Table 1.
Comparison of external validation population with development population. Values are n (%) unless otherwise specified
| Variables | Training set Developmental cohort (n = 397) | Validation set |
p-value versus | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Scandinavia (n = 815) | Italy (n = 287) | Japan (n = 261) | Taiwan (n = 356) | developmental cohort | Scandinavia | Italy | Japan | ||
| Age at surgery, mean (SD) | 62.4 (13.7) | 66.4 (12.7) | 63.1 (11.7) | 61.8 (12.3) | 61.2 (12.8) | 0.2 | < 0.01 | 0.1 | 0.6 |
| Sex | 0.1 | 0.3 | 0.1 | 0.2 | |||||
| Male | 170 (43) | 369 (45) | 120 (42) | 139 (53) | 172 (48) | ||||
| Female | 227 (57) | 446 (55) | 167 (58) | 122 (47) | 184 (52) | ||||
| Oncologic diagnosis group a | < 0.001 | < 0.001 | < 0.001 | < 0.001 | |||||
| 1 | 108 (27) | 173 (21) | 63 (22) | 60 (23) | 158 (44) | ||||
| 2 | 72 (18) | 74 (9) | 44 (15) | 75 (29) | 71 (20) | ||||
| 3 | 211 (53) | 567 (69) | 173 (60) | 126 (48) | 127 (36) | ||||
| Missing | 6 (2) | 1 (<1) | 7 (2) | 0 (0) | 0 (0) | ||||
| Visceral metastases | < 0.001 | 0.01 | < 0.001 | 0.1 | |||||
| Yes | 247 (62) | 325 (40) | 91 (32) | 114 (44) | 180 (51) | ||||
| No | 148 (37) | 441 (54) | 161 (56) | 147 (56) | 176 (49) | ||||
| Missing | 2 (<1) | 49 (6) | 35 (12) | 0 (0) | 0 (0) | ||||
| Lymph node metastases | 0.2 | 0.004 | 0.4 | < 0.001 | |||||
| Yes | 152 (38) | 169 (21) | 96 (33) | 71 (27) | 153 (43) | ||||
| No | 245 (62) | 143 (18) | 146 (51) | 190 (73) | 203 (57) | ||||
| Missing | 0 (0) | 503 (62) | 45 (16) | 0 (0) | 0 (0) | ||||
| Skeletal metastases | 1.0 | < 0.001 | < 0.001 | < 0.001 | |||||
| Solitary | 112 (28) | 123 (15) | 139 (48) | 112 (43) | 100 (28) | ||||
| Multiple | 285 (72) | 666 (81) | 144 (50) | 149 (57) | 256 (72) | ||||
| Missing | 0 (0) | 26 (3) | 4 (1) | 0 (0) | 0 (0) | ||||
| Eastern Cooperative Oncology Group performance status score | < 0.001 | < 0.001 | < 0.001 | < 0.001 | |||||
| 0–2 | 222 (56) | 558 (69) | 123 (42) | 166 (64) | 283 (79) | ||||
| 3–4 | 164 (41) | 257 (31) | 106 (37) | 95 (36) | 73 (21) | ||||
| Missing | 11 (3) | 0 (0) | 58 (20) | 0 (0) | 0 (0) | ||||
| Survival > 1 month | 0.9 | < 0.001 | – | 0.1 | |||||
| Yes | 379 (96) | 707 (87) | – | 240 (92) | 339 (95) | ||||
| No | 18 (5) | 108 (13) | – | 21 (8) | 17 (5) | ||||
| Missing | 0 (0) | 0 (0) | – | 0 (0) | 0 (0) | ||||
| Survival > 3 months | 0.3 | < 0.001 | < 0.001 | 0.6 | |||||
| Yes | 309 (78) | 557 (68) | 267 (93) | 218 (84) | 287 (81) | ||||
| No | 88 (22) | 258 (32) | 20 (7) | 43 (17) | 63 (18) | ||||
| Missing | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 6 (2) | ||||
| Survival > 6 months | 0.4 | < 0.001 | – | 1.0 | |||||
| Yes | 248 (63) | 372 (46) | – | 179 (69) | 234 (66) | ||||
| No | 149 (38) | 443 (54) | – | 82 (31) | 108 (30) | ||||
| Missing | 0 (0) | 0 (0) | – | 0 (0) | 14 (4) | ||||
| Survival > 12 months | 0.4 | < 0.001 | < 0.001 | 0.02 | |||||
| Yes | 189 (48) | 241 (30) | 181 (63) | 152 (58) | 159 (45) | ||||
| No | 208 (52) | 574 (70) | 106 (37) | 109 (42) | 167 (47) | ||||
| Missing | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 30 (8) | ||||
| Survival > 18 months | 0.8 | < 0.001 | – | 0.3 | |||||
| Yes | 134 (34) | 156 (19) | – | 113 (43) | 123 (35) | ||||
| No | 263 (66) | 659 (81) | – | 148 (57) | 191 (54) | ||||
| Missing | 0 (0) | 0 (0) | – | 0 (0) | 42 (12) | ||||
| Survival > 24 months | 0.7 | < 0.001 | – | 0.6 | |||||
| Yes | 105 (26) | 117 (14) | – | 79 (30) | 98 (28) | ||||
| No | 292 (74) | 698 (86) | – | 182 (70) | 204 (72) | ||||
| Missing | 0 (0) | 0 (0) | – | 0 (0) | 54 (15) | ||||
| Hemoglobin concentration (mg/dL) | 11 (10–13) b | 11.5 (3.5) | 11.5 (1.4) | 12.4 (6.0) | 11 (2.0) | 0.2 | 0.002 | < 0.001 | < 0.001 |
| Absolute lymphocyte count (K/uL) | 1.2 (1.3) | 1.2 (0.7) | 1.3 (0.5) | 1.3 (0.9) | 1.3 (0.9) | 0.2 | 0.06 | 1 | 1 |
| Surgeon’s estimate of survival (months) | 9 (6–18) b | 11.8 (17.2) | 11.2 (7.0) | 8.9 (4.6) | Not available | – | – | – | – |
| Pathologic fracture status | 0.02 | < 0.001 | 0.5 | < 0.00 | |||||
| Completed | 84 (44) | 614 (75) | 143 (50) | 105 (40) | 195 (55) | ||||
| Impending | 105 (56) | 196 (24) | 131 (46) | 156 (60) | 161 (45) | ||||
| Missing | all RT cases | 5 (1) | 3 (5) | 0 (0) | 0 (0) | ||||
| Preoperative systemic therapy | – | – | – | – | |||||
| Chemotherapy | – | – | – | – | 227 (64) | ||||
| Target therapy | – | – | – | – | 121 (34) | ||||
| Hormone therapy | – | – | – | – | 59 (17) | ||||
| Immunotherapy | – | – | – | – | 24 (7) | ||||
| Preoperative radiotherapy | – | – | – | – | 215 (60) | – | – | – | – |
| Surgical treatment | – | – | – | – | |||||
| Intramedullary nail | – | – | – | – | 210 (59) | ||||
| Plate-and-screws fixation | – | – | – | – | 81 (23) | ||||
| Endoprosthetic reconstruction | – | – | – | – | 65 (18) | ||||
a
Cancer types of pulmonary, gastric, and hepatoma and melanoma were assigned to Group 1; sarcomas and other carcinomas carcinomas were assigned to Group 2; breast, prostate, thyroid cancer, renal cell carcinoma, multiple myeloma, and malignant lymphoma were assigned to Group 3.
b
The original article provided only IQR without SD.