Table 1.
Baseline demographics and breast cancer-related variables with group comparisons across the different treatments received
| Variable | Categories | Overall | No treatment for both | Treatment for BM only | Treatment for BC only | Treatment for both | p-value |
|---|---|---|---|---|---|---|---|
| N (%) | 9005 (100) | 1594 (17.7%) | 859 (9.5%) | 3027 (33.6%) | 3525 (39.1%) | ||
|
Age (years) N (%) |
≤ 50 | 1854 (20.6) | 187 (11.7) | 123 (14.3) | 691 (22.8) | 853 (24.2) | < 0.001 |
| 51–60 | 2510 (27.9) | 341 (21.4) | 232 (27.0) | 873 (28.8) | 1064 (30.2) | ||
| 61–70 | 2732 (30.3) | 470 (29.5) | 276 (32.1) | 912 (30.1) | 1074 (30.5) | ||
| ≥ 70 | 1909 (21.2) | 596 (37.4) | 228 (26.5) | 551 (18.2) | 534 (15.1) | ||
|
Sex N (%) |
Female | 8904 (98.9) | 1577 (98.9) | 852 (99.2) | 2993 (98.9) | 3482 (98.8) | 0.7821 |
| Male | 101 (1.1) | 17 (1.1) | 7 (0.8) | 34 (1.1) | 43 (1.2) | ||
|
Race N (%), n = 8919 |
Black | 1671 (18.7) | 329 (20.9) | 187 (22.1) | 522 (17.4) | 633 (18.1) | 0.0071 |
| Other | 415 (4.7) | 69 (4.4) | 32 (3.8) | 154 (5.1) | 160 (4.6) | ||
| White | 6833 (76.6) | 1177 (74.7) | 628 (74.1) | 2329 (77.5) | 2699 (77.3) | ||
|
Ethnicity N (%), n = 8764 |
Hispanic | 664 (7.6) | 106 (6.9) | 61 (7.3) | 241 (8.2) | 256 (7.5) | 0.4304 |
| Non-Hispanic | 8100 (92.4) | 1434 (93.1) | 778 (92.7) | 2707 (91.8) | 3181 (92.5) | ||
| Insurance status N (%), n = 8768 | Medicaid | 1439 (16.4) | 206 (13.4) | 114 (13.7) | 512 (17.4) | 607 (17.6) | < 0.0001 |
| Medicare | 3332 (38.0) | 800 (51.9) | 400 (48.0) | 1025 (34.9) | 1107 (32.0) | ||
| Not insured | 655 (7.5) | 144 (9.3) | 67 (8.0) | 215 (7.3) | 229 (6.6) | ||
| Private insurance/managed care | 3342 (38.1) | 391 (25.4) | 253 (30.3) | 1183 (40.3) | 1515 (43.8) | ||
| Facility type N (%), n = 8449 | Academic/research program | 3003 (35.5) | 495 (32.1) | 300 (35.8) | 998 (35.8) | 1210 (36.8) | 0.0976 |
| Community cancer program | 742 (8.8) | 149 (9.7) | 79 (9.4) | 253 (9.1) | 261 (8.0) | ||
| Comprehensive community cancer program | 3315 (39.2) | 643 (41.7) | 323 (38.6) | 1085 (38.9) | 1264 (38.5) | ||
| Integrated network cancer program | 1389 (16.4) | 254 (16.5) | 135 (16.1) | 451 (16.2) | 549 (16.7) | ||
|
Median income quartiles 2012–2016 N (%), n = 8092 |
< $40,227 | 1758 (21.7) | 337 (23.3) | 179 (23.2) | 581 (21.2) | 661 (21.0) | 0.0096 |
| $4022–$50,353 | 1810 (22.4) | 327 (22.6) | 186 (24.1) | 580 (21.3) | 717 (22.8) | ||
| $50,354–$63,332 | 1901 (23.5) | 354 (24.5) | 168 (21.8) | 609 (22.3) | 770 (24.5) | ||
| > $63,333 | 2623 (32.4) | 428 (29.6) | 238 (30.9) | 960 (35.2) | 997 (31.7) | ||
| Percent no high school degree quartiles 2012–2016 N (%), n = 8112 | < 6.3% | 1675 (20.6) | 265 (18.3) | 138 (17.8) | 602 (22.0) | 670 (21.2) | 0.0025 |
