Comparison of the baseline patient characteristics among the adjuvant treatment groups
| Characteristics | Stage II (n = 381) | Stage III–IV (n = 352) | ||||||
|---|---|---|---|---|---|---|---|---|
| No-AT (n = 258) | CTx (n = 82) | CRT (n = 41) | P value | No-AT (n = 114) | CTx (n = 133) | CRT (n = 105) | P value | |
| Gender, n (%) | ||||||||
| Male | 113 (44) | 33 (40) | 22 (54) | 0.364* | 44 (39) | 55 (41) | 43 (41) | 0.897* |
| Female | 145 (56) | 49 (60) | 19 (46) | 70 (61) | 78 (59) | 62 (59) | ||
| Age (years) | ||||||||
| Median [range] | 67 [29–87] | 61 [29–88] | 66 [44–81] | 0.000† | 71 [41–91] | 62 [38–87] | 63 [26–83] | 0.000† |
| ≤60 years, n (%) | 53 (21) | 36 (44) | 10 (24) | 0.000* | 22 (19) | 52 (39) | 39 (37) | 0.002* |
| >60 years, n (%) | 205 (79) | 46 (56) | 31 (76) | 92 (81) | 81 (61) | 66 (63) | ||
| Tumor size (cm) | ||||||||
| Median [range] | 2.3 [0.1–8.8] | 2.7 [0.7–9.0] | 2.5 [0.5–10.5] | 0.420† | 3.4 [1.0–13] | 3.5 [0.9–13.0] | 3.5 [1.0–9.0] | 0.534† |
| ≤3 cm, n (%) | 79 (67) | 38 (63) | 22 (65) | 0.846* | 35 (43) | 34 (44) | 37 (47) | 0.866* |
| >3 cm, n (%) | 38 (33) | 22 (37) | 12 (35) | 47 (57) | 43 (56) | 42 (53) | ||
| T classification, n (%) | ||||||||
| T2 | 258 (100) | 82 (100) | 41 (100) | – | 44 (39) | 58 (44) | 48 (46) | 0.554* |
| T3–4 | – | – | – | 70 (61) | 75 (56) | 57 (54) | ||
| N classification, n (%) | ||||||||
| Nx | 52 (20) | 11 (13) | 3 (7) | 0.075‡ | 8 (7) | 2 (2) | 1 (1) | 0.027‡ |
| N0 | 206 (80) | 71 (87) | 38 (93) | 27 (24) | 25 (19) | 17 (16) | ||
| N1 | 60 (53) | 90 (68) | 74 (71) | |||||
| N2 | 19 (17) | 16 (12) | 13 (12) | |||||
| Preop CA 19-9 level (U/mL) | ||||||||
| Median [range] | 10 [0.1–2,400] | 9 [0.8–383] | 10 [2–119] | 0.347† | 21 [0.1–2,960] | 21 [0.1–8,340] | 19 [0.1–9,410] | 0.370† |
| ≤37 U/mL, n (%) | 168 (83) | 57 (84) | 29 (85) | 0.926* | 59 (64) | 81 (68) | 60 (67) | |
| >37 U/mL, n (%) | 35 (17) | 11 (16) | 5 (15) | 34 (37) | 39 (33) | 29 (33) | ||
| Postop CA 19-9 level (U/mL) | ||||||||
| Median [range] | 8 [0.1–3,056] | 8 [0.7–62] | 9 [2.6–606] | 0.639† | 13 [0.1–3,487] | 15 [0.1–850] | 14 [0.1–1,445] | 0.064† |
| ≤37 U/mL, n (%) | 204 (94) | 72 (97) | 34 (94) | 0.543‡ | 70 (74) | 104 (83) | 78 (84) | 0.131* |
| >37 U/mL, n (%) | 13 (6) | 2 (3) | 2 (6) | 25 (26) | 21 (17) | 15 (16) | ||
| Histologic differentiation, n (%) | ||||||||
| WD/MD | 224 (90) | 69 (86) | 36 (90) | 0.639* | 74 (70) | 97 (76) | 73 (72) | 0.554* |
| PD | 25 (10) | 11 (14) | 4 (10) | 31 (30) | 30 (24) | 29 (28) | ||
| Resection margin, n (%) | ||||||||
| Negative | 249 (99) | 72 (95) | 38 (93) | 0.025‡ | 97 (88) | 118 (90) | 96 (92) | 0.599* |
| Positive | 3 (1) | 4 (5) | 3 (7) | 13 (12) | 13 (10) | 8 (8) | ||
| LVSI, n (%) | ||||||||
| No | 187 (79) | 58 (82) | 27 (67) | 0.196* | 38 (36) | 51 (40) | 51 (50) | 0.122* |
| Yes | 50 (21) | 13 (18) | 13 (33) | 68 (64) | 76 (60) | 52 (50) | ||
| PNI, n (%) | ||||||||
| No | 193 (88) | 43 (80) | 31 (82) | 0.199* | 55 (54) | 50 (43) | 49 (49) | 0.280* |
| Yes | 26 (12) | 11 (20) | 7 (18) | 47 (46) | 66 (57) | 52 (51) | ||
| Extent of surgical resection, n (%) | ||||||||
| Non-radical | 60 (23) | 14 (17) | 5 (12) | 0.175* | 20 (18) | 7 (5) | 6 (6) | 0.001* |
| Radical | 198 (77) | 68 (83) | 36 (88) | 94 (82) | 126 (95) | 99 (94) | ||
No-AT, no adjuvant therapy; CTx, chemotherapy; CRT, chemoradiotherapy; Preop, preoperative; Postop, postoperative; CA 19-9, carbohydrate antigen 19-9; WD, well differentiation; MD, moderate differentiation; PD, poor differentiation; LVSI, lymphovascular space invasion; PNI, perineural invasion; Non-radical, cholecystectomy ± lymph node dissection; Radical, radical cholecystectomy and lymph node dissection. *Pearson’s chi-square test. †One-way analysis of variance. ‡Fisher’s exact test.