It is difficult to predict the presence of histological risk factors for lymph node metastasis before endoscopic treatment of T1 colorectal cancer.
Therefore, endoscopic therapy is propagated to obtain adequate histological staging.
Dr Moons and colleagues of the Netherlands examined whether secondary surgery following endoscopic resection of high-risk T1 colorectal cancer does not have a negative effect on patients' outcomes compared with primary surgery.
Patients with T1 colorectal cancer with one or more histological risk factors for lymph node metastasis 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.
|Overall, 34 recurrences were observed|
The doctors performed a propensity score analysis using inverse probability weighting to correct for confounding by indication.
The team identified 602 patients were eligible for analysis.
Overall, 34 recurrences were observed.
After adjusting with inverse probability weighting, no differences were observed between primary and secondary surgery for the presence of lymph node metastasis and recurrence during follow-up.
Further adjusting for lymphovascular invasion, depth of invasion and number of retrieved lymph nodes did not alter this outcome.
Dr Moons' team comments, "Our data do not support an increased risk of lymph node metastasis or recurrence after secondary surgery compared with primary surgery."
"Therefore, an attempt for an en-bloc resection of a possible T1 colorectal cancer without evident signs of deep invasion seems justified in order to prevent surgery of low-risk T1 colorectal cancer in a significant proportion of patients."