Effects of prior endoscopic resection on recurrence in patients with T1 colorectal cancer who underwent radical surgery

Approaches and considerations in the endoscopic treatment of T1 colorectal cancer

The detection of early colorectal cancer (CRC) is increasing through the implementation of screening programs. This increased detection enhances the likelihood of minimally invasive surgery and significantly lowers the risk of recurrence, thereby improving patient survival and reducing mortality rates. T1 CRC, the earliest stage, is treated endoscopically in cases with a low risk of lymph node metastasis (LNM). The advantages of endoscopic treatment compared with surgery include minimal invasiveness and limited tissue disruption, which reduce morbidity and mortality, preserve bowel function to avoid colectomy, accelerate recovery, and improve cost-effectiveness. However, T1 CRC has a risk of LNM. Thus, selection of the appropriate treatment between endoscopic treatment and surgery, while avoiding overtreatment, is challenging considering the potential for complete resection, LNM, and recurrence risk.

Completion Surgery after Non-Curative Local Resection of Early Rectal Cancer

Background

The expanding indications of local - endoscopic and transanal surgical - resection of early rectal cancer has led to their increased popularity and inclusion in the treatment guidelines. The accuracy of the current diagnostic tools in identifying the low-risk T1 tumors that can be curatively treated with a local resection is low, and thus several patients require additional oncologic surgery with total mesorectal excision (TME). An efficient clinical strategy which avoids overtreatment and obstacle surgical procedures is under debate between different disciplines.

Summary

Completion surgery has comparable outcomes to primary surgery regarding perioperative morbidity and mortality but also recurrence rates and overall survival. However, local scarring in the mesorectum can make mesorectal excision technically challenging, especially after full-thickness resections, and has been associated with increased rates of permanent ostomy and worse quality of the TME specimen. This risk seems to be lower after muscle-sparing procedures like endoscopic submucosal dissection, which seem to show a benefit in comparison to full-thickness resections.

Key Messages

Completion surgery after non-curative local resection of gastrointestinal malignancies is safe and feasible. Full-thickness resection techniques can cause scarring of the mesorectum; therefore, muscle-sparing procedures should be preferred.

Impact of surgery after endoscopically resected high-risk T1 colorectal cancer: results of an emulated target trial

BACKGROUND AND AIMS

We aimed to compare the long-term outcomes of patients with high-risk T1 colorectal cancer (CRC) resected endoscopically who received either additional surgery or surveillance.

METHODS

We used data from routine care to emulate a target trial aimed at comparing 2 strategies after endoscopic resection of high-risk T1 CRC: surgery with lymph node dissection (treatment group) versus surveillance alone (control group). All patients from 14 tertiary centers who underwent an endoscopic resection for high-risk T1 CRC between March 2012 and August 2019 were included. The primary outcome was a composite outcome of cancer recurrence or death at 48 months.

RESULTS

Of 197 patients included in the analysis, 107 were categorized in the treatment group and 90 were categorized in the control group. From baseline to 48 months, 4 of 107 patients (3.7%) died in the treatment group and 6 of 90 patients (6.7%) died in the control group. Four of 107 patients (3.7%) in the treatment group experienced a cancer recurrence and 4 of 90 patients (4.4%) in the control group experienced a cancer recurrence. After balancing the baseline covariates by inverse probability of treatment weighting, we found no significant difference in the rate of death and cancer recurrence between patients in the 2 groups (weighted hazard ratio, .95; 95% confidence interval, .52-1.75).

CONCLUSIONS

Our study suggests that patients with high-risk T1 CRC initially treated with endoscopic resection may not benefit from additional surgery.