Table 1.
Patient characteristics
| 6M group (n = 642) | 12M group (n = 636) | |||
|---|---|---|---|---|
| n | (%) | n | (%) | |
| Age | ||||
| Median [range] | 65 [23–79] | 65 [34–79] | ||
| Gender | ||||
| Male | 347 | (54.0%) | 339 | (53.3%) |
| Female | 295 | (46.0%) | 297 | (46.7%) |
| ECOG performance status | ||||
| 0 | 611 | (95.2%) | 617 | (97.0%) |
| 1 | 31 | (4.8%) | 19 | (3.0%) |
| Creatinine clearance (mL/min) | ||||
| Median [range] | 76.6 [35.1–350.4] | 78.1 [39.2–176.3] | ||
| Body surface area (m2) | ||||
| Median [range] | 1.59 [1.06–2.42] | 1.56 [1.10–2.14] | ||
| <1.33 (dose 3000 mg/body/day) | 41 | (6.4%) | 48 | (7.5%) |
| ≥1.33 to <1.57 (dose 3600 mg/body/day) | 262 | (40.8%) | 272 | (42.8%) |
| ≥1.57 to <1.81 (dose 4200 mg/body/day) | 274 | (42.7%) | 261 | (41.0%) |
| ≥1.81 (dose 4800 mg/body/day) | 65 | (10.1%) | 55 | (8.6%) |
| Tumor location | ||||
| Right-sided colon (C, A, T) | 261 | (40.6%) | 258 | (40.6%) |
| Left-sided colon (D, S) | 247 | (38.5%) | 247 | (38.8%) |
| Rectosigmoid colon | 134 | (20.9%) | 131 | (20.6%) |
| Depth of tumor invasion (TNM 7th) | ||||
| T1 | 44 | (6.9%) | 45 | (7.1%) |
| T2 | 54 | (8.4%) | 52 | (8.2%) |
| T3 | 360 | (56.1%) | 355 | (55.8%) |
| T4 | 184 | (28.7%) | 184 | (28.9%) |
| LN metastasis (JSCCR classificationa) | ||||
| N1 | 491 | (76.5%) | 486 | (76.4%) |
| N2 | 120 | (18.7%) | 121 | (19.0%) |
| N3 | 31 | (4.8%) | 29 | (4.6%) |
| Stage (TNM 7th) | ||||
| IIIA | 91 | (14.2%) | 93 | (14.6%) |
| IIIB | 455 | (70.9%) | 450 | (70.8%) |
| IIIC | 96 | (15.0%) | 93 | (14.6%) |
| Scope of LN dissection (JSCCR classificationa) | ||||
| D2 | 129 | (20.1%) | 133 | (20.9%) |
| D3 | 513 | (79.9%) | 503 | (79.1%) |
| Surgical approach | ||||
| Open (conventional) | 371 | (57.8%) | 388 | (61.0%) |
| Laparoscopic | 271 | (42.2%) | 248 | (39.0%) |
ECOG Eastern Cooperative Oncology Group, C cecum, A ascending colon, T transverse colon, D descending colon, S sigmoid colon, LN lymph node
N1: Metastasis in 1–3 pericolic/perirectal LNs or intermediate LNs (LNs along the colic artery)
N2: Metastasis in ≥4 pericolic/perirectal or intermediate LNs
N3: Metastasis in LNs around the origin of the ileocolic, right colic, middle colic, or inferior mesenteric artery
D2: Complete dissection of pericolic/perirectal and intermediate LNs
D3: Complete dissection of all regional LNs
aDefined in the Japanese Classification of Colorectal Carcinoma 8th edition, published by the Japanese Society for Cancer of the Colon and Rectum (JSCCR) [10]