Characteristic | No adjuvant chemotherapy Number (%) or mean [sd] n = 130 | Adjuvant chemotherapy Number (%) or mean [sd] n = 208 | Chi-squared P or F test P |
---|---|---|---|
Male sex | 78 (60.0) | 135 (64.9) | 0.364 |
Mean age (years) | 71.8 [12.7] | 59.8 [10.4] | <0.001 |
Age ≥ 75 years | 62 (47.7) | 9 (4.3) | <0.001 |
Preoperative radiotherapy | 20 (15.4) | 60 (28.9) | 0.005 |
Resection at urgent operation | 2 (1.5) | 3 (1.4) | 0.943 |
ASA physical status: | |||
 I healthy patient | 22 (16.9) | 60 (28.9) | <0.001 |
 II mild systemic disease | 67 (51.5) | 125 (60.1) | |
 III/IV severe systemic disease, severe systemic disease, a threat to life | 41 (31.5) | 23 (11.1) | |
Tumour site: | |||
 1 to 5 cm from anal verge | 31 (23.9) | 47 (22.6) | 0.329 |
 6 to 10 cm | 68 (52.3) | 96 (46.2) | |
 11 to 15 cm | 31 (23.9) | 65 (31.3) | |
Surgical access: | |||
 Open | 109 (83.9) | 149 (71.6) | 0.010 |
 Laparoscopic or laparoscopic-assisted | 21 (16.2) | 59 (28.4) | |
Operation type | |||
 Sphincter-preserving (anterior resection, Hartmann’s resection) | 101 (77.7) | 164 (78.9) | 0.802 |
 Non-sphincter preserving (abdominoperineal excision of rectum [APER]) | 29 (22.3) | 44 (21.2) | |
Mean tumour maximum surface dimension (cm) | 4.5 [1.8] | 4.0 [1.6] | 0.010 |
Tumour maximum surface dimension ≥ 4.5 cm | 66 (50.8) | 80 (38.8) | 0.032 |
Histological type: | |||
 Adenocarcinoma | 120 (92.3) | 193 (92.8) | 0.288 |
 Mucinous | 7 (5.4) | 14 (6.7) | |
 Signet ring | 3 (2.3) | 1 (0.5) | |
Direct spread | |||
 Submucosa | 8 (6.2) | 9 (4.3) | 0.595 |
 Muscularis propria | 19 (14.6) | 40 (19.2) | |
 Beyond muscularis propria | 89 (68.5) | 141 (67.8) | |
 To serosa | 14 (10.8) | 18 (8.7) | |
Mean number of lymph nodes examined | 16 [7.9] | 18 [7.8] | 0.037 |
≥ 12 nodes examined | 96 (73.9) | 167 (80.3) | 0.166 |
≥ 20% of nodes involved tumour | 49 (37.7) | 90 (43.3) | 0.311 |
Lymph node metastasis | |||
 Local only | 125 (96.2) | 196 (94.2) | 0.431 |
 Local and apical | 5 (3.9) | 12 (5.8) | |
 Apical only | 0 | 0 | |
Differentiation | |||
 Well/moderate | 100 (76.9) | 163 (78.4) | 0.756 |
 Poor | 30 (23.1) | 45 (21.6) | |
Lymphovascular invasion | |||
 Absent | 73 (56.2) | 117 (56.3) | 0.986 |
 Present | 57 (43.9) | 91 (43.8) | |
Perineural invasion | |||
 Absent | 101 (77.7) | 145 (69.7) | 0.109 |
 Present | 29 (22.3) | 63 (30.3) | |
Tumour perforation | |||
 Absent | 129 (99.2) | 199 (95.7) | 0.06 |
 Present | 1 (0.8) | 9 (4.3) | |
Tumour position | |||
 Anterior (including circumferential) | 69 (53.1) | 94 (45.2) | 0.158 |
 Other | 61 (46.9) | 114 (54.8) | |
Adjacent structures taken en bloc | |||
 No | 114 (87.7) | 188 (90.4) | 0.435 |
 Yes | 16 (12.3) | 20 (9.6) |