Table 2

Demographic characteristics and known breast cancer risk factors of study participants*

CategoryCases (n=2575)Controls (n=2809)p Value
Demographic factors
Age (year±SD)50.0±10.852.6±8.2<0.001
Age distribution
 <3067 (2.6)   0<0.001
  30–39351 (13.9)10 (0.4)
  40–49821 (32.4)1101 (39.3)
  50–59804 (31.7)1087 (38.8)
 ≥60490 (19.3)607 (21.6)
Ethnicity
  Chinese1726 (67.0)1686 (60.0)<0.001
  Malay490 (19.0)547 (19.5)
  Indian359 (13.9)576 (20.5)
Family history
Number of first-degree relatives with breast cancer
  02224 (86.4)2454 (87.5)0.061
  1309 (12.0)304 (10.8)
  235 (1.4)45 (1.6)
  37 (0.3)1 (0.04)
Number of second-degree relatives with breast cancer
  02322 (90.2)2640 (94.2)<0.001
  1219 (8.5)148 (5.3)
  230 (1.2)14 (0.5)
  33 (0.1)2 (0.1)
  41 (0.04)   0
  • *Unless otherwise specified, data are presented in no. (%). For each data type, the total number of subjects may differ because of missing or incomplete data.