Table 2 Risk factors used to generate the Gail model scores among cases of women with invasive breast cancer and non-cases (i.e. women without invasive breast cancer), aged 50 to 69 years within the lifepool cohorta
Gail model variable | Group | Non-cases n = 39,594 (%) | Cases n = 564 (%) | p valueb |
|---|---|---|---|---|
Age at questionnaire (years) | 50–54 | 8820 (22) | 91 (16) | < 0.001 |
55–59 | 11,152 (28) | 153 (27) | ||
60–64 | 10,968 (28) | 158 (28) | ||
65–69 | 8654 (22) | 162 (29) | ||
Age at menarche (years) | ≤ 11 | 6709 (17) | 105 (19) | 0.038 |
12–13 | 19,995 (53) | 300 (55) | ||
≥ 14 | 11,224 (30) | 143 (26) | ||
Missing | 1666 | 16 | ||
Age at first live birthc (years) | < 20 | 3468 (9) | 57 (10) | 0.22 |
20–24 | 12,011 (30) | 156 (28) | ||
25–29 | 12,090 (30) | 175 (31) | ||
≥ 30 | 6413 (16) | 111 (20) | ||
Missing | 2330 | 11 | ||
Nulliparous | 3282 (8) | 54 (10) | ||
Number of first-degree relatives (mother, sisters, daughters) who have had breast cancer | 0 (or not reported) | 30,531 (77) | 390 (69) | < 0.001 |
1 | 8067 (20) | 158 (28) | ||
2 | 933 (2) | 16 (3) | ||
3 | 61 (0) | 0 (0) | ||
4 | 2 (0) | 0 (0) | ||
Breast biopsy | No | 33,048 (86) | 446 (82) | 0.001 |
Yes | 5158 (14) | 100 (18) | ||
Missing | 1388 | 18 | ||
Number of breast biopsies | 0 | 32,824 (87) | 444 (82) | 0.001 |
1 | 3949 (10) | 77 (14) | ||
2 | 1040 (3) | 21 (4) | ||
Missing | 1781 | 22 | ||
Biopsy with atypical hyperplasia | No | 1490 (88) | 23 (92) | 0.76 |
Yes | 209 (12) | 2 (8) | ||
Missingd | 3459 | 75 | ||
Race/ethnicity | Mixede | 38,428 (97) | 555 (98) | 0.059 |
Asian | 1166 (3) | 9 (2) |