| 6.3%–10.8% | 2204 (27.2) | 382 (26.4) | 188 (24.3) | 751 (27.5) | 883 (28.0) | ||
| 10.9%–17.5% | 2189 (27.0) | 402 (27.8) | 224 (28.9) | 730 (26.7) | 833 (26.4) | ||
| > 17.6% | 2044 (25.2) | 398 (27.5) | 224 (28.9) | 651 (23.8) | 771 (24.4) | ||
|
Year of diagnosis N (%) |
2010 | 696(7.7) | 127(8.0) | 72(8.4) | 240(7.9) | 257(7.3) | 0.1797 |
| 2011 | 741(8.2) | 135(8.5) | 80(9.3) | 238(7.9) | 288(8.2) | ||
| 2012 | 728(8.1) | 132(8.3) | 73(8.5) | 261(8.6) | 262(7.4) | ||
| 2013 | 756(8.4) | 117(7.3) | 74(8.6) | 271(9.0) | 294(8.3) | ||
| 2014 | 806(9.0) | 123(7.7) | 71(8.3) | 293(9.7) | 319(9.1) | ||
| 2015 | 851(9.5) | 150(9.4) | 77(9.0) | 308(10.2) | 316(9.0) | ||
| 2016 | 845(9.4) | 163(10.2) | 60(7.0) | 269(8.9) | 353(10.0) | ||
| 2017 | 824(9.2) | 156(9.8) | 71(8.3) | 282(9.3) | 315(8.9) | ||
| 2018 | 916(10.1) | 171(10.7) | 88(10.2) | 289(9.5) | 368(10.4) | ||
| 2019 | 923(10.2) | 157(9.9) | 96(11.2) | 285(9.4) | 385(10.9) | ||
| 2020 | 919(10.2) | 163(10.2) | 97(11.2) | 291(9.6) | 368(10.4) | ||
|
Histology N (%) |
Ductal | 5844 (64.9) | 851 (53.4) | 518 (60.3) | 2044 (67.5) | 2431 (69.0) | < 0.001 |
| Lobular | 590 (6.6) | 90 (5.6) | 39 (4.5) | 241 (8.0) | 220 (6.2) | ||
| Other | 2571 (28.6) | 653 (41.0) | 302 (35.2) | 742 (24.5) | 874 (24.8) | ||
|
Grade N (%), n = 6085 |
1 | 916(15.1) | 131(14.8) | 61(11.8) | 383(17.4) | 341(13.7) | < 0.001 |
| 2 | 2525(41.5) | 348(39.4) | 186(36.1) | 924(42.0) | 1067(43.0) | ||
| 3 | 2644(43.4) | 405(45.8) | 269(52.1) | 894(40.6) | 1076(43.3) | ||
| Tumor size N (%), n = 6561 | < 1 cm | 538 (8.2) | 74 (7.2) | 53 (8.8) | 175 (7.8) | 236 (8.8) | 0.0002 |
| 1–2 cm | 909 (13.9) | 145 (14.0) | 105 (17.4) | 279 (12.3) | 380 (14.2) | ||
| 2–3 cm | 989 (15.1) | 148 (14.3) | 116 (19.3) | 360 (16.0) | 365 (13.7) | ||
| > 3 cm | 4125 (62.8) | 666 (64.5) | 328 (54.5) | 1443 (63.9) | 1688 (63.2) | ||
|
Lympho-vascular invasion N (%), n = 2711 |
0 | 1742(64.3) | 237(63.5) | 134(61.2) | 655(66.0) | 716(63.5) | 0.4583 |
| 1 | 969(35.7) | 136(36.5) | 85(38.8) | 337(34.0) | 411(36.5) | ||
|
Charlson Deyo score N (%) |
0 | 7178 (79.7) | 1196 (75.0) | 637 (74.2) | 2477 (81.8) | 2868 (81.4) | < 0.001 |
| 1 | 1222 (13.6) | 232 (14.6) | 138 (16.1) | 401 (13.2) | 451 (12.8) | ||
| 2 | 370 (4.1) | 91 (5.7) | 54 (6.3) | 90 (3.0) | 135 (3.8) | ||
| ≥ 3 | 235 (2.6) | 75 (4.7) | 30 (3.5) | 59 (1.9) | 71 (2.0) | ||
|
Breast cancer subtype N (%), n = 7563 |
HR ( − )/HER2 ( − ) | 1708 (22.6) | 319 (30.0) | 285 (42.3) | 422 (15.7) | 682 (21.7) | < 0.001 |
| HR ( − )/HER2 ( +) | 956 (12.6) | 122 (11.5) | 91 (13.5) | 285 (10.6) | 458 (14.6) | ||
