Table 3.
Characteristics of surgeries and response to neoadjuvant treatment in the SCRT and LCRT groups
| Short-course | Long-course | p-value | |
|---|---|---|---|
| Interval between start of RT and surgery (wk) | 11 ± 3.9 (6-28) | 18 ± 6.6 (11-39) | <0.001 |
| Interval between end of RT and surgery (wk) | 10 ± 3.9 (6-28) | 12 ± 6.6 (6-34) | 0.004 |
| Surgery center (n = 52) | 0.19 | ||
| Surgical oncology ward | 19 (73.1) | 15 (57.7) | |
| Colorectal surgery ward | 7 (26.9) | 11 (42.3) | |
| Surgical technique | 0.33 | ||
| Open LAR or VLAR | 28 (90.3) | 23 (88.5) | |
| APR | 0 | 1 (3.8) | |
| Laparoscopic LAR | 1 (3.2) | 2 (7.7) | |
| Total proctocolectomy | 2 (6.5) | 0 (0) | |
| Sphincter preservation | 31 (100) | 25 (96.2) | 0.50 |
| Surgical stage | 0.99 | ||
| 0 | 9 (29) | 7 (26.9) | |
| I | 8 (25.8) | 7 (26.9) | |
| II | 10 (32.3) | 9 (34.6) | |
| III | 4 (12.9) | 3 (11.5) | |
| Surgical N stage (ypN) | 0.46 | ||
| 0 | 27 (87.1) | 23 (88.5) | |
| 1 | 4 (12.9) | 2 (7.7) | |
| 2 | 0 (0) | 1 (3.8) | |
| Resected nodes | 8 ± 6.1 (0-23) | 9 ± 9.1 (0-39) | 0.55 |
| Positive lymph node ratio | 0.02 ± 0.06 (0-0.25) | 0.04 ± 0.15 (0-0.71) | 0.47 |
| Surgical T stage (ypT) | 0.46 | ||
| 0 | 10 (32.3) | 7 (26.9) | |
| 1 | 2 (6.5) | 1 (3.8) | |
| 2 | 6 (19.4) | 6 (23.1) | |
| 3 | 10 (32.3) | 12 (46.2) | |
| 4a | 3 (9.7) | 0 (0) | |
| Residual tumor size (cm) (n = 25) | 2.5±2.48 (1-11) | 2.3±0.9 (1-4.5) | 0.27 |
| R0 resection (No +ve/close margin ) | 31 (100) | 25 (96.2) | 0.46 |
| Tumor regression grade | 0.29 | ||
| 0 | 10 (32.3) | 6 (23.1) | |
| 1 | 3 (9.7) | 5 (19.2) | |
| 2 | 16 (51.6) | 10 (38.5) | |
| 3 | 2 (6.5) | 5 (19.2) | |
| Perineural invasion (n = 52) | 4 (14.3) | 2 (8.3) | 0.41 |
| Lymphovascular invasion (n = 52) | 4 (14.3) | 8 (33.3) | 0.10 |
| Down staging | 25 (80.6) | 22 (84.6) | 0.49 |
| Tumor down staging (ypT0-2) | 18 (58.1) | 14 (53.8) | 0.48 |
| Nodal down staging (ypN0) | 27 (87.1) | 23 (88.5) | 0.60 |
Values are presented as median ± standard deviation (range) or number (%).
SCRT, short-course chemoradiotherapy; LCRT, long-course chemoradiotherapy; LAR, low anterior resection; VLAR, very low anterior resection; APR, abdominal perineal resection.