Table 1

Comparison of subjects carrying BRCA mutations

Variable
Control subjects (n = 1,073)
Case subjects (n = 1,073)
Pa

Age (years) at interview, no. (%)



     ≤ 30
17 (1.6)
26 (2.4)

     31–40
219 (20.4)
242 (22.5)

     41–50
415 (38.7)
386 (36.0)

     51–60
277 (25.8)
264 (24.6)

     ≥ 61
145 (13.5)
155 (14.5)
0.32
Age (years) at interview, mean (SD)
47.9 (10.6)
48.6 (10.6)
0.25
Date of birth, mean year
1951.8
1951.2
0.14
Year of interview, mean (range)
1999.7 (1995–2004)
1999.8 (1999–2004)
0.18




Age (years) at diagnosis of breast cancer, no. (%)



     ≤ 30
NA
107 (10.0)

     31–40

478 (44.5)

     41–50

371 (34.5)

     ≥ 51

117 (10.9)

Age (years) at diagnosis of breast cancer, mean (SD)

39.8 (8.3)





Mutation, %



     BRCA1
74.3
74.3

     BRCA2
25.7
25.7





Parity



     No. (%) parous
844 (79.6)
879 (82.8)
0.06
     Parity, mean (SD)
1.9 (1.4)
1.9 (1.3)
0.18




No. (%) who ever used oral contraceptives
662 (62.6)
710 (66.8)
0.04
No. (%) who ever smoked
465 (43.3)
471 (43.9)
0.79




     Country of residence at time of testing, no. (%)



     Canada
420 (39.1)
420 (39.1)

     Israel
20 (1.9)
20 (1.9)

     UK
8 (0.8)
8 (0.8)

     Poland
189 (17.6)
189 (17.6)

     USA
436 (40.6)
436 (40.6)


aAll P values are univariate and were derived using Student's t-test for continuous variables and the χ2 test for categorical variables. NA, not applicable; SD, standard deviation.

Kotsopoulos et al. Breast Cancer Research 2005 7:R833   doi:10.1186/bcr1293