Table 3 Cox’s proportional hazard regression model for overall survival (OS) and breast cancer specific survival (BCSS) among breast cancer subtypes

ER and/or PR + and HER 2 -

 No. of participants

19674

1420

20248

846

 Underweight BMI

659(3.35)

47(3.31)

1.17(0.87-1.57)

0.2902

1.26(0.94-1.69)

0.1269

678(3.35)

28(3.31)

1.17(0.80-1.71)

0.4239

1.24(0.85-1.82)

0.2684

 Normal BMI

13352(67.87)

827(58.24)

1.00

1.00

13686(67.59)

493(58.27)

1.00

1.00

 Overweight BMI

4901(24.91)

462(32.54)

1.48(1.32-1.66)

<0.0001

1.32(1.18-1.48)

<0.0001

5084(25.11)

279(32.98)

1.49(1.29-1.73)

0.0035

1.30(0.96-1.76)

0.0874

 Obese BMI

762(3.87)

84(5.92)

1.74(1.39-2.18)

<0.0001

1.48(1.18-1.85)

0.0006

800(3.95)

46(5.44)

1.57(1.16-2.12)

<0.0001

1.31(1.13-1.52)

0.0003

ER and/or PR + and HER 2 +

 No. of participants

3691

427

3851

267

 Underweight BMI

130(3.52)

14(3.28)

0.95(0.56-1.62)

0.8463

1.07(0.63-1.83)

0.802

139(3.61)

5(1.87)

0.54(0.22-1.31)

0.1737

0.61(0.25-1.48)

0.2705

 Normal BMI

2612(70.77)

297(69.56)

1.00

1.00

2726(70.79)

183(68.54)

1.00

1.00

 Overweight BMI

827(22.41)

102(23.89)

1.06(0.85-1.33)

0.5960

1.02(0.81-1.28)

0.875

856(22.23)

73(27.34)

1.24(0.95-1.63)

0.1177

1.18(0.90-1.55)

0.2251

 Obese BMI

122(3.31)

14(3.28)

1.05(0.61-1.79)

0.8608

0.94(0.55-1.61)

0.8193

130(3.38)

6(2.25)

0.72(0.32-1.62)

0.4277

0.62(0.27-1.39)

0.2449

ER and PR - and HER 2 +

 No. of participants

3349

538

3551

336

 Underweight BMI

94(2.81)

27(5.02)

1.79(1.21-2.65)

0.0034

1.67(1.12-2.47)

0.0113

103(2.90)

18(5.36)

1.88(1.16-3.05)

0.0099

1.79(1.11-2.90)

0.0179

 Normal BMI

2288(68.32)

344(63.94)

1.00

1.00

2418(68.09)

214(63.69)

1.00

1.00

 Overweight BMI

847(25.29)

141(26.21)

1.09(0.90-1.33)

0.3926

0.94(0.77-1.14)

0.5093

900(25.34)

88(26.19)

1.09(0.85-1.40)

0.4921

0.93(0.73-1.19)

0.5715

 Obese BMI

120(3.58)

26(4.83)

1.38(0.93-2.06)

0.1132

1.18(0.79-1.76)

0.4247

130(3.66)

16(4.76)

1.35(0.81-2.24)

0.2496

1.16(0.70-1.93)

0.5683

ER and PR - and HER 2 -

 No. of participants

6424

1012

6770

666

 Underweight BMI

215(3.35)

34(3.36)

1.09(0.77-1.54)

0.6222

1.19(0.84-1.68)

0.3333

225(3.32)

24(3.60)

1.14(0.76-1.72)

0.5347

1.27(0.84-1.92)

0.2606

 Normal BMI

4206(65.47)

610(60.28)

1.00

1.00

4402(65.02)

414(62.16)

1.00

1.00

 Overweight BMI

1727(26.88)

311(30.73)

1.20(1.05-1.38)

0.0080

1.07(0.93-1.23)

0.3301

1849(27.31)

189(28.38)

1.07(0.90-1.27)

0.4398

0.93(0.79-1.11)

0.4320

 Obese BMI

276(4.30)

57(5.63)

1.37(1.04-1.80)

0.0234

1.18(0.90-1.55)

0.2395

294(4.34)

39(5.86)

1.38(0.99-1.91)

0.0571

1.16(0.84-1.61)

0.3749

Unknown

 No. of participants

3415

1071

3777

709

 Underweight BMI

131(3.84)

36(3.36)

0.98(0.70-1.37)

0.8923

1.11(0.79-1.55)

0.5528

139(3.68)

28(3.95)

1.16(0.79-1.70)

0.44

1.29(0.87-1.89)

0.2010

 Normal BMI

2308(67.58)

675(63.03)

1.00

1.00

2542(67.30)

441(62.20)

1.00

1.00

 Overweight BMI

862(25.24)

303(28.29)

1.18(1.03-1.35)

0.0153

1.12(0.98-1.28)

0.1042

962(25.47)

203(28.63)

1.20(1.02-1.42)

0.0283

1.15(0.97-1.36)

0.1030

 Obese BMI

114(3.34)

57(5.32)

1.61(1.23-2.11)

0.0005

1.36(1.04-1.79)

0.0261

134(3.55)

37(5.22)

1.56(1.11-2.18)

0.0099

1.36(0.97-1.90)

0.0747