Table 1. Characteristics of the study population.
| Characteristic | Development set (n = 335) | Test set (n = 194) | P | ||
|---|---|---|---|---|---|
| Mean age, yrs* | 64.3 ± 9.3 | 65.9 ± 9.1 | 0.05 | ||
| Sex, male | 198 (59.1) | 103 (53.1) | 0.18 | ||
| Body mass index, kg/m2* | 23.2 ± 3.2 | 23.2 ± 3.3 | 0.82 | ||
| Laboratory results† | |||||
| CA 19-9, U/mL | 76.2 (22.2–276.0) | 59.6 (17.0–205.6) | 0.21 | ||
| Bilirubin, mg/dL | 0.6 (0.4–1.1) | 0.5 (0.4–0.8) | 0.08 | ||
| Albumin, g/dL | 3.6 (3.3–3.8) | 3.6 (3.4–3.8) | 0.74 | ||
| Lymphocyte, 109/L | 1.8 (1.5–2.3) | 1.8 (1.4–2.2) | 0.14 | ||
| Platelet, 109/L | 223 (186–276) | 211 (186.0–252.8) | 0.14 | ||
| Alkaline phosphatase, IU/L | 81 (59.5–129.0) | 75 (59.3–101.8) | 0.10 | ||
| C-reactive protein, mg/dL | 0.1 (0.1–0.5) | 0.1 (0.1–0.3) | 0.06 | ||
| Imaging findings | |||||
| Tumor size, cm* | 2.7 ± 1.0 | 2.6 ± 0.9 | 0.37 | ||
| Dominant tumor location | 0.49 | ||||
| Head | 204 (60.9) | 110 (56.7) | |||
| Body | 62 (18.5) | 44 (22.7) | |||
| Tail | 69 (20.6) | 40 (20.6) | |||
| Adjacent organ invasion | 102 (30.4) | 57 (29.4) | 0.80 | ||
| Tumor SUVmax† | 5.2 (3.9–7.0) | 4.9 (3.5–6.6) | 0.36 | ||
| Suspicious regional LN | 84 (25.1) | 42 (21.6) | 0.37 | ||
| Possible metastasis on 18F-FDG PET/CT | 8 (2.4) | 3 (1.5) | 0.51 | ||
| Type of pancreatic resection | 0.57 | ||||
| Pancreaticoduodenectomy | 202 (60.3) | 108 (55.7) | |||
| Distal pancreatectomy | 126 (37.6) | 81 (41.8) | |||
| Total pancreatectomy | 7 (2.1) | 5 (2.6) | |||
| Additional resection | |||||
| Vein resection | 53 (15.8) | 21 (10.8) | 0.11 | ||
| Artery resection | 8 (2.4) | 3 (1.5) | 0.51 | ||
| Metastatectomy | 7 (2.1) | 2 (1.0) | 0.36 | ||
| Negative resection margin (R0) | 258 (77.0) | 163 (84.0) | 0.05 | ||
| AJCC pathological tumor stage | 0.08 | ||||
| 1A | 37 (11.0) | 35 (18.0) | |||
| 1B | 96 (28.7) | 57 (29.4) | |||
| 2A | 17 (5.1) | 11 (5.7) | |||
| 2B | 128 (38.2) | 73 (37.6) | |||
| 3 | 50 (14.9) | 16 (8.2) | |||
| 4 | 7 (2.1) | 2 (1.0) | |||
| Follow-up data | |||||
| Follow-up duration, mos† | 79.0 (66.6–89.8) | 42.2 (35.2–49.1) | < 0.001 | ||
| Recurrence-free survival, mos† | 12.0 (5.9–33.4) | 14.6 (7.3–31.4) | < 0.001 | ||
| Overall survival, mos† | 33.0 (16.1–61.0) | 33.6 (21.1–43.1) | < 0.001 | ||
Unless otherwise indicated, data are numbers, with percentages in parentheses.
*Data are expressed as means ± standard deviation, †Data are expressed as medians, with interquartile ranges in parentheses. CA 19-9 = carbohydrate antigen 19-9, SUVmax = maximum standardized uptake value, LN = lymph node, 18F-FDG = fluorine-18-fluorodeoxyglucose, AJCC = American Joint Committee on Cancer