Table 1.
Baseline characteristics of the patients
| Characteristic | Before propensity score matched |
After propensity score matched |
||||
|---|---|---|---|---|---|---|
| Chemotherapy (n=398) | Natural history (n=206) | p-value | Chemotherapy (n=164) | Natural history (n=164) | p-value | |
| Sex | ||||||
| Male | 226 (56.8) | 115 (55.8) | 0.863 | 93 (56.7) | 91 (55.5) | 0.911 |
| Female | 172 (43.2) | 91 (44.2) | 71 (43.3) | 73 (44.5) | ||
| Age | 60.7±10.0 | 69.9±10.6 | < 0.001 | 67.4±6.7 | 67.9±10.1 | 0.592 |
| Extent of disease | ||||||
| locally advanced | 110 (27.7) | 42 (22.7) | 0.224 | 29 (17.7) | 36 (22.0) | 0.406 |
| Metastatic | 287 (72.3) | 143 (77.3) | 135 (82.3) | 128 (78.0) | ||
| ECOG | ||||||
| 0 or 1 | 346 (86.9) | 125 (60.7) | < 0.001 | 116 (70.7) | 109 (66.5) | 0.475 |
| 2 | 52 (13.1) | 81 (39.3) | 48 (29.3) | 55 (33.5) | ||
| CA 19-9 (IU/mL) | ||||||
| ≤ 100 | 175 (48.9) | 84 (43.5) | 0.245 | 63 (42.3) | 67 (43.8) | 0.817 |
| > 100 | 183 (51.1) | 109 (56.5) | 86 (57.7) | 86 (56.2) | ||
| CEA (ng/mL) | ||||||
| ≤ 3.4 | 172 (50.6) | 73 (41.5) | 0.051 | 56 (40.3) | 58 (40.6) | 1.000 |
| > 3.4 | 168 (49.4) | 103 (58.5) | 83 (59.7) | 85 (59.4) | ||
| WBC (cell/mm3) | ||||||
| < 3,500 | 18 (4.5) | 4 (1.9) | 0.050 | 9 (5.5) | 4 (2.4) | 0.311 |
| ≥ 3,500 and < 10,000 | 308 (77.6) | 151 (73.3) | 120 (73.2) | 119 (72.6) | ||
| ≥ 10,000 | 71 (17.9) | 51 (24.8) | 35 (21.3) | 41 (25.0) | ||
| Platelet (×103/mm3) | ||||||
| < 130 | 43 (11.5) | 17 (8.3) | 0.460 | 23 (15.3) | 14 (8.5) | 0.180 |
| ≥ 130 and < 400 | 303 (81) | 174 (84.5) | 115 (76.7) | 136 (82.9) | ||
| ≥ 400 | 28 (7.5) | 15 (7.3) | 12 (8.0) | 14 (8.5) | ||
| Albumin (mg/dL) | ||||||
| ≤ 3.5 | 112 (28.2) | 101 (49) | < 0.001 | 78 (47.6) | 79 (48.2) | 1.000 |
| 3.5-5.2 | 285 (71.8) | 105 (51) | 86 (52.4) | 85 (51.8) | ||
| T.bilirubin (mg/dL) | ||||||
| ≤ 1.2 | 315 (79.3) | 104 (50.5) | < 0.001 | 100 (61.0) | 88 (53.7) | 0.219 |
| > 1.2 | 82 (20.7) | 102 (49.5) | 64 (39.0) | 76 (46.3) | ||
| ALP (IU/L) | ||||||
| ≤ 80 | 70 (17.6) | 31 (15) | 0.490 | 22 (13.4) | 25 (15.2) | 0.753 |
| > 80 | 327 (82.4) | 175 (85) | 142 (86.6) | 139 (84.8) | ||
| AST (IU/L) | ||||||
| ≤ 40 | 275 (69.3) | 100 (48.5) | < 0.001 | 91 (55.5) | 86 (52.4) | 0.658 |
| > 40 | 122 (30.7) | 106 (51.5) | 73 (44.5) | 78 (47.6) | ||
| ALT (IU/L) | ||||||
| ≤ 40 | 291 (73.3) | 111 (53.9) | < 0.001 | 105 (64.0) | 92 (56.1) | 0.176 |
| > 40 | 106 (26.7) | 95 (46.1) | 59 (36.0) | 72 (43.9) | ||
| Origin site | ||||||
| Bile duct | 119 (72.6) | 122 (74.4) | 0.615 | |||
| Ampulla of Vater | 12 (7.3) | 15 (9.1) | ||||
| Gallbladder | 33 (20.1) | 27 (16.5) | ||||
Values are presented as number (%) or mean±standard deviation. ECOG, Eastern Cooperative Oncology Group; CA 19-9, cancer antigen 19-9; CEA, carcinoembryonic antigen; WBC, white blood cell; T.bilirubin, total bilirubin; ALP, alkaline phosphatase; AST, aspartate aminotransferase; ALT, alanine transaminase.