Table 2.
Descriptive characteristics of women age ≥55 years at diagnosis of hormone receptor positive breast cancer (2001-2016) by endocrine therapy use within 12 months of diagnosis
| Age ≥55 years (N=5502) | ||||
|---|---|---|---|---|
| Characteristic | Any endocrine therapya N (%) |
Tamoxifen first N (%) |
AIs first N (%) |
No endocrine therapyb N (%) |
| Total | 4338 (78.8) | 1592 (28.9) | 2746 (49.9) | 1164 (21.2) |
| Age at diagnosis, mean (SD) | 67.2 (8.2) | 68.0 (8.6) | 66.7 (7.9) | 72.2 (9.8) |
| Age at diagnosis | ||||
| 55-<65 | 1974 (45.5) | 671 (42.1) | 1303 (47.5) | 319 (27.4) |
| 65-<75 | 1567 (36.1) | 557 (35.0) | 1010 (36.8) | 400 (34.4) |
| ≥75 | 797 (18.4) | 364 (22.9) | 433 (15.8) | 445 (38.2) |
| Year of diagnosis | ||||
| 2001-2004 | 1138 (26.2) | 846 (53.1) | 292 (10.6) | 393 (33.8) |
| 2005-2008 | 1350 (31.1) | 442 (27.8) | 908 (33.1) | 350 (30.1) |
| 2009-2012 | 949 (21.9) | 166 (10.4) | 783 (28.5) | 228 (19.6) |
| 2013-2016 | 901 (20.8) | 138 (8.7) | 763 (27.8) | 193 (16.6) |
| Race | ||||
| White | 4021 (92.7) | 1482 (93.1) | 2539 (92.5) | 1071 (92.0) |
| Black | 95 (2.2) | 29 (1.8) | 66 (2.4) | 37 (3.2) |
| American Indian/Alaska Native | 21 (0.5) | 8 (0.5) | 13 (0.5) | 5 (0.4) |
| Asian/Pacific Islander | 142 (3.3) | 47 (3.0) | 95 (3.5) | 24 (2.1) |
| Other | 21 (0.5) | 7 (0.4) | 14 (0.5) | 4 (0.3) |
| Missing | 38 (0.9) | 19 (1.2) | 19 (0.7) | 23 (2.0) |
| Stage | ||||
| I | 2591 (59.7) | 1012 (63.6) | 1579 (57.5) | 959 (82.4) |
| II | 1420 (32.7) | 508 (31.9) | 912 (33.2) | 181 (15.5) |
| III | 327 (7.5) | 72 (4.5) | 255 (9.3) | 24 (2.1) |
| Histology | ||||
| Ductal | 3242 (74.7) | 1185 (74.4) | 2057 (74.9) | 870 (74.7) |
| Lobular | 509 (11.7) | 178 (11.2) | 331 (12.1) | 102 (8.8) |
| Mixed | 390 (9.0) | 141 (8.9) | 249 (9.1) | 71 (6.1) |
| Other | 197 (4.5) | 88 (5.5) | 109 (4.0) | 121 (10.4) |
| HR Status | ||||
| ER+/PR+ | 3690 (85.1) | 1365 (85.7) | 2325 (84.7) | 969 (83.2) |
| ER+/PR− | 631 (14.5) | 219 (13.8) | 412 (15.0) | 172 (14.8) |
| ER−/PR+ | 17 (0.4) | 8 (0.5) | 9 (0.3) | 23 (2.0) |
| HER2 status | ||||
| Positive | 307 (7.1) | 87 (5.5) | 220 (8.0) | 50 (4.3) |
| Negative | 2500 (57.6) | 825 (51.8) | 1675 (61.0) | 698 (60.0) |
| Missing | 1531 (35.3) | 680 (42.7) | 851 (31.0) | 416 (35.7) |
| Tumor size, cm | ||||
| <1 | 877 (20.2) | 333 (20.9) | 544 (19.8) | 489 (42.0) |
| 1-<2 | 2004 (46.2) | 767 (48.2) | 1237 (45.1) | 461 (39.6) |
| 2-<5 | 1275 (29.4) | 449 (28.2) | 826 (30.1) | 192 (16.5) |
| ≥5 | 149 (3.4) | 27 (1.7) | 122 (4.4) | 15 (1.3) |
| Missing | 33 (0.8) | 16 (1.0) | 17 (0.6) | 7 (0.6) |
| Grade | ||||
| Well differentiated | 1518 (35.0) | 639 (40.1) | 879 (32.0) | 583 (50.1) |
| Moderately differentiated | 2042 (47.1) | 740 (46.5) | 1302 (47.4) | 433 (37.2) |
| Poorly differentiated/undifferentiated | 778 (17.9) | 213 (13.4) | 565 (20.6) | 148 (12.7) |
| Surgical procedure | ||||
| BCS | 280 (6.5) | 111 (7.0) | 169 (6.2) | 198 (17.0) |
| BCS + radiotherapy | 2591 (59.7) | 964 (60.6) | 1627 (59.2) | 637 (54.7) |
| Mastectomy | 1467 (33.8) | 517 (32.5) | 950 (34.6) | 329 (28.3) |
| Chemotherapy | ||||
| No | 3158 (72.8) | 1248 (78.4) | 1910 (69.6) | 1071 (92.0) |
| Yes | 1180 (27.2) | 344 (21.6) | 836 (30.4) | 93 (8.0) |
Abbreviations: HR - Hormone receptor; ER - Estrogen receptor; PR – Progesterone receptor; HER2 - Human epidermal growth factor receptor 2; BCS - Breast conserving surgery (lumpectomy/partial mastectomy)
a
Includes any use of tamoxifen, letrozole, anastrozole, exemestane within 12 months of breast cancer diagnosis
b
Defined as no use of endocrine therapy at any time.