Table 4

Proportional hazards regression model: hazard ratio and 95% confidence interval (CI) for mastectomy-treated breast cancer patients in the Surveillance, Epidemiology, and End Results (SEER) Breast Implant Surveillance Study, 1983–1989 (n = 4385)a

Covariate

Distribution of sample

Breast cancer mortality

Non-breast cancer mortality


n

%

Hazard ratio

95% confidence interval

Hazard ratio

95% confidence interval


Implant status

No (referent)

3568

81.4

1.00

-

1.00

-

Yes

817

18.6

0.54

0.43–0.67

0.59

0.41–0.85

Age at diagnosis

< 35 years

163

3.7

1.95

1.42–2.69

0.24

0.09–0.66

35–44 years

805

18.4

1.29

1.07–1.56

0.19

0.12–0.30

45–54 years

1332

30.4

1.02

0.86–1.20

0.35

0.26–0.46

55–64 years (referent)

2085

47.6

1.00

-

-

-

Race/ethnicity

Non-Hispanic White (referent)

3915

89.3

1.00

-

1.00

-

Non-Hispanic Black

131

3.0

0.90

0.58–1.39

1.58

0.93–2.68

Hispanic

120

2.7

1.37

0.93–2.04

1.22

0.64–2.33

Non-Hispanic Asian

160

3.7

0.86

0.57–1.31

0.68

0.33–1.39

Other/unknown

59

1.4

0.75

0.37–1.50

1.36

0.60–3.07

Stage at diagnosis

Local (referent)

3126

71.3

1.00

-

1.00

-

Regional

1208

27.6

2.28

1.97–2.63

1.86

1.65–2.09

Unstaged

51

1.2

3.80

2.41–5.99

3.35

2.28–4.92

SEER region

San Francisco–Oakland (referent)

1624

37.0

1.00

-

1.00

-

Seattle–Puget Sound

1423

34.1

1.10

0.91–1.32

1.17

0.91–1.51

Iowa

1268

28.9

1.15

0.96–1.38

0.86

0.66–1.13

Year of diagnosis

1983 (referent)

1037

23.7

1.00

-

1.00

-

1985

1003

22.9

1.06

0.88–1.29

0.96

0.73–1.27

1987

1232

28.1

0.97

0.80–1.18

1.05

0.78–1.40

1989

1113

25.4

0.84

0.68–1.04

1.12

0.80–1.56

Grade

Well differentiated (referent)

142

3.2

1.00

-

1.00

-

Moderately differentiated

695

15.9

2.16

1.13–4.13

0.75

0.42–1.34

Poorly differentiated

817

18.6

3.45

1.82–6.53

0.79

0.44–1.40

Undifferentiated

182

4.2

4.97

2.52–9.78

1.23

0.60–2.52

Unknown

2549

58.1

2.41

1.28–4.52

0.85

0.50–1.45

Histology

Ductal (referent)

3253

74.2

1.00

-

1.00

-

Lobular

279

6.4

1.09

0.82–1.44

1.26

0.88–1.81

Mixed ductal and lobular

167

3.8

1.06

0.74–1.53

0.66

0.32–1.33

Other

686

15.6

0.71

0.57–0.89

1.01

0.76–1.34

Radiation therapy

No (referent)

4047

92.3

1.00

-

1.00

-

Yes

329

7.5

1.43

1.15–1.78

0.84

0.54–1.30

Unknown

9

0.2

4.68

1.74–12.60

-

-

Type of breast implantb

Silicone gel (referent)

274

39.8

1.00

-

1.00

-

Saline

118

17.1

1.01

0.44–2.34

1.75

0.29–10.39

Double lumen

240

34.8

1.49

0.83–2.70

3.13

0.91–10.78

Other

26

3.8

1.11

0.24–5.03

-

-

Unknown

31

4.5

2.03

0.71–5.79

6.59

1.17–37.06


aAdjusted for age, year, stage at diagnosis, race/ethnicity, SEER region, tumor grade, histology, and radiation therapy.

bModel (n = 689) restricted to women with implant-specific information and concordant bilateral implants

Le et al. Breast Cancer Res 2005 7:R184-R193   doi:10.1186/bcr974

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