Characteristics | Training cohort (n = 160) | External test cohort (n = 47) | P (Inter) | ||||
---|---|---|---|---|---|---|---|
TSR-low (n = 72) | TSR-high (n = 88) | P (Intra) | TSR-low (n = 20) | TSR-high (n = 27) | P (Intra) | ||
Clinical characteristics | |||||||
Age (years), mean ± SD | 60.40 ± 9.45 | 60.55 ± 9.66 | 0.925 | 59.48 ± 9.04 | 59.85 ± 9.25 | 0.892 | 0.784 |
Gender | Â | Â | 0.720 | Â | Â | 0.726 | 0.895 |
 Female | 24 (33.3) | 27 (30.7) |  | 5 (25.0) | 8 (29.6) |  |  |
 Male | 48 (66.7) | 61 (69.3) |  | 15 (75.0) | 19 (70.4) |  |  |
Abdominal pain | Â | Â | 0.106 | Â | Â | 0.770 | 0.592 |
 Yes | 37 (51.4) | 34 (38.6) |  | 9 (45.0) | 11 (40.7) |  |  |
 No | 35 (48.6) | 54 (61.4) |  | 11 (55.0) | 16 (59.3) |  |  |
Pancreatitis history | Â | Â | 0.302 | Â | Â | 0.640 | 0.611 |
 No | 55 (76.4) | 73 (83.0) |  | 16 (80.0) | 23 (85.2) |  |  |
 Yes | 17 (23.6) | 15 (17.0) |  | 4 (20.0) | 4 (14.8) |  |  |
Jaundice | Â | Â | 0.806 | Â | Â | 0.380 | 0.457 |
 No | 56 (77.8) | 67 (76.1) |  | 15 ((75.0) | 23 (85.2) |  |  |
 Yes | 16 (22.2) | 21 (23.9) |  | 5 (25.0) | 4 (14.8) |  |  |
Pathological characteristics | Â | ||||||
 T stage |  |  | 0.048* |  |  | 0.095 | 0.301 |
  T1–2 | 61 (84.7) | 63 (71.6) |  | 17 (85.0) | 17 (63.0) |  |  |
  T3–4 | 11 (15.3) | 25 (28.4) |  | 3 (15.0) | 10 (37.0) |  |  |
 Histological grade |  |  | 0.829 |  |  | 0.013* | 0.052 |
  Low-grade | 47 (65.3) | 56 (63.6) |  | 14 (70.0) | 9 (33.3) |  |  |
  High-grade | 25 (34.7) | 32 (36.4) |  | 6 (30.0) | 18 (66.7) |  |  |
 Lymph node metastasis |  |  | 0.423 |  |  | 0.638 | 0.413 |
  Negative | 43 (59.7) | 47 (53.4) |  | 12 (60.0) | 18 (66.7) |  |  |
  Positive | 29 (40.3) | 41 (46.6) |  | 8 (40.0) | 9 (33.3) |  |  |
 Duodenum invasion |  |  | 0.112 |  |  | 0.333 | 0.599 |
  Negative | 41 (56.9) | 39 (44.3) |  | 9 (45.0) | 16 (59.3) |  |  |
  Positive | 31 (43.1) | 49 (55.7) |  | 11 (55.0) | 11 (40.7) |  |  |
Imaging characteristics | |||||||
 CT-reported tumor size | 26.65 ± 11.31 | 28.57 ± 10.43 | 0.270 | 24.78 ± 17.31 | 29.95 ± 8.78 | 0.228 | 0.772 |
 Location |  |  | 0.173 |  |  | 0.905 | 0.850 |
  Head and neck | 50 (69.4) | 73 (83.0) |  | 13 (65.0) | 18 (66.7) |  |  |
  Body and tail | 22 (30.6) | 15 (17.0) |  | 7 (35.0) | 9 (33.3) |  |  |
 Parenchymal atrophy |  |  | 0.946 |  |  | 0.642 | 0.368 |
  No | 27 (38.0) | 33 (37.5) |  | 9 (45.0) | 14 (51.9) |  |  |
  Yes | 44 (62.0) | 55 (62.5) |  | 11 (55.0) | 13 (48.1) |  |  |
 PD dilatation |  |  | 0.493 |  |  | 0.635 | 0.859 |
  No | 18 (25.0) | 18 (20.5) |  | 4 (20.0) | 7 (25.9) |  |  |
  Yes | 54 (75.0) | 70 (79.5) |  | 16 (80.0) | 20 (74.1) |  |  |
 CBD dilatation |  |  | 0.607 |  |  | 0.381 | 0.914 |
  No | 24 (33.3) | 26 (29.5) |  | 5 (25.0) | 10 (37.0) |  |  |
  Yes | 48 (66.7) | 62 (70.5) |  | 15 (75.0) | 17 (63.0) |  |  |
Biochemical characteristics | Â | ||||||
 CA-199 level |  |  | 0.167 |  |  | 0.260 | 0.774 |
  Normal | 27 (18.1) | 24 (35.2) |  | 2 (10.0) | 11 (40.7) |  |  |
  Abnormal | 45 (81.9) | 64 (64.8) |  | 18 (90.0) | 16 (59.3) |  |  |
 CEA level |  |  | 0.626 |  |  | 0.404 | 0.378 |
  Normal | 61 (84.7) | 72 (81.8) |  | 17 (85.0) | 25 (92.6) |  |  |
  Abnormal | 11 (15.3) | 26 (18.2) |  | 3 (15.0) | 2 (7.4) |  |  |
 TBIL level |  |  | 0.274 |  |  | 0.689 | 0.699 |
  Normal | 34 (47.2) | 34 (38.6) |  | 7 (35.0) | 11 (40.7) |  |  |
  Abnormal | 38 (52.8) | 54 (61.4) |  | 13 (65.0) | 16 (59.3) |  |  |