TABLE 1.
Baseline characteristics of patients with cT3–4M0 rectal cancer located ≤8 cm from the anorectal junction based on MRI re-review (n = 1109) of those who received neoadjuvant radiotherapy (n = 891) and those who did not (n = 218)
| Variable | n = 891 (%) | n = 218 (%) |
|---|---|---|
| Sex: male | 581 (65.2) | 157 (72.0) |
| Age, y, mean (SD) | 72.1 (10.6) | 74.9 (11.3) |
| Distance of tumor from anorectal junction, cm, mean (SD) | 3.3 (2.5) | 4.1 (2.3) |
| Tumor according to LOREC criteria On/below Above |
541 (60.7) 350 (39.3) |
104 (47.7) 114 (52.3) |
| Clinical T stage T3a (<1 mm beyond muscularis propria) T3b (1–4.9 mm beyond muscularis propria) T3c (5–15 mm beyond muscularis propria) T3d (>15 mm beyond muscularis propria) T4a (invasion of peritoneum) T4b (invasion surrounding organs/structures) |
174 (19.5) 287 (32.2) 221 (24.8) 56 (6.3) 53 (6.0) 100 (11.2) |
87 (39.9) 91 (41.7) 30 (13.8) 2 (0.9) 7 (3.2) 1 (0.5) |
| Threatened MRF or T4 on primary MRI (tumor ≤1 mm of the MRF) | 439 (49.3) | 32 (14.7) |
| Mesorectal clinical N stage N0 N1 N2 |
183 (20.5) 400 (44.9) 308 (34.6) |
167 (76.6) 46 (21.1) 5 (2.3) |
| mrEMVI | 314 (35.2) | 32 (14.7) |
| Tumor deposits on primary MRI | 143 (16.0) | 4 (1.8) |
| All LLNs visible on primary MRI Largest LLN in obturator compartment Largest LLN in internal iliac compartment Patients with LLNs only in external iliac compartment Patients with only stretched-out “benign” obturator LLNs |
314/891 (35.2) 226/314 (72.0) 58/314 (18.5) 17/314 (5.4) 13/314 (4.1) |
58/218 (26.6) 40/58 (69.0) 8/58 (13.8) 10/58 (17.2) – |
| LLN characteristics One or more internal iliac/obturator LLN with SA ≥7 mm Any LLN with at least 1 malignant feature |
122 (13.7) 157 (17.6) |
6 (2.8) 18 (8.3) |
| Neoadjuvant treatment None Short-course radiotherapy Chemoradiotherapy Chemotherapy alone |
– 338 (37.9) 553 (62.1) – |
216 (99.1) ––2 (0.9) |
| Resection of primary tumor Local excisiona Local excision followed by TME Low anterior resection/TME Abdominoperineal resection Hartmann procedure Proctocolectomy Total exenteration |
5 (0.6) – 411 (46.1) 338 (37.9) 134 (15.0) 2 (0.2) 1 (0.1) |
7 (0.5) 2 (0.2) 123 (56.9) 49 (22.7) 34 (15.7) 1 (0.1) – |
| Underwent some form of additional surgery for LLN Yes No |
33 (3.7) 858 (96.3) |
– – |
| Resection margins (%) R0 R1 |
823 (92.4) 68 (7.6) |
206 (94.5) 12 (5.5) |
Data presented as n (%) or n/N (%) unless otherwise noted.
LLN = lateral lymph node; LOREC = low rectal cancer development program—lower border of the tumor is located beneath the attachment of the levator ani (seen on coronal plane); mrEMVI = MRI-identified extramural venous invasion; MRF = mesorectal fascia; PME = partial mesorectal excision; SA = short axis; TME = total mesorectal excision.
a
Tumors were initially staged higher according to clinical staging but were later confirmed lower by pathology.