Table 1 Patient demographics and tumor characteristics
Variable | Total (n = 323) | pCR (n = 75) | Non-pCR (n = 248) | P value |
|---|---|---|---|---|
Age (years)a | 57 (26–86) | 57 (26–86) | 58 (32–78) | 0.773 |
Sex | 0.342 | |||
 Male | 174 (53.9) | 44 (58.7) | 130 (52.4) | |
 Female | 149 (46.1) | 31 (41.3) | 118 (47.6) | |
BMI (kg/m2)a | 23.6 (17.0–32.2) | 24.2 (17.4–31.2) | 23.5 (17.0–32.2) | 0.386 |
cT category | 0.297 | |||
 2 | 26 (8.0) | 7 (9.3) | 19 (7.6) | |
 3 | 234 (72.5) | 58 (77.3) | 176 (71.0) | |
 4 | 63 (19.5) | 10 (13.3) | 53 (21.4) | |
cN category | 0.791 | |||
 N0 | 88 (27.2) | 21 (28.0) | 67 (27.0) | |
 N1 | 161 (49.9) | 35 (46.7) | 126 (50.8) | |
 N2 | 74 (22.9) | 19 (25.3) | 55 (22.2) | |
cTNM classification | 0.867 | |||
 II | 88 (27.2) | 21 (28.0) | 67 (27.0) | |
 III | 235 (72.8) | 54 (72.0) | 181 (73.0) | |
Distance from the anal verge (cm)a | 6 (0–10) | 6 (0–10) | 6 (0–10) | 0.721 |
Pretreatment CEA (ng/mL)a | 3.8 (0.02–31.5) | 2.9 (0.06–24.9) | 4.2 (0.02–31.5) | 0.001 |
Tumor differentiation | 0.679 | |||
 Well | 24 (7.4) | 6 (8.0) | 18 (7.3) | |
 Moderate | 250 (77.4) | 60 (80.0) | 190 (76.6) | |
 Poor | 49 (15.2) | 9 (12.0) | 40 (16.1) | |
Type of surgery | 0.543 | |||
 Low anterior resection | 190 (58.8) | 40 (53.3) | 150 (60.5) | |
 Abdominoperineal resection | 122 (37.8) | 32 (42.7) | 90 (36.3) | |
 Hartmann operation | 11 (3.4) | 3 (4.0) | 8 (3.2) | |
Chemotherapy | 0.729 | |||
 Capecitabine | 267 (82.7) | 61 (81.3) | 206 (83.1) | |
 Capecitabine + oxaliplatin | 56 (17.3) | 14 (18.7) | 42 (16.9) | |
Time interval (day)a | 50 (25–105) | 57 (35–79) | 49 (25–105) | <0.001 |
Radiation dose (Gy)a | 50 (38–60) | 50 (40–60) | 50 (38–60) | 0.225 |