Long-Term Outcomes After Endoscopic Resection for Strictly Defined Ulcerative Colitis-Associated Neoplasia: An...

Ulcerative colitis (UC)-associated neoplasia (UCAN) carries a risk of metachronous development; however, risk stratification based on inflammatory origin remains unclear. This exploratory study aimed to classify UCAN arising in colitis-affected areas and to evaluate long-term outcomes after endoscopic resection (ER).

We retrospectively analyzed the data of 102 patients with UC who underwent ER for colorectal neoplasia between 2004 and 2024. Lesions in colitis-affected areas were operationally classified as confirmed UCAN, based on non-polypoid morphology and characteristic p53 and Ki-67 immunostaining patterns, or as probable UCAN. Lesions in colitis-unaffected areas were classified as sporadic neoplasia (SN). Cumulative incidences of metachronous neoplasia and overall survival were estimated using the Kaplan-Meier method, and associations with metachronous confirmed UCAN were assessed using univariate Cox proportional hazards models.

The median follow-up period was 4.3 years. Among 102 lesions, 13 were classified as confirmed UCAN, 68 as probable UCAN, and 21 as SN. The 5-year cumulative incidence of metachronous confirmed UCAN was significantly higher in the confirmed UCAN group (52%) than in the probable UCAN (4%) and SN (0%) groups (p < 0.01). Confirmed UCAN remained independently associated with metachronous confirmed UCAN (hazard ratio, 11.05; 95% confidence interval, 2.01-60.7; p < 0.01). Overall survival did not differ significantly among groups.

Using an exploratory classification, confirmed UCAN was associated with an increased incidence of metachronous neoplasia after ER. These findings suggest that this subgroup may warrant closer surveillance; however, further validation is required.