AIM: To evaluate risk factors for local recurrence after endoscopic mucosal resection of colorectal adenomas > 20 mm.METHODS: Retrospective data analysis of 216 endoscopic mucosal resections for colorectal adenomas > 20 mm in 179 patients(40.3% female; median age 68 years; range 35-91 years). All patients had at least 1 follow-up endoscopy with a minimum control interval of 2 mo(mean follow-up 6 mo/2.0-43.4 mo). Possible factors associated with local recurrence were analyzed by univariate and multivariate analysis. RESULTS: Median size of the lesions was 30 mm(20-70 mm),69.0% were localized in the right-sided(cecum,ascending and transverse) colon. Most of the lesions(85.6%) showed a non-pedunculated morphology and the majority of resections was in piecemeal technique(78.7%). Histology showed carcinoma or high-grade intraepithelial neoplasia in 51/216(23.6%) lesions including 4 low risk carcinomas(pT1 a,L0,V0,R0- G1/G2). Histologically proven recurrence was observed in 33/216 patients(15.3%). Patient age>65 years,polyp size>30 mm,non-pedunculated morphology,localization in the right-sided colon,piecemeal resection and tubular-villous histology were found as associated factors in univariate analysis. On multivariate analysis,only localization in the rightsided colon(HR = 6.842/95%CI:1.540-30.394; P=0.011),tubular-villous histology(HR = 3.713/95%CI: 1.617-8.528;P=0.002) and polyp size>30 mm(HR=2.563/95%CI:1.179-5.570; P=0.017) were significantly associated risk factors for adenoma recurrence. CONCLUSION: Meticulous endoscopic follow-up is warranted after endoscopic mucosal resection of adenomas localized in the right-sided colon larger than > 30 mm,with tubular-villous histology. AIM: To evaluate risk factors for local recurrence after endoscopic mucosal resection of colorectal adenomas> 20 mm. METHODS: Retrospective data analysis of 216 endoscopic mucosal resections for colorectal adenomas> 20 mm in 179 patients (40.3% female; median age 68 years; range All patients had at least 1 follow-up endoscopy with a minimum control interval of 2 mo (mean follow-up 6 mo / 2.0-43.4 mo). Possible factors associated with local recurrence were analyzed by univariate and multivariate analysis. RESULTS: Median size of the lesions was 30 mm (20-70 mm), 69.0% were localized in the right-sided (cecum, ascending and transverse) colon. Most of the lesions (85.6%) showed a non-pedunculated morphology and the majority of resections was in piecemeal technique (78.7%). Histology showed carcinoma or high-grade intraepithelial neoplasia in 51/216 (23.6%) lesions including 4 low risk carcinomas (pT1 a, L0, V0, G2). Histologically proven recurrence was observed in 33/216 patients (1 5.3%). Patient age> 65 years, polyp size> 30 mm, non-pedunculated morphology, localization in the right-sided colon, piecemeal resection and tubular-villous histology were found as associated factors in univariate analysis. On multivariate analysis, only localization in the rightsided colon (HR = 6.842 / 95% CI: 1.540-30.394; P = 0.011), tubular-villous histology (HR = 3.713 / 95% CI: 1.617-8.528; (HR = 2.563 / 95% CI: 1.179-5.570; P = 0.017) were significantly associated risk factors for adenoma recurrence. CONCLUSION: Meticulous endoscopic follow-up is warranted after endoscopic mucosal resection of adenomas localized in the right-sided colon larger than > 30 mm, with tubular-villous histology.