Table 2 . The clinical characteristics of patients with lung metastases according to tumor subtypes.
| Patients characteristics | Tumor subtypes | P value | |||||
|---|---|---|---|---|---|---|---|
| HR+/HER2− | HR+/HER2+ | HR−/HER2+ | Triple-negative | Unknown | Total | ||
| n (%) | n (%) | n (%) | n (%) | n (%) | n (%) | ||
| All patients | 2,940 (45.1) | 852 (13.1) | 547 (8.4) | 983 (15.1) | 1,194 (18.3) | 6,516 (100) | |
| Age at diagnosis, years | <0.001 | ||||||
| 18–40 | 137 (4.7) | 62 (7.3) | 51 (9.3) | 75 (7.6) | 33 (2.8) | 358 (5.5) | |
| 41–60 | 977 (33.2) | 370 (43.4) | 255 (46.6) | 369 (37.5) | 326 (27.3) | 2,297 (35.3) | |
| 61–80 | 1,465 (49.8) | 340 (39.9) | 197 (36.0) | 419 (42.6) | 538 (45.1) | 2,959 (45.4) | |
| >80 | 361 (12.3) | 80 (9.4) | 44 (8.0) | 120 (12.2) | 297 (24.9) | 902 (13.8) | |
| Gender | 0.052 | ||||||
| Male | 54 (1.8) | 16 (1.9) | 2 (0.4) | 8 (0.8) | 18 (1.5) | 98 (1.5) | |
| Female | 2,886 (98.2) | 836 (98.1) | 545 (99.6) | 975 (99.2) | 1,176 (98.5) | 6,418 (98.5) | |
| Race | <0.001 | ||||||
| White | 2,168 (73.7) | 627 (73.6) | 378 (69.1) | 646 (65.7) | 910 (76.2) | 4,729 (72.6) | |
| Black | 508 (17.3) | 151 (17.7) | 107 (19.6) | 260 (26.4) | 207 (17.3) | 1,233 (18.9) | |
| Other | 253 (8.6) | 72 (8.5) | 60 (11.0) | 76 (7.7) | 70 (5.9) | 531 (8.1) | |
| Unknown | 11 (0.4) | 2 (0.2) | 2 (0.4) | 1 (0.1) | 7 (0.6) | 23 (0.4) | |
| Marital status | 0.033 | ||||||
| Single | 678 (23.1) | 193 (22.7) | 116 (21.2) | 209 (21.3) | 289 (24.2) | 1,485 (22.8) | |
| Married/domestic partner | 1,132 (38.5) | 363 (42.6) | 223 (40.8) | 390 (39.7) | 396 (33.2) | 2,504 (38.4) | |
| Divorced/separated/widowed | 958 (32.6) | 251 (29.5) | 170 (31.1) | 329 (33.5) | 433 (36.3) | 2,141 (32.9) | |
| Unknown | 172 (5.9) | 45 (5.3) | 38 (6.9) | 55 (5.6) | 76 (6.4) | 386 (5.9) | |
| Tumor site(s) | <0.001 | ||||||
| Only one site (left or right) | 2,853 (97.0) | 837 (98.2) | 531 (97.1) | 958 (97.5) | 1,050 (87.9) | 6,229 (95.6) | |
| Two or more sites | 87 (3.0) | 15 (1.8) | 16 (2.9) | 25 (2.5) | 144 (12.1) | 287 (4.4) | |
| Tumor grade | <0.001 | ||||||
| I | 228 (7.8) | 20 (2.3) | 1 (0.2) | 9 (0.9) | 23 (1.9) | 281 (4.3) | |
| II | 1,191 (40.5) | 274 (32.2) | 90 (16.5) | 110 (11.2) | 166 (13.9) | 1,831 (28.1) | |
| III | 937 (31.9) | 424 (49.8) | 347 (63.4) | 702 (71.4) | 197 (16.5) | 2,607 (40.0) | |
| IV | 16 (0.5) | 7 (0.8) | 9 (1.6) | 14 (1.4) | 11 (0.9) | 57 (0.9) | |
