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Table 6 Oral contraceptive use in relation to breast cancer risk, stratified by body mass index a

From: A case–control analysis of oral contraceptive use and breast cancer subtypes in the African American Breast Cancer Epidemiology and Risk Consortium

 

BMI <25.0 kg/m 2

BMI 25.0 to 29.9 kg/m 2

BMI ≥30.0 kg/m 2

 

Controls ( n )

Cases ( n )

OR

(95% CI)

Controls ( n )

Cases ( n )

OR

(95% CI)

Controls ( n )

Cases ( n )

OR

(95% CI)

Never users

931

231

1.00

Reference

1,503

387

1.00

Reference

2,096

637

1.00

Reference

Ever users

1,371

350

1.09

(0.88 to 1.35)

1,746

521

1.13

(0.95 to 1.35)

2,211

707

1.26

(1.09 to 1.45)

OC recency

            

  < 5 years ago

361

87

1.22

(0.87 to 1.71)

320

111

1.58

(1.16 to 2.14)

377

112

1.57

(1.19 to 2.08)

 5 to 9 years ago

156

32

0.87

(0.55 to 1.38)

175

46

1.06

(0.71 to 1.58)

204

69

1.71

(1.23 to 2.37)

  ≥ 10 years ago

851

230

1.09

(0.87 to 1.38)

1,248

363

1.09

(0.90 to 1.31)

1,627

518

1.17

(1.01 to 1.36)

  P trend

  

0.17

  

0.05

  

0.04

OC duration

            

  < 5 years

566

135

1.05

(0.80 to 1.37)

726

198

1.12

(0.90 to 1.39)

986

278

1.09

(0.91 to 1.30)

 5 to 9 years

408

109

1.11

(0.83 to 1.49)

544

152

1.04

(0.82 to 1.33)

651

213

1.34

(1.09 to 1.64)

  ≥ 10 years

397

105

1.11

(0.83 to 1.50)

476

171

1.27

(1.00 to 1.61)

571

212

1.48

(1.20 to 1.82)

  P trend

  

0.67

  

0.48

  

<0.01

  1. BMI, body mass index; CI, confidence interval; OC, oral contraceptive; OR, odds ratio. aORs adjusted for age, study, time period, geographic region, education, age at menarche, parity, age at first birth, lactation, first-degree family history of breast cancer, menopausal status and age at menopause, duration of female hormone use, body mass index, alcohol consumption, and pack-years of cigarette smoking. P trend does not include never users.
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Breast Cancer Research

ISSN: 1465-542X

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