Outcome of Completion Surgery after Endoscopic Submucosal Dissection in Early-Stage Colorectal Cancer Patients

SIMPLE SUMMARY: Instead of extensive conventional surgical resection, early-stage colorectal cancers are now often primarily treated using specialized local resection techniques, such as the endoscopic submucosal dissection (ESD). Sometimes after ESD a regular surgical resection is still needed. However, the impact of ESD on this surgery has not been well studied yet. This study aimed to investigate if ESD affected the safety and outcome of completion surgery. Outcomes of two groups of patients were compared: one consisting of patients who only had an upfront surgical resection and another consisting of patients who had an ESD followed by a surgical resection. Results showed that safety and outcome of surgery were similar in both groups. This means that ESD does not significantly increase negative outcomes of surgery. This knowledge empowers doctors to perform ESD as a first treatment option for early-stage colorectal cancers. ABSTRACT: T1 colorectal cancers (T1CRC) are increasingly being treated by endoscopic submucosal dissection (ESD). After ESD of a T1CRC, completion surgery is indicated in a subgroup of patients. Currently, the influence of ESD on surgical morbidity and mortality is unknown. The aim of this study was to compare 90-day morbidity and mortality of completion surgery after ESD to primary surgery. The completion surgery group consisted of suspected T1CRC patients from a multicenter prospective ESD database (2014–2020). The primary surgery group consisted of pT1CRC patients from a nationwide surgical registry (2017–2019). Patients with rectal or sigmoidal cancers were selected. Patients receiving neoadjuvant therapy were excluded. Propensity score adjustment was used to correct for confounders. In total, 411 patients were included: 54 in the completion surgery group (39 pT1, 15 pT2) and 357 in the primary surgery group with pT1CRC. Adverse event rate was 24.1% after completion surgery and 21.3% after primary surgery. After completion surgery 90-day mortality did not occur, though one patient died in the primary surgery group. After propensity score adjustment, lymph node yield did not differ significantly between the groups. Among other morbidity-related outcomes, stoma rate (OR 1.298 95%-CI 0.587-2.872, p = 0.519) and adverse event rate (OR 1.162; 95%-CI 0.570-2.370, p = 0.679) also did not differ significantly. A subgroup analysis was performed in patients undergoing rectal surgery. In this subgroup (37 completion and 136 primary surgery), these morbidity outcomes also did not differ significantly. In conclusion, this study suggests that ESD does not compromise morbidity or 90-day mortality of completion surgery.