| Unknown | 568 (19.3) | 127 (14.9) | 100 (18.3) | 148 (15.1) | 797 (66.8) | 1,740 (26.7) | |
| Histology | <0.001 | ||||||
| Ductal | 2,176 (74.0) | 700 (82.2) | 434 (79.3) | 726 (73.9) | 418 (35.0) | 4,455 (68.4) | |
| Lobular | 176 (6.0) | 13 (1.5) | 2 (0.4) | 11 (1.1) | 37 (3.1) | 239 (3.7) | |
| Mixed ductal and lobular | 165 (5.6) | 37 (4.3) | 11 (2.0) | 20 (2.0) | 19 (1.6) | 252 (3.9) | |
| Mucinous | 52 (1.8) | 5 (0.6) | 0 (0) | 1 (0.1) | 5 (0.4) | 63 (1.0) | |
| Carcinoma | 371 (12.6) | 97 (11.4) | 100 (18.3) | 224 (22.8) | 715 (59.9) | 1,507 (23.1) | |
| Extrapulmonary metastatic sites to bone, brain, and liver, No. | <0.001 | ||||||
| 0 | 831 (28.3) | 259 (30.4) | 212 (38.8) | 448 (45.6) | 394 (33.0) | 2,144 (32.9) | |
| 1 | 1,420 (48.3) | 314 (36.9) | 159 (29.1) | 339 (34.5) | 470 (39.4) | 2,702 (41.5) | |
| 2 | 587 (20.0) | 241 (28.3) | 136 (24.9) | 144 (14.6) | 257 (21.5) | 1,365 (20.9) | |
| All 3 | 87 (3.0) | 36 (4.2) | 37 (6.8) | 43 (4.4) | 36 (3.0) | 239 (3.7) | |
| Unknown | 15 (0.5) | 2 (0.2) | 3 (0.5) | 9 (0.9) | 37 (3.1) | 66 (1.0) | |
| Cancer-directed surgery | <0.001 | ||||||
| Performed | 583 (19.8) | 212 (24.9) | 168 (30.7) | 332 (33.8) | 123 (10.3) | 1,418 (21.8) | |
| Not performed | 2,307 (78.5) | 627 (73.6) | 366 (66.9) | 635 (64.6) | 1,043 (87.4) | 4,978 (76.4) | |
| Unknown | 50 (1.7) | 13 (1.5) | 13 (2.4) | 16 (1.6) | 28 (2.3) | 120 (1.8) | |
| Radiation | <0.001 | ||||||
| Yes | 790 (26.9) | 220 (25.8) | 150 (27.4) | 279 (28.4) | 156 (13.1) | 1,595 (24.5) | |
| No | 2,107 (71.7) | 616 (72.3) | 385 (70.4) | 687 (69.9) | 1,034 (86.6) | 4,829 (74.1) | |
| Unknown | 42 (1.4) | 16 (1.9) | 12 (2.2) | 17 (1.7) | 4 (0.3) | 91 (1.4) | |
| Chemotherapy | <0.001 | ||||||
| Yes | 1,241 (42.2) | 610 (71.6) | 410 (75.0) | 683 (69.5) | 304 (25.5) | 3,248 (49.8) | |
| No/unknown | 1,699 (57.8) | 242 (28.4) | 137 (25.0) | 300 (30.5) | 890 (74.5) | 3,268 (50.2) | |
| Status | <0.001 | ||||||
| Alive | 1,335 (45.4) | 460 (54.0) | 245 (44.8) | 230 (23.4) | 254 (21.3) | 2,524 (38.7) | |
| Dead | 1,605 (54.6) | 392 (46.0) | 302 (55.2) | 753 (76.6) | 940 (78.7) | 3,992 (61.3) | |
| Cause of death | <0.001 | ||||||
| Alive | 1,335 (45.4) | 460 (54.0) | 245 (44.8) | 230 (23.4) | 254 (21.3) | 2,524 (38.7) | |
| Breast cancer | 1,357 (46.2) | 343 (40.3) | 261 (47.7) | 669 (68.1) | 740 (62.0) | 3,370 (51.7) | |
| Other | 248 (8.4) | 49 (5.8) | 41 (7.5) | 84 (8.5) | 200 (16.8) | 622 (9.5) | |