Skip to main content

Table 2 Association of mammographic density with carrier status and other characteristics in healthy female mutation carriers (controls) from BRCA1/BRCA2 families

From: Mammographic density and breast cancer in women from high risk families

   Categories of mammographic density    
Variable Number <=10 % 11−25 % 26−50 % 51−75 % >75 % Odds ratioa 95 % CIa P value
Carrier status         
 Non-carrier 219 21 % 20 % 33 % 17 % 9 % 1.00   
BRCA1 or BRCA2 443 24 % 20 % 34 % 16 % 6 % 0.75 0.54, 1.04 0.085
BRCA1 227 22 % 25 % 29 % 19 % 6 % 0.84 0.58, 1.23 0.376
BRCA2 216 26 % 15 % 39 % 14 % 6 % 0.67 0.47, 0.96 0.028
Age at mammography, years         
 <35 188 10 % 14 % 36 % 27 % 13 % 1.00   
 35−44 199 17 % 19 % 39 % 17 % 8 % 0.94 0.54, 1.62 0.826
 45−54 170 29 % 25 % 31 % 12 % 3 % 0.79 0.33, 1.90 0.603
 >=55 105 49 % 25 % 24 % 3 % 0 % 0.57 0.15, 2.20 0.415
 Linear trend (per year)        0.97 0.95, 0.99 <0.001
Body mass index          
 <25 396 10 % 17 % 39 % 24 % 10 % 1.00   
 25.0−29.9 166 36 % 26 % 28 % 7 % 3 % 0.28 0.19, 0.40 <0.001
 >=30 100 51 % 24 % 23 % 2 % 0 % 0.16 0.10, 0.25 <0.001
 Linear trend (per unit)        0.83 0.80, 0.86 <0.001
Menopausal status & type of menopause        
 Premenopausal 457 15 % 17 % 37 % 21 % 9 % 1.00   
 Natural menopause 142 41 % 24 % 28 % 6 % 1 % 0.72 0.45, 1.16 0.179
 Surgical menopause 63 38 % 35 % 21 % 6 % 0 % 0.56 0.33, 0.96 0.034
Nulliparous          
 No 460 29 % 23 % 33 % 13 % 2 % 1.00   
 Yes 202 9 % 14 % 35 % 24 % 17 % 1.87 1.28, 2.73 0.001
Age at first birth, years (only parous women)        
 >30 131 25 % 17 % 35 % 17 % 6 % 1.00   
 25−29 170 25 % 25 % 34 % 15 % 1 % 1.17 0.72, 1.88 0.526
 20−24 151 35 % 24 % 30 % 9 % 2 % 1.10 0.67, 1.82 0.706
 <20 26 38 % 23 % 27 % 12 % 0 % 0.72 0.31, 1.66 0.436
 Linear trend (per year)        1.00 0.97, 1.05 0.745
Hormonal replacement therapy        
 No 636 23 % 20 % 34 % 17 % 7 % 1.00   
 Yes 26 23 % 27 % 27 % 15 % 8 % 1.71 0.87, 3.38 0.120
Hormonal preventive therapy         
 No 656 23 % 20 % 34 % 17 % 7 % 1.00   
 Yes 6 33 % 17 % 50 % 0 % 0 % 0.67 0.25, 1.82 0.434
Oral contraception          
 No 214 22 % 18 % 34 % 19 % 7 % 1.00   
 Yes 369 22 % 21 % 33 % 17 % 7 % 0.93 0.67, 1.27 0.637
Type of image          
 Analog 194 26 % 21 % 34 % 13 % 6 % 1.00   
 Digital 468 22 % 20 % 34 % 18 % 7 % 1.09 0.79, 1.50 0.588
Number of projections          
 One or two 53 15 % 17 % 40 % 21 % 8 % 1.00   
 Three or Four 609 24 % 20 % 33 % 16 % 7 % 1.17 0.70, 1.94 0.544
  1. aAdjusted for age at mammogram, body mass index, menopause (premenopausal, natural menopause, surgical menopause), type of mammogram, parity (nulliparous versus parous ), carrier status (non-carrier, BRCA1, BRCA2) and subsequent development of breast cancer (no, yes)