Endoscopic resection of high-risk T1 colorectal carcinoma prior to surgical resection has no adverse effect on long-term outcomes.
It is difficult to predict the presence of histological risk factors for lymph node metastasis (LNM) before endoscopic treatment of T1 colorectal cancer (CRC). Therefore, endoscopic therapy is propagated to obtain adequate histological staging. We examined whether secondary surgery following endoscopic resection of high-risk T1 CRC does not have a negative effect on patients' outcomes compared with primary surgery.



Patients with T1 CRC with one or more histological risk factors for LNM (high risk) and treated with primary or secondary surgery between 2000 and 2014 in 13 hospitals were identified in the Netherlands Cancer Registry. Additional data were collected from hospital records, endoscopy, radiology and pathology reports. A propensity score analysis was performed using inverse probability weighting (IPW) to correct for confounding by indication.



602 patients were eligible for analysis (263 primary; 339 secondary surgery). Overall, 34 recurrences were observed (5.6%). After adjusting with IPW, no differences were observed between primary and secondary surgery for the presence of LNM (OR 0.97; 95% CI 0.49 to 1.93; p=0.940) and recurrence during follow-up (HR 0.97; 95% CI 0.41 to 2.34; p=0.954). Further adjusting for lymphovascular invasion, depth of invasion and number of retrieved lymph nodes did not alter this outcome.



Our data do not support an increased risk of LNM or recurrence after secondary surgery compared with primary surgery. Therefore, an attempt for an en-bloc resection of a possible T1 CRC without evident signs of deep invasion seems justified in order to prevent surgery of low-risk T1 CRC in a significant proportion of patients.
Department of Gastroenterology & Hepatology, University Medical Center Utrecht, Utrecht, The Netherlands.
A
A
Overwater
Department of Gastroenterology & Hepatology, University Medical Center Utrecht, Utrecht, The Netherlands.|Department of Gastroenterology & Hepatology, Flevohospital, Almere, The Netherlands.
K
K
Kessels
Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
S G
SG
Elias
Department of Gastroenterology & Hepatology, University Medical Center Utrecht, Utrecht, The Netherlands.
Y
Y
Backes
Department of Gastroenterology & Hepatology, Rijnstate, Arnhem, The Netherlands.
B W M
BWM
Spanier
Department of Gastroenterology & Hepatology, Amphia Hospital, Breda, The Netherlands.
T C J
TCJ
Seerden
Department of Gastroenterology & Hepatology, Meander Medical Center, Amersfoort, The Netherlands.
H J M
HJM
Pullens
Department of Gastroenterology & Hepatology, Isala, Zwolle, The Netherlands.
W H
WH
de Vos Tot Nederveen Cappel
Department of Gastroenterology & Hepatology, University Medical Center Utrecht, Utrecht, The Netherlands.
A
A
van den Blink
Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands.
G J A
GJA
Offerhaus
Department of Gastroenterology & Hepatology, Gelderse Vallei, Ede, The Netherlands.
J
J
van Bergeijk
Department of Gastroenterology & Hepatology, Groene Hart Hospital, Gouda, The Netherlands.
M
M
Kerkhof
Department of Gastroenterology & Hepatology, Diakonessenhuis Utrecht, Utrecht, The Netherlands.
J M J
JMJ
Geesing
Department of Gastroenterology & Hepatology, St. Jansdal Harderwijk, Harderwijk, The Netherlands.
J N
JN
Groen
Department of Gastroenterology & Hepatology, St. Antonius Hospital, Nieuwegein, The Netherlands.
N
N
van Lelyveld
Department of Gastroenterology & Hepatology, Deventer Hospital, Deventer, The Netherlands.
F
F
Ter Borg
Department of Gastroenterology & Hepatology, Albert Schweitzer Hospital, Dordrecht, The Netherlands.
F
F
Wolfhagen
Department of Gastroenterology & Hepatology, University Medical Center Utrecht, Utrecht, The Netherlands.
P D
PD
Siersema
Department of Gastroenterology & Hepatology, Isala, Zwolle, The Netherlands.
M M
MM
Lacle
Department of Gastroenterology & Hepatology, University Medical Center Utrecht, Utrecht, The Netherlands.
L M G
LMG
Moons
D000230:Adenocarcinoma / Q000556:secondary* / Q000601:surgery*; D000368:Aged; D003113:Colonoscopy / Q000009:adverse effects; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging; D011183:Postoperative Complications / Q000209:etiology; D012086:Reoperation / Q000009:adverse effects; D012307:Risk Factors; D013997:Time Factors
COLONIC POLYPS; COLONOSCOPY; COLORECTAL CARCINOMA; COLORECTAL SURGERY; THERAPEUTIC ENDOSCOPY