Table 1 Selected patient and clinical characteristics among 16,004 women diagnosed with a first primary unilateral invasive breast cancer at three Kaiser Permanente sites, 1990–2016 and followed through 2017
From: Risk of second primary cancer among women in the Kaiser Permanente Breast Cancer Survivors Cohort
| Â | Â | Second cancer case status | ||
|---|---|---|---|---|
Characteristics of the first breast cancer | Total (N = 16,004) | Second cancer cases (n = 1,562) | Second non-breast cancer cases (n = 1,112) | Non-cases (n = 14,298)a |
n (%) | n (%) | n (%) | n (%) | |
Year of diagnosis, mean (SD) | 2003.0 (6.9) | 1999.3 (5.9) | 1999.5 (6.0) | 2003.4 (6.8) |
Year of diagnosisb | – |  |  |  |
 1990–1994 | 2035 (12.7) | 380 (24.3) | 268 (24.1) | 1623 (11.4) |
 1995–1999 | 3426 (21.4) | 466 (29.8) | 314 (28.2) | 2899 (20.3) |
 2000–2004 | 3696 (23.1) | 394 (25.2) | 281 (25.3) | 3267 (22.9) |
 2005–2009 | 3541 (22.1) | 235 (15.0) | 182 (16.4) | 3293 (23.0) |
 2010–2016 | 3306 (20.7) | 87 (5.6) | 67 (6.0) | 3216 (22.5) |
Age at diagnosis, years, mean (SD) | 60.7 (12.0) | 63.4 (11.2) | 64.6 (10.8) | 60.5 (12.0) |
Age at diagnosis, years | ||||
 20–39 | 630 (3.9) | 41 (2.6) | 18 (1.6) | 579 (4.1) |
 40–49 | 2635 (16.5) | 174 (11.1) | 103 (9.3) | 2424 (17.0) |
 50–59 | 4325 (27.0) | 341 (21.8) | 229 (20.6) | 3944 (27.6) |
 60–69 | 4452 (27.8) | 523 (33.5) | 375 (33.7) | 3895 (27.2) |
 70–79 | 3117 (19.5) | 394 (25.2) | 315 (28.3) | 2705 (18.9) |
 80–84 | 845 (5.3) | 89 (5.7) | 72 (6.5) | 751 (5.3) |
Race | ||||
 White | 14,691 (91.8) | 1468 (94.0) | 1055 (94.9) | 13,091 (91.6) |
 Black | 458 (2.9) | 38 (2.4) | 21 (1.9) | 416 (2.9) |
 American Indian/Alaskan Native | 91 (0.6) | 6 (0.4) | 5 (0.5) | 82 (0.6) |
 Asian/Pacific Islander | 602 (3.8) | 42 (2.7) | 27 (2.4) | 556 (3.9) |
 Other | 49 (0.3) | 4 (0.3) | 3 (0.3) | 45 (0.3) |
 Unknown | 113 (0.7) | 4 (0.3) | 1 (0.1) | 108 (0.8) |
Ethnicityc | ||||
 Non-Hispanic | 10,902 (93.8) | 1031 (94.7) | 749 (95.4) | 9767 (93.8) |
 Hispanic | 660 (5.7) | 58 (5.3) | 36 (4.6) | 592 (5.7) |
 Unknown | 58 (0.5) | 0 (0) | 0 (0) | 58 (0.6) |
Body mass index, kg/m2, mean (SD) | 28.7 (6.7) | 29.0 (6.8) | 28.8 (6.7) | 28.7 (6.6) |
Ever tobacco use | 5182 (32.4) | 454 (29.1) | 333 (30.0) | 4698 (32.9) |
Stage | ||||
 I | 9348 (58.4) | 998 (63.9) | 715 (64.3) | 8245 (57.7) |
 II | 5350 (33.4) | 457 (29.3) | 322 (29.0) | 4857 (34.0) |
 III | 1306 (8.2) | 107 (6.9) | 75 (6.7) | 1196 (8.4) |
Histology | ||||
 Ductal | 12,271 (76.7) | 1197 (76.6) | 847 (76.2) | 10,965 (76.7) |
 Lobular | 1414 (8.8) | 138 (8.8) | 105 (9.4) | 1268 (8.9) |
 Mixed | 1041 (6.5) | 89 (5.7) | 60 (5.4) | 942 (6.6) |
 Other | 1278 (8.0) | 138 (8.8) | 100 (9.0) | 1123 (7.9) |
ER status | ||||
 Negative | 2674 (16.7) | 255 (16.3) | 170 (15.3) | 2401 (16.8) |
 Positive | 12,746 (79.6) | 1237 (79.2) | 894 (80.4) | 11,397 (79.7) |
 Unknown/borderline | 584 (3.6) | 70 (4.5) | 48 (4.3) | 500 (3.5) |
PR status | ||||
 Negative | 4341 (27.1) | 418 (26.8) | 300 (27.0) | 3889 (27.2) |
 Positive | 10,972 (68.6) | 1055 (67.5) | 753 (67.7) | 9823 (68.7) |
 Unknown/borderline | 691 (4.3) | 89 (5.7) | 59 (5.3) | 586 (4.1) |
HER2 statusd | ||||
 Negative | 2792 (84.5) | 76 (87.4) | 58 (86.6) | 2714 (84.4) |
 Positive | 412 (12.5) | 6 (6.9) | 5 (7.5) | 406 (12.6) |
 Unknown/borderline | 102 (3.1) | 5 (5.8) | 4 (6.0) | 96 (3.0) |
Surgery type | ||||
 Lumpectomy, partial mastectomy | 9772 (61.1) | 994 (63.6) | 694 (62.4) | 8634 (60.4) |
 Mastectomy | 6232 (38.9) | 568 (36.4) | 418 (37.6) | 5664 (39.6) |
Received radiotherapy | ||||
 No | 5302 (33.1) | 507 (32.5) | 381 (34.3) | 4783 (33.5) |
 Yes | 10,638 (66.5) | 1054 (67.5) | 731 (65.7) | 9452 (66.1) |
 Unknown | 64 (0.4) | 1 (0.1) | 0 (0) | 63 (0.4) |
Received chemotherapy | ||||
 No | 9218 (57.6) | 1028 (65.8) | 753 (67.7) | 8097 (56.6) |
 Yes | 6786 (42.4) | 534 (34.2) | 359 (32.3) | 6201 (43.4) |
Received endocrine therapy | ||||
 No | 4805 (30.0) | 563 (36.0) | 363 (32.6) | 4177 (29.2) |
 Yes | 11,199 (70.0) | 999 (64.0) | 749 (67.4) | 10,121 (70.8) |
  Tamoxifen only | 5147 (46.0) | 640 (64.1) | 469 (62.6) | 4448 (44.0) |
  AIs only | 3012 (26.9) | 154 (15.4) | 123 (16.4) | 2850 (28.2) |
  Tamoxifen + AIs | 2611 (23.3) | 167 (16.7) | 127 (17.0) | 2435 (24.1) |
  Other/unknown | 429 (3.8) | 38 (3.8) | 30 (4.0) | 388 (3.8) |