TABLE 1.
Clinical and pathological characteristics of pancreatic cancer cases, overall or by KRAS mutation status
| Characteristic a | All cases | KRAS mutation | p value | KRAS‐mutant tumors (n = 1139) | p value | |||
|---|---|---|---|---|---|---|---|---|
| KRAS VAF | ||||||||
| Wild type | Mutant | 1%–9% | 10%–19% | ≥20% | ||||
| (n = 1162) | (n = 23) | (n = 1139) | (n = 276) | (n = 503) | (n = 360) | |||
| Mean age ± SD (years) | 67.2 ± 9.7 | 66.0 ± 13.7 | 67.2 ± 9.6 | 0.55 | 67.1 ± 8.9 | 67.3 ± 9.4 | 67.0 ± 10.4 | 0.91 |
| Sex | 0.52 | 0.41 | ||||||
| Female | 480 (41) | 8 (35) | 472 (41) | 108 (39) | 205 (41) | 159 (44) | ||
| Male | 682 (59) | 15 (65) | 667 (59) | 168 (61) | 298 (59) | 201 (56) | ||
| Year of diagnosis | 0.23 | 0.037 | ||||||
| 2005–2010 | 337 (29) | 3 (13) | 334 (29) | 78 (28) | 160 (32) | 96 (27) | ||
| 2011–2014 | 393 (34) | 9 (39) | 384 (34) | 81 (29) | 162 (32) | 141 (39) | ||
| 2015–2017 | 432 (37) | 11 (48) | 421 (37) | 117 (43) | 181 (36) | 123 (34) | ||
| Tumor location | 0.31 | 0.43 | ||||||
| Head of the pancreas | 741 (64) | 17 (74) | 724 (64) | 184 (67) | 312 (62) | 228 (63) | ||
| Body to tail of the pancreas | 421 (36) | 6 (26) | 415 (36) | 92 (33) | 191 (38) | 132 (37) | ||
| Histological type | 0.001 | <0.001 | ||||||
| Adenocarcinoma | 1132 (97) | 20 (87) | 1112 (98) | 276 (100) | 494 (98) | 342 (95) | ||
| Adenosquamous carcinoma | 30 (2.6) | 3 (13) | 27 (2.4) | 0 | 9 (1.8) | 18 (5.0) | ||
| Tumor differentiation b | 0.21 | 0.20 | ||||||
| Well to moderate | 664 (59) | 9 (45) | 655 (59) | 169 (61) | 298 (60) | 188 (55) | ||
| Poor | 468 (41) | 11 (55) | 457 (41) | 107 (39) | 196 (40) | 154 (45) | ||
| Stroma type | 0.70 | 0.010 | ||||||
| Non‐scirrhous | 764 (66) | 16 (70) | 748 (66) | 166 (60) | 325 (65) | 257 (71) | ||
| Scirrhous | 398 (34) | 7 (30) | 391 (34) | 110 (40) | 178 (35) | 103 (29) | ||
| Lymphatic invasion | 0.58 | 0.013 | ||||||
| Absent/mild | 745 (64) | 16 (70) | 729 (64) | 189 (68) | 331 (66) | 209 (58) | ||
| Moderate/marked | 417 (36) | 7 (30) | 410 (36) | 87 (32) | 172 (34) | 151 (42) | ||
| Venous invasion | 0.38 | <0.001 | ||||||
| Absent/mild | 403 (35) | 6 (26) | 397 (35) | 128 (46) | 175 (35) | 94 (26) | ||
| Moderate/marked | 759 (65) | 17 (74) | 742 (65) | 148 (54) | 328 (65) | 266 (74) | ||
| Neural invasion | 0.20 | <0.001 | ||||||
| Absent/mild | 410 (35) | 11 (48) | 399 (35) | 123 (45) | 162 (32) | 114 (32) | ||
| Moderate/marked | 752 (65) | 12 (52) | 740 (65) | 153 (55) | 341 (68) | 246 (68) | ||
| Mean tumor size ± SD (cm) | 3.4 ± 1.6 | 3.6 ± 1.5 | 3.4 ± 1.6 | 0.64 | 3.2 ± 1.6 | 3.4 ± 1.5 | 3.7 ± 1.6 | <0.001 |
| Tumor cellularity | 0.20 | <0.001 | ||||||
| <30% | 505 (43) | 13 (57) | 492 (43) | 248 (90) | 210 (42) | 34 (9.4) | ||
| ≥30% | 657 (57) | 10 (43) | 647 (57) | 28 (10) | 293 (58) | 326 (91) | ||
| Cellularity of inflammatory cells | 0.41 | <0.001 | ||||||
| <25% | 111 (9.6) | 2 (8.7) | 109 (9.6) | 13 (4.7) | 35 (7.0) | 61 (17) | ||
| 25–49% | 738 (63) | 12 (52) | 726 (64) | 123 (45) | 338 (67) | 265 (74) | ||
| ≥50% | 313 (27) | 9 (39) | 304 (27) | 140 (51) | 130 (26) | 34 (9.4) | ||
| UICC cancer stage | 0.47 | 0.25 | ||||||
| I | 301 (26) | 8 (35) | 293 (26) | 80 (29) | 130 (26) | 83 (23) | ||
| II | 506 (44) | 11 (48) | 495 (43) | 117 (42) | 223 (44) | 155 (43) | ||
| III | 305 (26) | 4 (17) | 301 (26) | 68 (25) | 134 (27) | 99 (28) | ||
| IV | 50 (4.3) | 0 | 50 (4.4) | 11 (4.0) | 16 (3.2) | 23 (6.4) | ||
| Resection margin status | 0.80 | 0.78 | ||||||
| R0 | 899 (77) | 19 (83) | 880 (77) | 209 (76) | 397 (79) | 274 (76) | ||
| R1 | 257 (22) | 4 (17) | 253 (22) | 66 (24) | 103 (20) | 84 (23) | ||
| R2 | 6 (0.5) | 0 | 6 (0.5) | 1 (0.4) | 3 (0.6) | 2 (0.6) | ||
| Neoadjuvant therapy | 0.51 | <0.001 | ||||||
| None | 1013 (87) | 19 (83) | 994 (87) | 219 (79) | 442 (88) | 333 (93) | ||
| Chemotherapy c | 149 (13) | 4 (17) | 145 (13) | 57 (21) | 61 (12) | 27 (7.5) | ||
| Adjuvant therapy | 0.28 | 0.73 | ||||||
| None | 248 (21) | 7 (30) | 241 (21) | 61 (22) | 101 (20) | 79 (22) | ||
| Chemotherapy c | 914 (79) | 16 (70) | 898 (79) | 215 (78) | 402 (80) | 281 (78) | ||
Note: Data are shown as n (%) unless otherwise indicated.
Abbreviation: VAF, variant allele frequency.
a
Percentage indicates the proportion of cases with a specific clinical or pathological characteristic in all cases or in each stratum of KRAS mutation status. Total percentages may not equal 100% due to rounding.
b
Tumor differentiation was assessed only for adenocarcinomas.
c
These categories include chemoradiotherapy.