Table 1.
Selected characteristics of contralateral breast cancer cases and control women diagnosed only once with breast cancer
| Characteristic | Controls (n=1506) n % |
Cases (n=482) n % |
|---|---|---|
| Age at first breast cancer diagnosis | ||
| 20–39 | 113 (7.5) | 37 (7.7) |
| 40–49 | 343 (22.8) | 92 (19.1) |
| 50–59 | 455 (30.2) | 135 (28.0) |
| 60–73 | 595 (39.5) | 218 (45.2) |
| Diagnosis year of first tumor | ||
| 1996–1997 | 372 (24.7) | 142 (29.5) |
| 1998–1999 | 437 (29.0) | 136 (28.2) |
| 2000–2001 | 327 (21.7) | 96 (19.9) |
| 2002–2003 | 209 (13.9) | 61 (12.7) |
| 2004–2008 | 161 (10.7) | 47 (9.8) |
| Race | ||
| White | 1383 (92.0) | 445 (92.9) |
| Black | 68 (4.5) | 19 (4.0) |
| Asian | 46 (3.1) | 12 (2.5) |
| Other | 7 (0.5) | 3 (0.6) |
| Missing | 2 | 3 |
| Stage of first tumor | ||
| Local | 946 (65.4) | 333 (70.7) |
| Regional/Distant | 500 (34.6) | 138 (29.3) |
| Missing | 60 | 11 |
| Histology of first tumor | ||
| Ductal | 1087 (80.0) | 339 (77.8) |
| Lobular | 127 (9.4) | 45 (10.3) |
| Mixed ductal/lobular | 130 (9.6) | 49 (11.2) |
| Other | 14 (1.0) | 3 (0.7) |
| Missing | 148 | 46 |
| Surgery | ||
| None | 30 (2.0) | 4 (0.8) |
| Partial mastectomy | 959 (63.7) | 304 (63.1) |
| Total mastectomy | 517 (34.3) | 174 (36.1) |
| Radiation | ||
| No | 431 (28.8) | 143 (29.7) |
| Yes | 1064 (71.2) | 339 (70.3) |
| Missing | 11 | 0 |
| Chemotherapy | ||
| No | 699 (46.7) | 256 (53.1) |
| Yes | 798 (53.3) | 226 (46.9) |
| Missing | 9 | 0 |
| Adjuvant hormonal therapy | ||
| No | 562 (37.6) | 202 (41.9) |
| Yes | 931 (62.4) | 280 (58.1) |
| Missing | 13 | 0 |