Table 2.
Univariate analyses for overall survival (OS) and progression-free survival (PFS)
| Univariate for OS | Univariate for PFS | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Variable | Category | No (%) | No of event (%) | median | 95% CI | p | No of event (%) | median | 95% CI | p | |
| Overall | 55 (100) | 42 (76.4) | 24.2 | 14.0-34.4 | 54 (98.2) | 8.7 | 6.1-11.3 | ||||
| Age | ≤60 | 28 (50.9) | 19 (67.9) | 26.2 | 17.8-34.6 | 0.13 | 27 (96.4) | 9.1 | 6.4-11.8 | 0.34 | |
| > 60 | 27 (49.1) | 23 (85.2) | 19.8 | 4.4-35.2 | 27 (100) | 7.5 | 5.5-9.5 | ||||
| Gender | male | 34 (61.8)) | 25 (73.5) | 25.1 | 16.9-33.3 | 0.6 | 33 (97.1) | 8.7 | 5.7-11.7 | 0.46 | |
| female | 21 (38.2) | 17 (81.0) | 19.8 | 8.6-30.9 | 21 (100) | 7.5 | 4.7-10.3 | ||||
| Primary site | colon | 42 (76.4) | 29 (69.0) | 26.2 | 19.8-32.6 | 0.047 | 41 (97.6) | 8.2 | 5.6-10.8 | 0.49 | |
| rectum | 13 (33.6) | 13 (100) | 15.7 | 10.1-21.3 | 13 (100) | 9.7 | 2.3-17.1 | ||||
| AJCC stage, 7th | IVa | 21 (38.2) | 14 (66.7) | 34.6 | 22.6-46.4 | 0.026 | 20 (95.2) | 12.9 | 6.8-19.0 | 0.17 | |
| IVb | 34 (61.8) | 28 (82.4) | 15.7 | 11.4-20.0 | 34 (100) | 7.8 | 6.8-8.8 | ||||
| Grade | well or moderately | 41 (74.5) | 31 (75.6) | 26.3 | 20.3-32.3 | 0.008 | 40 (97.6) | 9.1 | 6.5-11.7 | 0.69 | |
| poorly | 14 (25.5) | 11 (78.6) | 12.5 | 4.2-20.8 | 14 (100) | 7.5 | 6.6-8.4 | ||||
| Previous history of colectomy | yes | 23 (41.8) | 12 (52.2) | 43.9 | 12.9-74.9 | <0.001 | 22 (95.7) | 12.8 | 7.9-17.7 | 0.022 | |
| no | 32 (58.2) | 30 (93.8) | 15.7 | 9.6-21.8 | 32 (100) | 7.2 | 4.9-9.5 | ||||
| KRAS mutation |
mutant | 17 (30.9) | 14 (82.4) | 17.4 | 7.0-27.8 | 0.27 | 17 (100) | 7.2 | 1.7-12.7 | 0.63 | |
| no mutant | 38 (69.1) | 28 (73.7) | 27.7 | 18.9-36.6 | 37 (97.4) | 9.7 | 6.8-12.6 | ||||
| Chemotherapy regimen | Oxaliplatin-based | 17 (30.9) | 13 (76.5) | 15.7 | 8.6-22.8 | 0.48 | 17 (100) | 5.4 | 0.0-9.8 | 0.14 | |
| Irinotecan-based | 38 (69.1) | 29 (76.3) | 26.3 | 17.6-34.9 | 37 (97.4) | 10.6 | 8.3-12.9 | ||||
| ECOG performance | 0~1 | 36 (65.5) | 24 (66.7) | 31.8 | 21.0-42.6 | <0.001 | 35 (97.2) | 11.5 | 8.0-15.0 | <0.001 | |
| 2~4 | 19 (45.5) | 18 (94.7) | 10.8 | 1.7-19.9 | 19 (100) | 3.8 | 2.1-5.5 | ||||
| CEA level, ng/dL | ≤5 | 18 (32.7) | 13 (72.2) | 25.1 | 14.0-36.2 | 0.92 | 17 (94.4) | 7.4 | 2.0-12.8 | 0.57 | |
| >5 | 37 (67.3) | 29 (78.4) | 21.6 | 9.2-34.0 | 37 (100) | 10 | 6.7-13.3 | ||||
| CTC, numbers/ mL |
≤30 | 26 (47.3) | 17 (65.4) | 37.1 | 22.5-51.6 | 0.005 | 25 (96.2)) | 13.3 | 11.7-14.9 | <0.001 | |
| >30 | 29 (52.7) | 25 (86.2) | 14.9 | 8.9-21.2 | 29 (100) | 5.1 | 3.5-6.7 | ||||
AJCC: American Joint Committee on Cancer; ECOG: Eastern Cooperative Oncology Group
CEA: carcinoembryonic antigen; CTC: circulating tumour cell