Table 1.
Clinical and pathological characteristics of patients and tumors by DNA mismatch repair (MMR) status
| Total No. of patients (n = 2141)* |
|||
| Proficient MMR (n = 1797) | Deficient MMR (n = 344) | ||
| Variable | No. (%) | No. (%) | P |
| Study group† | .317‡ | ||
| FFCD | 124 (80.5) | 30 (19.5) | |
| NCIC | 244 (85.0) | 43 (15.0) | |
| GIVIO | 153 (83.6) | 30 (16.4) | |
| NSABP | 438 (81.9) | 97 (18.1) | |
| NCCTG | 838 (85.3) | 144 (14.7) | |
| Sex | .019‡ | ||
| Women | 817 (81.9) | 180 (18.1) | |
| Men | 980 (85.7) | 164 (14.3) | |
| Colon cancer stage | <.001‡ | ||
| III | 1183 (86.8) | 180 (13.2) | |
| II | 614 (78.9) | 164 (21.1) | |
| Tumor histological grade§ | <.001‡ | ||
| Grade 1 or 2‖ | 1113 (88.8) | 141 (11.2) | |
| Grade 3 or 4‖ | 239 (69.9) | 103 (30.1) | |
| Primary tumor site§ | <.001‡ | ||
| Distal | 1059 (93.9) | 69 (6.1) | |
| Proximal | 712 (72.6) | 269 (27.4) | |
| Treatment status | .322‡ | ||
| Observation ¶ or no 5-FU | 629 (82.9) | 130 (17.1) | |
| 5-FU-based | 1168 (84.5) | 214 (15.5) | |
| Recurrence status | <.001‡ | ||
| No recurrence | 1222 (81.8) | 271 (18.2) | |
| Recurrence | 575 (88.7) | 73 (11.3) | |
| Site of recurrence§ | .171‡ | ||
| Intra-abdominal | 122 (84.7) | 22 (15.3) | |
| Local only | 41 (91.1) | 4 (8.9) | |
| Distant | 387 (90.2) | 42 (9.8) | |
| Age, y | .947# | ||
| Mean (SD) | 60.8 (10.38) | 60.1 (12.26) | |
| Median (range) | 62 (21.0–88.0) | 62.0 (22.0–86.2) | |
Patients with stage II (n = 778) and III (n = 1363) colon cancers who participated in clinical trials of 5-FU-based adjuvant therapy. FFCD = Federation Francophone de la Cancerologie Digestive; FU = fluorouracil; GIVIO = Gruppo Italiano Valutazione Interventi in Oncologia; NCCTG = North Central Cancer Treatment Group; NCIC = National Cancer Institute of Canada; NSABP = National Surgery Adjuvant Breast and Bowel Project; SD = standard deviation.
Randomized clinical trials evaluating 5-FU-based adjuvant chemotherapy.
P values were calculated using a two-sided χ2 test.
Missing observations.
Grade 1 or 2 = well or moderate differentiation; grade 3 or 4 = poor differentiation or undifferentiated.
Observation is defined as surgery alone.
P value was calculated using a two-sided Wilcoxon rank-sum test.