Table 1.
Clinical characteristics and treatments of patients by age at diagnosis
| Characteristic | Overall (n = 5,457) | Colorectal cancer | ||
| 18–44 yr (n = 253) | 44–80 yr (n = 5,204) | P valuea | ||
| Sex, n (%) | ||||
| Female | 2,281 (41.8) | 115 (45.5) | 2,166 (41.6) | 0.286 |
| Male | 3,176 (58.2) | 138 (54.5) | 3,038 (58.4) | |
| TNM stage at diagnosis, n (%) | ||||
| Stage I | 837 (15.3) | 31 (12.3) | 806 (15.5) | 0.286 |
| Stage II | 2,264 (41.5) | 102 (40.3) | 2,162 (41.5) | |
| Stage III | 2,019 (37.0) | 98 (38.7) | 1,921 (36.9) | |
| Stage IV | 337 (6.2) | 22 (8.7) | 315 (6.1) | |
| Location, n (%) | ||||
| Rectum | 3,005 (55.1) | 141 (55.7) | 2,864 (55.0) | 0.286 |
| Left colon | 1,289 (23.6) | 66 (26.1) | 1,223 (23.5) | |
| Right colon | 1,131 (20.7) | 43 (17.0) | 1,088 (20.9) | |
| Unspecified | 32 (0.6) | 3 (1.2) | 29 (0.6) | |
| Pathological grade, n (%) | ||||
| Well/moderately differentiated | 4,132 (75.7) | 171 (67.6) | 3,961 (76.1) | 0.009 |
| Poor differentiated | 755 (13.8) | 42 (16.6) | 713 (13.7) | |
| Special typesb | 454 (8.3) | 33 (13.0) | 421 (8.1) | |
| Unknown | 116 (2.1) | 7 (2.8) | 109 (2.1) | |
| Vascular invasion, n (%) | ||||
| No | 4,715 (86.4) | 205 (81.0) | 4,510 (86.7) | 0.025 |
| Yes | 742 (13.6) | 48 (19.0) | 694 (13.3) | |
| Perineural invasion, n (%) | ||||
| No | 4,944 (90.6) | 224 (88.5) | 4,720 (90.7) | 0.298 |
| Yes | 513 (9.4) | 29 (11.5) | 484 (9.3) | |
| MMR status, n (%) | ||||
| MMR deficient | 643 (11.8) | 57 (22.5) | 586 (11.3) | <0.001 |
| MMR proficient | 2,802 (51.3) | 115 (45.5) | 2,687 (51.6) | |
| Unknown | 2,012 (36.9) | 81 (32.0) | 1,931 (37.1) | |
| Postoperative chemotherapy, n (%) | ||||
| No | 2,244 (41.1) | 60 (23.7) | 2,184 (42.0) | <0.001 |
| Yes | 2,893 (53.0) | 171 (67.6) | 2,722 (52.3) | |
| Single agentc | 382 (7.0) | 10 (4.0) | 372 (7.1) | |
| Multiagent | 2,424 (44.4) | 155 (61.3) | 2,269 (43.6) | |
| FOLFOX | 1,671 (30.6) | 102 (40.3) | 1,569 (30.1) | |
| CAPEOX | 357 (6.5) | 29 (11.5) | 328 (6.3) | |
| FOLFIRI | 396 (7.3) | 24 (9.5) | 372 (7.1) | |
| Regimen unknown | 87 (1.6) | 6 (2.3) | 81 (1.5) | |
| Chemotherapy unknown | 320 (5.9) | 22 (8.7) | 298 (5.7) | |
| Postoperative radiotherapy, n (%) | ||||
| Yes | 374 (6.9) | 31 (12.3) | 343 (6.6) | <0.001 |
| No | 2,069 (37.9) | 78 (30.8) | 1,991 (38.3) | |
| Unknown | 3,014 (55.2) | 144 (56.9) | 2,870 (55.1) | |
MMR, mismatch repair; TNM, tumour, node, and metastasis.
a
P values were corrected using the Benjamini-Hochberg method.
b
Special types include mucinous adenocarcinoma, signet-ring cell carcinoma, and squamous cell carcinoma.
c
Single agent refers to capecitabine or 5-fluorouracil based.