Endoscopic submucosal dissection for nonpedunculated submucosal invasive colorectal cancer: is it feasible?

Background/aims: There have been no definite indications for additional surgical resection after endoscopic submucosal dissection (ESD) of submucosal invasive colorectal cancer (SICC). The aims of this study were to evaluate the feasibility of ESD for nonpedunculated SICC and to determine the need for subsequent surgery after ESD.
Patients and Methods: A total of 150 patients with nonpedunculated SICC in resected specimens after ESD were analyzed. Among them, 75 patients underwent subsequent surgery after ESD. Clinical outcomes of ESD and histopathological risk factors for lymph node (LN) metastasis were evaluated.
Results: The en-bloc resection and complete resection (R0) rates of ESD were 98% (147/150) and 95.3% (143/150), respectively. None of the patients had delayed bleeding after ESD. Perforations occurred in seven patients (4.7%), which were successfully treated by endoscopic clipping. After subsequent surgery for 75 patients, LN metastases were found in 10 cases (13.3%). The incidence of LN metastasis was significantly higher in tumors featuring submucosal invasion of at least 1500 μm, lymphovascular invasion, and tumor budding. Multivariate analysis showed that lymphovascular invasion (P=0.034) and tumor budding (P=0.015) were significantly associated with LN metastasis. Among the 150 patients, no local recurrence or distant metastasis was detected, except one patient with risk factors and who refused subsequent surgery, during the overall median follow-up of 34 months (range, 5-63 months).
Conclusion: ESD is feasible and may be considered as an alternative treatment option for carefully selected cases of nonpedunculated SICC, provided that the appropriate histopathological curative criteria are fulfilled in completely resectable ESD specimens.