Table 1.
Characteristics of Control and Case Subjects
| Variables | Controls, n = 3026 | Cases, n = 3026 | P a |
|---|---|---|---|
| Year of birth, mean (range) | 1953.9 (1908–1981) | 1953.7 (1909–1981) | .36 |
| Year of baseline questionnaire, mean (range) | 2002.6 (1992–2009) | 2002.4 (1982–2009) | .01 |
| Year of last contact, mean (range) | 2005.9 (1990–1909) | 2006.0 (1980–1909) | .17 |
| Age of breast cancer diagnosis, mean y (range) | NA | 42.2 (19–80) | NA |
| Year of breast cancer diagnosis, mean (range) | NA | 1995.3 (1940–2009) | NA |
| Mutation, No. (%) | Matched | ||
| BRCA1 | 2255 (74.5%) | 2255 (74.5%) | |
| BRCA2 | 770 (25.5%) | 770 (25.5%) | |
| BRCA1&2 | 1 (0.1%) | 1 (0.1%) | |
| Country of residence, No. (%) | Matched | ||
| USA | 952 (31.5%) | 1221 (31.5%) | |
| Canada | 958 (31.7%) | 890 (31.7%) | |
| Israel | 155 (5.1%) | 155 (5.1%) | |
| Poland | 848 (28.0%) | 848 (28.0%) | |
| Other | 113 (3.7%) | 113 (3.7%) | |
| BMI at age 30 y | 22.4 (13.8– 59.3) | 22.5 (13.3–56.7) | .59 |
| Weight at age 30 y | 132.1 (83.0–425.0) | 131.9 (68.0–373.7) | .81 |
NA indicates not applicable; BMI, body mass index.
Weight and BMI at age 30 years were based on the means for those cases and controls whereby the case was diagnosed with breast cancer at age 30 years or older.
a
The t test to compare means and chi-square test to compare frequencies.