92)

 4+ months

120 (24.4%)

135 (25.6%)

7 (14.6%)

0.50 (0.22-1.16)

45 (24.9%)

1.02 (0.67-1.55)

Current HT use, n (%)d

      

 Yes

129 (26.4%)

181 (35.0%)

9 (18.8%)

1.00

43 (23.9%)

1.00

 No

359 (73.6%)

336 (65.0%)

39 (81.2%)

2.36 (1.11-5.05)

137 (76.1%)

1.84 (1.23-2.77)

 Missing

3

11

0

 

1

 

Oral contraceptive use, n (%)

      

 Never

170 (34.6%)

170 (32.4%)

11 (22.9%)

1.00

72 (39.8%)

1.00

 Ever

321 (65.4%)

355 (67.6%)

37 (77.1%)

1.21 (0.59-2.46)

109 (60.2%)

0.49 (0.34-0.71)

 Missing

0

3

0

 

0

 

WHR, n (%)

      

 <0.77

132 (27.3%)

169 (32.3%)

4 (8.7%)

1.00

45 (25.4%)

1.00

 0.77 to 0.83

171 (35.3%)

173 (33.0%)

17 (37.0%)

1.19 (0.63-2.24)

69 (39.0%)

1.41 (0.97-2.05)

 ≥0.84

181 (37.4%)

182 (34.7%)

25 (54.3%)

2.40 (1.30-4.42)

63 (35.6%)

1.17 (0.80-1.71)

 Missing

7

4

2

 

4

 
  1. aMean age at diagnosis for cases and selection for controls in the CBCS; bmean number of days between diagnosis date for cases and selection date for controls in the CBCS, and the date of the mammogram chosen to assess mammographic density; cfirst-degree family history of breast cancer; dcurrent hormone therapy use at the time of the mammogram. OR, odds ratio; CBCS, Carolina Breast Cancer Study; BMI, body mass index; FFTP, first full-term pregnancy; HT, hormone therapy; WHR, waist-to-hip ratio; n, number of subjects.
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Breast Cancer Research

ISSN: 1465-542X

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