Table 1

Study cohort of patients with breast cancer with BM (N=2427) by stage of disease at BC diagnosis

Stage of disease at BC diagnosis
Localised BC
N=420
N (%)
Regional BC
N=1204
N (%)
Metastatic BC
N=606
N (%)
Unknown
N=197
N (%)
Overall
N=2427
N (%)
Age at BC diagnosis (years)
 25–4994 (22%)319 (27%)89 (15%)30 (15%)532 (22%)
 50–59103 (25%)340 (28%)129 (21%)45 (23%)617 (25%)
 60–69120 (29%)321 (27%)201 (33%)56 (28%)698 (29%)
 ≥70103 (25%)224 (19%)187 (31%)66 (34%)580 (24%)
Time period of BC diagnosis
 1997–2001211 (50%)492 (41%)135 (22%)36 (18%)874 (36%)
 2002–2006161 (38%)528 (44%)242 (40%)80 (41%)1011 (42%)
 2007–201148 (11%)184 (15%)229 (38%)81 (41%)542 (22%)
Hormone receptor and HER2 status
 ER-positive313 (75%)890 (74%)500 (83%)156 (79%)1859 (77%)
 ER-negative99 (24%)295 (25%)98 (16%)35 (18%)527 (22%)
 Unknown8 (2%)19 (2%)8 (1%)6 (3%)41 (2%)
 ER/PR-positive and HER2-negative61 (15%)200 (17%)180 (30%)50 (25%)491 (20%)
 HER2-positive (any ER/PR status)46 (11%)216 (18%)97 (16%)34 (17%)393 (16%)
 ER/PR-negative and HER2-negative42 (10%)128 (11%)51 (8%)17 (9%)238 (10%)
 Unknown271 (65%)660 (55%)278 (46%)96 (49%)1305 (54%)
Charlson Comorbidity Index score
 0316 (75%)925 (77%)476 (79%)145 (74%)1862 (77%)
 1–287 (21%)245 (20%)111 (18%)42 (21%)485 (20%)
 >217 (4%)34 (3%)19 (3%)10 (5%)80 (3%)
Median age (range) at BM diagnosis64 years (28–92)62 years (28–97)65 years (28–95)67 years (34–92)63 years (28–97)
Length of BMFI
 0 to <1 year79 (19%)264 (22%)491 (81%)84 (43%)918 (38%)
 1 to <3 years131 (31%)426 (35%)71 (12%)58 (29%)686 (28%)
 3 to <5 years108 (26%)281 (23%)38 (6%)35 (18%)462 (19%)
 ≥5 years102 (24%)233 (19%)6 (1%)20 (10%)361 (15%)
 25th centile1.43 years1.16 years0.02 years0.12 years0.16 years
 Median3.01 years2.54 years0.07 years1.52 years1.85 years
 75th centile4.87 years4.34 years0.44 years3.30 years3.78 years
Other metastases recorded at or before BM diagnosis200 (48%)691 (57%)296 (49%)105 (53%)1292 (53%)
Skeletal-related events at BM diagnosis*
 Radiation to bone81 (19%)258 (21%)124 (20%)21 (11%)484 (20%)
 Pathological fracture11 (3%)41 (3%)14 (2%)1 (1%)67 (3%)
 Spinal cord compression12 (3%)33 (3%)12 (2%)6 (3%)63 (3%)
 Surgery to bone10 (2%)29 (2%)19 (3%)5 (3%)63 (3%)
  • *Categories not mutually exclusive.

  • BC, breast cancer; BM, bone metastasis; BMFI, bone metastasis-free interval; ER, estrogen receptor; HER2, human epidermal growth factor receptor 2; PR, progesterone receptor.