Patient outcomes after non-curative endoscopic submucosal dissection for early colorectal cancer: a single-center, retrospective cohort study

BACKGROUND: The treatment patterns and outcomes for patients after non-curative endoscopic submucosal dissection (ESD) remain controversial, particularly among those requiring preservation of the anal sphincter or advanced age. This retrospective study aimed to investigate the treatment patterns and outcomes in patients after non-curative ESD for early colorectal cancer (CRC). METHODS: This was a retrospective review in Chinese patients who received non-curative ESD for early CRC, and who were treated in the Cancer Hospital at the Chinese Academy of Medical Sciences from 2010 to 2019. Demographic parameters, clinicopathologic features, treatment patterns, and clinical outcomes were analyzed. RESULTS: Of the 180 patients who received non-curative ESD, 85 received additional surgery; the remaining 95 patients were kept under surveillance only. Patients in the surveillance-only group tended to be older than those in the additional surgery group. Furthermore, tumors in the surveillance-only group were located in the rectum significantly more often, were better differentiated with a shallower depth of invasion and less perineuronal invasion than in the additional surgery group; there were fewer high-risk factors for residual cancer or lymph node (LN) metastasis in the surveillance-only group compared with the additional surgery group. There was no significant difference in 5-year overall survival (OS) (92.6% versus 92.7%, P=0.355), 5-year disease-free survival (DFS) (94.7% versus 91.9%, P=0.340), 5-year cancer-specific survival (CSS) (93.8% versus 92.7%, P=0.791), or total recurrence rates (4.7% versus 9.5%, P=0.217) between the additional surgery and surveillance-only groups, respectively. CONCLUSIONS: ESD results in favorable outcomes for patients with early CRC. Surveillance in patients who receive non-curative ESD may be an alternative option for those with advanced age and fewer high-risk factors for residual cancer or LN metastasis.