Patients’ characteristics
| Clinicopathologic variables | Total (%) | 5-FU-based for first-line therapy (%) | Gem-based for first-line therapy (%) | P |
|---|---|---|---|---|
| n | 1,054 | 437 | 617 | |
| Age (years) | ||||
| ≤ 63 | 574 (54.5) | 215 (49.2) | 359 (58.2) | 0.005* |
| > 63 | 480 (45.5) | 222 (50.8) | 258 (41.8) | |
| Gender | ||||
| Female | 472 (44.8) | 205 (46.9) | 267 (43.3) | 0.268 |
| Male | 582 (55.2) | 232 (53.1) | 350 (56.7) | |
| ECOG performance status | ||||
| 0–2 | 818 (77.6) | 349 (79.9) | 469 (76.0) | 0.161 |
| ≥ 3 | 236 (22.4) | 88 (20.1) | 148 (24.0) | |
| CA19-9 (U/mL) | ||||
| ≤ 200 | 460 (43.6) | 179 (41.0) | 281 (45.5) | 0.157 |
| > 200 | 594 (56.4) | 258 (59.0) | 336 (54.5) | |
| Primary tumor size (cm) | ||||
| ≤ 4 | 527 (50.0) | 210 (48.1) | 317 (51.4) | 0.317 |
| > 4 | 527 (50.0) | 227 (51.9) | 300 (48.6) | |
| Metastatic lesion size [mean (SD), cm] | ||||
| 3.06 (1.30) | 2.99 (1.33) | 3.11 (1.27) | 0.145 | |
| Location | ||||
| Pancreas other than the pancreatic head | 357 (33.9) | 141 (32.3) | 216 (35.0) | 0.389 |
| Pancreatic head | 697 (66.1) | 296 (67.7) | 401 (65.0) | |
| Distant metastasis | ||||
| Absent | 97 (9.2) | 40 (9.2) | 57 (9.2) | > 0.999 |
| Present | 957 (90.8) | 397 (90.8) | 560 (90.8) | |
| Liver metastasis | ||||
| Absent | 374 (35.5) | 173 (39.6) | 201 (32.6) | 0.023* |
| Present | 680 (64.5) | 264 (60.4) | 416 (67.4) | |
| Lung metastasis | ||||
| Absent | 740 (70.2) | 303 (69.3) | 437 (70.8) | 0.651 |
| Present | 314 (29.8) | 134 (30.7) | 180 (29.2) | |
| Bone metastasis | ||||
| Absent | 933 (88.5) | 385 (88.1) | 548 (88.8) | 0.794 |
| Present | 121 (11.5) | 52 (11.9) | 69 (11.2) | |
| Peritoneal metastasis | ||||
| Absent | 804 (76.3) | 336 (76.9) | 468 (75.9) | 0.752 |
| Present | 250 (23.7) | 101 (23.1) | 149 (24.1) | |
| Lymph node metastasis | ||||
| Absent | 635 (60.2) | 272 (62.2) | 363 (58.8) | 0.294 |
| Present | 419 (39.8) | 165 (37.8) | 254 (41.2) | |
| Optimal effect | ||||
| PD | 293 (27.8) | 116 (26.5) | 177 (28.7) | 0.745 |
| PR | 105 (10.0) | 44 (10.1) | 61 (9.9) | |
| SD | 656 (62.2) | 277 (63.4) | 379 (61.4) | |
ECOG, Eastern Cooperative Oncology Group performance status before second-line therapy; PD, progressive disease; PR, partial response; SD, stable disease. *P < 0.05 was considered statistically significant.