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Table 2 Distribution of demographic characteristics and known breast cancer risk factors for cases and controls included in the study

From: Breast cancer risk assessment with five independent genetic variants and two risk factors in Chinese women

Variables

Testing Set, TS (n= 1,778)

Validation Set, VS (n= 1,881)

TS + VS (n= 3,659)

 

Cases

(n= 878)

Controls

(n= 900)

Cases

(n= 914)

Controls

(n= 967)

Cases

(n= 1,792)

Controls

(n= 1,867)

P-value

Age, yr (Mean ± SD)

51.29 ± 11.38

51.47 ± 11.67

50.11 ± 11.36

48.64 ± 12.28

50.69 ± 11.38

50.01 ± 12.07

0.08

Age group, yr (%)

      

0.06

< 50

425 (48.41)

463 (51.44)

467 (51.09)

526 (54.40)

896 (49.78)

989 (52.97)

 

≥ 50

453 (51.59)

437 (48.56)

447 (48.91)

441 (45.60)

900 (50.22)

878 (47.03)

 

Age at menarche, yr (Mean ± SD)

15.26 ± 1.83

15.85 ± 1.89

15.19 ± 1.94

16.23 ± 1.81

15.22 ± 1.89

16.05 ± 1.86

< 0.001

Age at menarche group, yr (%)

      

< 0.001

< 15 (Early menarche)

331 (38.40)

227 (25.33)

357 (39.98)

169 (17.57)

688 (39.20)

396 (21.31)

 

15 to 17 (Normal menarche)

325 (37.70)

352 (39.29)

333 (37.29)

376 (39.09)

658 (37.49)

728 (39.18)

 

≥ 17 (Late menarche)

206 (23.90)

317 (35.38)

203 (22.73)

417 (43.35)

409 (23.30)

734 (39.50)

 

Age at first live birth, yr (Mean ± SD)

25.62 ± 3.39

24.90 ± 3.35

25.51 ± 3.06

24.17 ± 2.51

25.56 ± 3.22

24.52 ± 2.99

< 0.001d

Age at first live birth group, yr (%) a

      

< 0.001

< 25 (Early birth)

305 (34.74)

398 (44.27)

312 (34.36)

527 (54.67)

617 (34.55)

925 (49.65)

 

≥ 25 a (Late birth)

573 (65.26)

501 (55.73)

596 (65.64)

437 (45.33)

1,169 (65.45)

938 (50.35)

 

Age at menopause, yr. (Mean ± SD) b

49.15 ± 4.09

48.90 ± 4.43

48.71 ± 4.63

49.42 ± 4.04

48.93 ± 4.37

49.16 ± 4.25

0.27

Menopausal status (%) b

      

0.02

Premenopausal

416 (47.38)

437 (48.56)

434 (47.48)

529 (54.71)

850 (47.43)

966 (51.74)

 

Postmenopausal

444 (50.57)

448 (49.78)

463 (50.66)

428 (44.26)

907 (50.61)

876 (46.92)

 

Estrogen receptor (ER) (%) c

       

Positive

369 (42.03)

 

434 (47.48)

 

803 (44.81)

  

Negative

321 (36.56)

 

322 (35.23)

 

643 (35.88)

  

Progesterone receptor (PR) (%) c

       

Positive

396 (45.10)

 

414 (45.30)

 

810 (45.20)

  

Negative

294 (33.49)

 

340 (37.20)

 

634 (35.38)

  
  1. a 10 women (0.27%) without live birth were grouped as "later birth". b Menopause information was available: 907 (51.62%) postmenopausal breast cancer cases and 876 (47.56%) postmenopausal controls. c 1,446 (80.69%) ER status and 1,444 (80.58%) PR status was available in cases. d P-value calculated by t' test for the unequal variances between groups.
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Breast Cancer Research

ISSN: 1465-542X

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