Table 2.
Surgical and pathological outcomes of patients with low rectal cancer
| Characteristics | Underweight (n = 53) | Normal weight (n = 589) | Overweight (n = 336) | Obesity (n = 61) | P value |
|---|---|---|---|---|---|
| Surgical characteristics | |||||
| Surgical approach, No. (%) | 0.897 | ||||
| Open | 14 (26.4) | 185 (28.8) | 103 (30.7) | 19 (31.1) | |
| Laparoscopic | 39 (73.6) | 457 (71.2) | 233 (69.3) | 42 (68.9) | |
| Conversion to open surgery, No. (%) a | 2 (3.8) | 12 (1.9) | 3 (0.9) | 2 (3.3) | 0.162 |
| Type of surgery, No. (%) | 0.004 | ||||
| Low anterior resection | 40 (76.9) | 359 (61.4) | 206 (61.5) | 26 (43.3) | |
| Intersphincteric resection | 4 (7.7) | 47 (8.0) | 30 (9.0) | 3 (5.0) | |
| Abdominoperineal resection | 8 (15.4) | 179 (30.6) | 99 (29.6) | 31 (51.7) | |
| Anal sphincter preservation b | 45 (84.9) | 409 (69.4) | 237 (70.5) | 30 (49.2) | < 0.001 |
| Diverting ostomy, No. (%) c | 38 (84.4) | 314 (76.8) | 181 (76.4) | 22 (73.3) | 0.637 |
| Type of diverting ostomy, No. (%) | 0.808 | ||||
| Ileostomy | 38 (100) | 303 (96.5) | 170 (93.9) | 21 (95.5) | 0.298 |
| Colostomy | 0 | 11 (3.5) | 11 (6.1) | 1 (4.5) | |
| Combined multivisceral resection, No. (%) | 3 (5.7) | 15 (2.5) | 5 (1.5) | 1 (1.6) | 0.222 |
| Operative time (min), median(IQR) | 150 (120, 196) | 180 (145, 225) | 191 (165, 244.5) | 217.5 (183.5, 252.5) | < 0.001 |
| Estimated blood loss (ml), median (IQR) | 50 (20, 100) | 50 (50, 100) | 50 (40, 100) | 100(50, 100) | 0.001 |
| Intraoperative complications, No. (%) | 0 | 5 (0.8) | 12 (3.6) | 2 (3.3) | 0.014 |
| Pathological outcomes | |||||
| pT stage, No. (%) | 0.10 | ||||
| 0/Tis | 7 (13.2) | 77 (13.1) | 49 (14.6) | 7 (11.5) | |
| 1 | 6 (11.3) | 51 (8.7) | 40 (11.9) | 3 (4.9) | |
| 2 | 20 (37.7) | 205 (34.8) | 125 (37.2) | 24 (39.3) | |
| 3 | 11 (20.8) | 229 (38.9) | 103 (30.7) | 24 (39.3) | |
| 4 | 9 (17.0) | 27 (4.6) | 19 (5.7) | 3 (4.9) | |
| pN stage, No. (%) | 0.672 | ||||
| 0 | 36 (67.9) | 436 (74.0) | 261 (77.7) | 44 (72.1) | |
| 1 | 12 (22.6) | 117 (19.9) | 58 (17.3) | 14 (23.0) | |
| 2 | 5 (9.4) | 36 (6.1) | 17 (5.1) | 3 (4.9) | |
| pTNM stage, No. (%) | 0.725 | ||||
| 0/pCR | 7 (13.2) | 73 (12.4) | 47 (14.0) | 7 (11.5) | |
| I | 20 (37.7) | 208 (35.3) | 133 (39.6) | 23 (37.7) | |
| II | 9 (17.0) | 154 (26.1) | 82 (24.4) | 14 (23.0) | |
| III | 17 (32.1) | 154 (26.1) | 74 (22.0) | 17 (27.9) | |
| No. of retrieved lymph nodes, median (IQR) | 14 (11, 20) | 13 (9, 17) | 12 (9, 16) | 12 (7, 14) | 0.027 |
| Histopathology, No. (%) | 0.314 | ||||
| Adenocarcinoma | 52 (98.1) | 557 (94.6) | 310 (92.3) | 57 (93.4) | |
| Mucinous adenocarcinoma/Signet-ring cell carcinoma | 1 (1.9) | 32 (5.4) | 26 (7.7) | 4 (6.6) | |
| Tumor differentiation, No. (%) | 0.551 | ||||
| Well differentiated | 2 (3.8) | 46 (7.8) | 28 (8.3) | 7 (11.5) | |
| Moderately differentiated | 36 (67.9) | 327 (55.5) | 191 (56.8) | 38 (62.3) | |
| Poorly differentiated | 4 (7.5) | 41 (7.0) | 18 (5.4) | 3 (4.9) | |
| Undifferentiated | 0 | 3 (0.5) | 1 (0.3) | 1 (1.6) | |
| Unknown | 11 (20.8) | 172 (29.2) | 98 (29.2) | 12 (19.7) | |
| TME quality, No. (%) d | 0.015 | ||||
| Complete | 44 (88.0) | 443 (85.7) | 259 (85.8) | 41 (78.8) | |
| Nearly complete | 5 (10.0) | 63 (12.2) | 35 (11.6) | 5 (9.6) | |
| Incomplete | 1 (2.0) | 11 (2.1) | 8 (2.6) | 6 (11.5) | |
| Length of PRM (mm), median (IQR) |
116 (80,150) |
125 (95, 150) |
125 (95, 150) |
125 (95, 150) |
0.126 |
| Length of DRM (mm), median (IQR) | 22 (15, 35) | 20 (13, 30) | 20 (13, 30) | 20 (13, 30) | 0.579 |
| Negative DRM, No. (%) | 53 (100) | 588 (99.8) | 333 (99.1) | 61 (100) | 0.332 |
| Negative CRM, No. (%) | 52 (98.1) | 632 (98.4) | 333 (99.1) | 61 (100) | 0.305 |
Tis, Carcinoma in situ; pCR, pathological complete response; IQR, interquartile range; PRM, proximal resection margin; DRM, distal resection margin; CRM, circumferential resection margin; TME, total mesorectal excision; NA, not applicable.
a Data were obtained from 1032 patients. In the Underweight group, 1 patient underwent underwent transanal total mesorectal excision. In the Normal weight group, 2 patients underwent the Hartmann procedure, 1 underwent total proctocolectomy, and 1 underwent posterior pelvic resection. In the Overweight group, 1 patient underwent transanal total mesorectal excision. In the Obesity group, 1 patient underwent the Hartmann procedure.
b In the Underweight group, 40 patients underwent low anterior resection, 4 underwent intersphincteric resection, and 1 underwent transanal total mesorectal excision. In the Normal weight group, 359 patients underwent low anterior resection, 37 underwent intersphincteric resection, 2 underwent the Hartmann procedure, and 1 underwent posterior pelvic resection. In the Overweight group, 206 patients underwent low anterior resection, 30 underwent intersphincteric resection, and 1 underwent transanal total mesorectal excision. In the Obesity group, 26 patients underwent low anterior resection, 3 underwent intersphincteric resection, and 1 underwent the Hartmann procedure.
c Only patients who underwent sphincter-preserving surgery were included.
d Data were obtained from 921 patients.