| HR ( +)/HER2 ( − ) | 3627 (48.0) | 482 (45.3) | 208 (30.9) | 1514 (56.4) | 1423 (45.3) | ||
| HR ( +)/HER2 ( +) | 1272 (16.8) | 140 (13.2) | 90 (13.3) | 464 (17.3) | 578 (18.4) | ||
|
Number of extracranial metastatic sites N (%), n = 8979 |
Brain + 1 metastatic site | 2808 (31.3) | 476 (30.1) | 241 (28.3) | 1037 (34.3) | 1054 (29.9) | < 0.001 |
| Brain + 2 metastatic sites | 2504 (27.9) | 397 (25.1) | 211 (24.8) | 947 (31.3) | 949 (27.0) | ||
| Brain + ≥ 3 metastatic sites | 2258 (25.1) | 450 (28.5) | 175 (20.5) | 776 (25.7) | 857 (24.3) | ||
| Only brain | 1409 (15.7) | 258 (16.3) | 225 (26.4) | 265 (8.7) | 661 (18.8) | ||
|
Location of extracranial metastatic sites N (%), n = 8979 |
Bone | 1786 (19.8) | 283 (17.9) | 109 (12.8) | 799 (26.4) | 595 (16.9) | < 0.001 |
| Bone + liver | 696 (7.8) | 102 (6.4) | 53 (6.2) | 314 (10.4) | 227 (6.5) | ||
| Bone + liver + lung | 908 (10.1) | 183 (11.6) | 63 (7.4) | 331 (10.9) | 331 (9.4) | ||
| Bone + lung | 1038 (11.6) | 169 (10.7) | 71 (8.3) | 380 (12.6) | 418 (11.9) | ||
| Liver | 184 (2.1) | 30 (1.9) | 18 (2.1) | 61 (2.0) | 75 (2.1) | ||
| Liver + lung | 264 (2.9) | 50 (3.2) | 36 (4.2) | 75 (2.5) | 103 (2.9) | ||
| Lung | 689 (7.7) | 141 (8.9) | 91 (10.7) | 137 (4.5) | 320 (9.1) | ||
| Only brain | 1409 (15.7) | 258 (16.3) | 225 (26.4) | 265 (8.8) | 661 (18.8) | ||
| Other | 2005 (22.3) | 365 (23.1) | 186 (21.8) | 663 (21.9) | 791 (22.4) | ||
| Brain metastasis treatment modality N (%), n = 9004 | No treatment | 4620 (51.3) | 1594 (100.0) | 0 (0.0) | 3026 (100.0) | 0 (0.0) | < 0.001 |
| SRS | 827 (9.2) | 0 (0.0) | 122 (14.2) | 0 (0.0) | 705 (20.0) | ||
| WBRT | 2596 (28.8) | 0 (0.0) | 505 (58.7) | 0 (0.0) | 2091 (59.3) | ||
| Surgery | 445 (4.9) | 0 (0.0) | 150 (17.5) | 0 (0.0) | 295 (8.4) | ||
| Surgery + SRS | 311 (3.5) | 0 (0.0) | 53 (6.2) | 0 (0.0) | 258 (7.3) | ||
| Surgery + WBRT | 205 (2.3) | 0 (0.0) | 29 (3.4) | 0 (0.0) | 176 (5.0) | ||
| Breast cancer treatment modality N (%), n = 8991 | No treatment | 2439 (27.1) | 1586 (100.0) | 853 (100.0) | 0 (0.0) | 0 (0.0) | < 0.001 |
| Immunotherapy | 98 (1.1) | 0 (0.0) | 0 (0.0) | 49 (1.6) | 49 (1.4) | ||
| Chemotherapy | 2101 (23.4) | 0 (0.0) | 0 (0.0) | 894 (29.5) | 1207 (34.2) | ||
| Hormonal therapy | 1434 (16.0) | 0 (0.0) | 0 (0.0) | 753 (24.9) | 681 (19.3) | ||
| Immunotherapy + hormonal therapy | 199 (2.2) | 0 (0.0) | 0 (0.0) | 112 (3.7) | 87 (2.5) | ||
| Chemotherapy + hormonal therapy | 1390 (15.5) | 0 (0.0) | 0 (0.0) | 695 (23.0) | 695 (19.7) | ||
| Chemotherapy + immunotherapy | 912 (10.1) | 0 (0.0) | 0 (0.0) | 340 (11.2) | 572 (16.2) | ||
| Chemotherapy + hormonal therapy + immunotherapy | 418 (4.6) | 0 (0.0) | 0 (0.0) | 184 (6.1) | 234 (6.6) |