Table 2.
Demographics and clinical characteristics of included patients
| Characteristic | The Pooled (n=219) |
SEG I (n=55) |
SEG II (n=123) |
SEG III (n=32) |
SEG IV (n=4) |
SEG V (n=5) |
|---|---|---|---|---|---|---|
| Age, years | 54.4±12.4 | 52.7±13.1 | 55.4±12.2 | 54.8±12.7 | 50.3±11.8 | 50.4±11.0 |
| Gender*, male (%) | 156 (71.2) | 46 (83.6) | 85 (69.1) | 20 (62.5) | 3 (75.0) | 2 (40.0) |
| BMI, kg/m2 | 21.9±3.0 | 22.2±2.9 | 22.0±3.0 | 22.1±2.9 | 21.3±1.9 | 18.5±2.8 |
| NAT, n (%) | ||||||
| Chemoradiation | 176 (80.4) | 42 (76.4) | 102 (82.9) | 32 (100) | 0 | 0 |
| Radiation alone | 29 (13.2) | 11 (20.0) | 18 (14.6) | 0 | 0 | 0 |
| Chemotherapy alone | 14 (6.4) | 2 (3.6) | 3 (2.4) | 0 | 4 (100) | 5 (100) |
| Histology, n (%) | ||||||
| AC | 216 (98.6) | 52 (94.5) | 123 (100) | 32 (100) | 4 (100) | 5 (100) |
| SCC | 3 (1.4) | 3 (5.5) | 0 | 0 | 0 | 0 |
| Tumor location*, cm | 5.1±2.4 | 2.5±0.6 | 5.1±0.8 | 7.4±0.6 | 10.5±1.0 | 14.8±0.8 |
| Tumor thickness, mm | 11.3±7.3 | 11.4±6.7 | 11.4±7.8 | 11.5±6.9 | 11.3±3.2 | 8.5±5.0 |
| CEA level*, ng/ml | 14.5±34.0 | 12.2±26.5 | 15.1±37.7 | 11.1±24.0 | 24.9±34.0 | 69.2±93.8 |
| Surgical procedures*, n (%) | ||||||
| Miles' | 102 (46.6) | 47 (85.4) | 48 (39.0) | 5 (15.6) | 2 (50.0) | 0 |
| Dixon's | 112 (51.1) | 6 (10.9) | 73 (59.3) | 26 (81.3) | 2 (50.0) | 5 (100) |
| Hartmann's | 5 (2.3) | 2 (3.6) | 2 (1.7) | 1 (3.1) | 0 | 0 |
| Pathological TNM, n (%) | ||||||
| 0 | 53 (24.2) | 12 (21.8) | 31 (25.2) | 9 (28.1) | 0 | 1 (20.0) |
| I | 41 (18.7) | 13 (23.6) | 23 (18.7) | 4 (12.5) | 1 (25.0) | 0 |
| II | 72 (32.9) | 16 (29.1) | 41 (33.3) | 10 (31.3) | 3 (75.0) | 2 (40.0) |
| III | 53 (24.2) | 14 (25.5) | 28 (22.8) | 9 (28.1) | 0 | 2 (40.0) |
| Adjuvant therapy, n (%) | ||||||
| Chemoradiotherapy | 5 (2.3) | 2 (3.6) | 2 (1.7) | 1 (3.1) | 0 | 0 |
| Chemotherapy | 214 (97.7) | 53 (96.4) | 121 (98.3) | 31 (96.9) | 4 (100) | 5 (100) |
Values present with mean±SD or count (column percentage). The χ2 and Kruskal-wallis tests were used to compare differences among patient groups for nominal and continuous variables, respectively. SEG I-V stand for five groups according to tumor location. Comparisons were performed among SEG I, II and III, without SEG IV or V included. Abbreviations: SEG, rectal segment; BMI, body mass index; NAT, neoadjuvant therapy; AC, adenocarcinoma; SCC, squamous cell carcinoma; CEA, carcinoembryonic antigen. * indicates statistical difference among SEG I, II and III groups.