Skip to main content

Table 1 Demographics of Study 1 (cancers detected at first screen on entry to the PROCAS study) and Study 2 (cancers detected at a subsequent screen or between screening rounds)

From: Exploring the prediction performance for breast cancer risk based on volumetric mammographic density at different thresholds

 

Study 1

Study 2

Controls

Cases

p value

Controls

Cases

p value

Number (%)

Number (%)

 

Number (%)

Number (%)

 

Age at consent (years)

  

0.9997

  

0.9997

 < 50

53 (6)

19 (6)

 

46 (5)

16 (5)

 

 50–54

242 (26)

79 (25)

 

194 (21)

64 (20)

 

 55–59

153 (16)

52 (16)

 

164 (18)

58 (18)

 

 60–64

229 (24)

77 (24)

 

286 (31)

96 (30)

 

 65–69

196 (21)

66 (21)

 

198 (21)

68 (21)

 

 70+

74 (8)

24 (8)

 

47 (5)

16 (5)

 

HRT use

  

0.0778

  

0.9320

 Unknown

14 (1)

9 (3)

 

23 (2)

6 (2)

 

 Never

568 (60)

208 (66)

 

475 (51)

166 (52)

 

 Previous

315 (33)

83 (26)

 

332 (36)

110 (35)

 

 Current

50 (5)

17 (5)

 

105 (11)

36 (11)

 

BMI (kg/m2)

  

0.9954

  

0.9389

 Unknown

1 (0)

   

1 (0)

 

 < 25

332 (35)

112 (35)

 

335 (36)

117 (37)

 

 25–29

331 (35)

111 (35)

 

341 (36)

113 (36)

 

 ≥ 30

283 (30)

94 (30)

 

259 (28)

87 (27)

 

Menopausal status

  

0.4272

  

0.9889

 Unknown

31 (3)

10 (3)

 

32 (3)

12 (4)

 

 Premenopausal

92 (10)

32 (10)

 

67 (7)

22 (7)

 

 Perimenopausal

112 (12)

38 (12)

 

134 (14)

46 (14)

 

 Postmenopausal

712 (75)

237 (75)

 

702 (75)

238 (75)

 

Ethnic origin

  

0.1880

  

0.2208

 Other/unknown

52 (5)

24 (8)

 

81 (9)

35 (11)

 

 White

895 (95)

293 (92)

 

854 (91)

283 (89)

 

Parity

  

0.7134

  

0.0399

 Unknown

1 (0)

  

1 (0)

4 (1)

 

 Nulliparous

112 (12)

40 (13)

 

91 (10)

44 (14)

 

 Parous

834 (88)

277 (87)

 

843 (90)

270 (85)

 

Tyrer-Cuzick (10 year risk, % (median, Q1–Q3))

2.74 (2.18–3.58)

2.94 (2.29–3.88)

0.0006

2.67 (2.09–3.55)

2.91 (2.24–4.05)

<.0001

Volumetric PD (median, Q1–Q3)

4.90 (3.63–7.19)

5.43 (4.06–8.13)

0.0034

4.79 (3.58–7.01)

5.51 (3.81–7.98)

0.0044

  1. The p values, from likelihood-ratio chi-square tests, indicate whether there are significant difference between cases and controls
  2. HRT hormone replacement therapy, BMI body mass index, Q1 25th percentile, Q3 75th percentile, PD percent density