Endoscopic Full-Thickness Resection for T1 Colorectal Cancers: Update on Short-Term Outcomes

Endoscopic full-thickness resection (eFTR) can be used for lesions <30 mm in size, and when used for early colorectal cancer (CRC), it provides a histologic specimen containing the entire submucosa and muscularis propia for histologic analysis. This Dutch study evaluated 330 procedures, of which 132 were primary resections for endoscopically suspected T1 CRC, and 198 were secondary scar resections after prior incomplete resection of T1 CRC. 

The primary T1 CRC resections were technically successful in 89.4%, with R0 resection in 82%. After primary resection, histology showed cancer in 85.2%, with T1 cancer in 89% and T2 in 11%. Of 97 T1 CRCs that were primarily resected, low-risk histologic features were present in 28%, but if deep submucosal invasion was excluded as a risk factor, potential curative resection rose from 24% to 61%. 

For secondary treatment, technical success was 85.4%, and R0 resection 88%. High R0 resection rates were achieved, regardless of previous R1, Rx, or R0 status. In the 192 secondary resections, cancer was found in 26. Of the 135 cancers found during both primary and secondary resections, histologic discrimination between high and low risk for residual cancer was feasible in 99.3%. 

There were 7 perforations: 2 direct and 5 delayed.

The overall curative resection rate (R0 without high-risk features of cancer) was 60.3%, including 32% for primary treatment of cancer (and including deep submucosal invasion alone as a high-risk feature) and 79% after secondary treatment.

Among 47 patients with oncologic surgical resections for high-risk features, 11 had residual cancer. There were 73 cases not scheduled for surgical resection, despite high-risk features, of which about half had deep submucosal invasion as the only histologic risk factor, and 41% had comorbidities or the patient refused. At endoscopic follow-up, residual lesion was present in 4%.