Variable | CBC cases N = 1521 | UBC controls N = 2212 |
---|---|---|
Age at first diagnosis (years), median (range) | 46 (24-54) | 46 (23-54) |
Age at reference date (years), median (range) | 53 (27-73) | 52 (27-71) |
Length of at-risk period (years)a, median (range) | 6.3 (1.0-19.8) | 5.5 (1.0-19.8) |
Study area, N (%) | ||
Iowab Californiac Seattled Denmarke Canadaf | 201 (13) 658 (43) 224 (15) 279 (18) 159 (10) | 314 (14) 967 (44) 317 (14) 457 (21) 157 (7) |
Year of first breast cancer diagnosis, N (%) | ||
1985–1988 1989–1992 1993–1996 1997–2008 | 238 (16) 415 (27) 427 (28) 441 (29) | 467 (21) 647 (29) 632 (29) 466 (21) |
Age at menarche (years), N (%) | ||
Never had menses <13 ≥13 Unknown | 3 (0) 724 (48) 791 (52) 3 (0) | 6 (0) 965 (44) 1239 (56) 2 (0) |
Number of full-term pregnancies, N (%) | ||
None 1 2 3 ≥4 Unknown | 322 (21) 271 (18) 559 (37) 256 (17) 108 (7) 5 (0) | 412 (19) 341 (15) 842 (38) 387 (17) 225 (10) 5 (0) |
Menopausal statusg, N (%) | ||
Premenopausal Postmenopausal Unknown | 1124 (74) 389 (26) 8 (1) | 1676 (76) 522 (24) 14 (1) |
First-degree family history of breast cancer, N (%) | ||
No Yes Adopted/unknown | 1004 (66) 497 (33) 20 (1) | 1706 (77) 466 (21) 40 (2) |
Stage of first diagnosis, N (%) | ||
Local Regional Unknown | 1061 (70) 448 (29) 12 (1) | 1442 (65) 759 (34) 11 (1) |
Chemotherapy, N (%) | ||
No Yes | 699 (46) 822 (54) | 923 (42) 1289 (58) |
Radiation treatment, N (%) | ||
No Yes Unknown | 641 (42) 880 (58) 0 (0) | 522 (24) 1689 (76) 1 (0) |
BRCA1/2 deleterious mutations, N (%) | ||
No | 596 (39) | 1322 (60) |
Yes | 109 (7) | 76 (3) |
Not testedh | 816 (54) | 814 (37) |
Hormone treatment, N (%) | ||
No Yes Unknown | 964 (63) 557 (37) 0 (0) | 1270 (57) 940 (42) 2 (0) |