Table 2.
Study cohort of patients with BC with BM (N=2427) by length of BM-free interval
| Length of BM-free interval |
|||||
|---|---|---|---|---|---|
| 0 to <1year N=918 N (%) |
1 to <3 years N=686 N (%) |
3 to <5 years N=462 N (%) |
≥5 years N=361 N (%) |
Overall N=2427 N (%) |
|
| Age at BC diagnosis (years) | |||||
| 25–49 | 146 (16%) | 158 (23%) | 126 (27%) | 102 (28%) | 532 (22%) |
| 50–59 | 209 (23%) | 187 (27%) | 111 (24%) | 110 (30%) | 617 (25%) |
| 60–69 | 277 (30%) | 197 (29%) | 145 (31%) | 79 (22%) | 698 (29%) |
| ≥70 | 286 (31%) | 144 (21%) | 80 (17%) | 70 (19%) | 580 (24%) |
| Time period of BC diagnosis | |||||
| 1997–2001 | 214 (23%) | 215 (31%) | 198 (43%) | 247 (68%) | 874 (36%) |
| 2002–2006 | 377 (41%) | 311 (45%) | 209 (45%) | 114 (32%) | 1011 (42%) |
| 2007–2011 | 327 (36%) | 160 (23%) | 55 (12%) | 0 (0%) | 542 (22%) |
| Stage of disease at BC diagnosis | |||||
| Localised | 79 (9%) | 131 (19%) | 108 (23%) | 102 (28%) | 420 (17%) |
| Regional | 264 (29%) | 426 (62%) | 281 (61%) | 233 (65%) | 1204 (50%) |
| Metastatic | 491 (53%) | 71 (10%) | 38 (8%) | 6 (2%) | 606 (25%) |
| Unknown | 84 (9%) | 58 (8%) | 35 (8%) | 20 (6%) | 197 (8%) |
| Hormone receptor and HER2 status | |||||
| ER-positive | 714 (78%) | 474 (69%) | 367 (79%) | 304 (84%) | 1859 (77%) |
| ER-negative | 188 (20%) | 199 (29%) | 89 (19%) | 51 (14%) | 527 (22%) |
| Unknown | 16 (2%) | 13 (2%) | 6 (1%) | 6 (2%) | 41 (2%) |
| ER/PR-positive and HER2-negative | 233 (25%) | 135 (20%) | 84 (18%) | 39 (11%) | 491 (20%) |
| HER2-positive (any ER/PR status) | 156 (17%) | 131 (19%) | 72 (16%) | 34 (9%) | 393 (16%) |
| ER/PR-negative and HER2-negative | 90 (10%) | 91 (13%) | 41 (9%) | 16 (4%) | 238 (10%) |
| Unknown | 439 (48%) | 329 (48%) | 265 (57%) | 272 (75%) | 1305 (54%) |
| Charlson Comorbidity Index score | |||||
| 0 | 717 (78%) | 521 (76%) | 341 (74%) | 283 (78%) | 1862 (77%) |
| 1–2 | 173 (19%) | 141 (21%) | 104 (23%) | 67 (19%) | 485 (20%) |
| >2 | 28 (3%) | 24 (4%) | 17 (4%) | 11 (3%) | 80 (3%) |
| Median age (range) at BM diagnosis | 64 years (28–95) | 62 years (28–91) | 63 years (29–97) | 65 years (36–92) | 63 years (28–97) |
| Other metastases recorded at or before BM diagnosis | 437 (48%) | 352 (51%) | 283 (61%) | 220 (61%) | 1292 (53%) |
| Skeletal-related events at BM diagnosis* | |||||
| Radiation to bone | 159 (17%) | 140 (20%) | 112 (24%) | 73 (20%) | 484 (20%) |
| Pathological fracture | 10 (1%) | 26 (4%) | 14 (3%) | 17 (5%) | 67 (3%) |
| Spinal cord compression | 13 (1%) | 19 (3%) | 18 (4%) | 13 (4%) | 63 (3%) |
| Surgery to bone | 18 (2%) | 24 (4%) | 11 (2%) | 10 (3%) | 63 (3%) |
*Categories not mutually exclusive.
BC, breast cancer; BM, bone metastasis; ER, estrogen receptor; HER2, human epidermal growth factor receptor 2; PR, progesterone receptor.