Is There Place for an Exclusive Endoscopic Resection of High-Risk Malignant Colorectal Polyps?

Aims Endoscopically resected malignant colorectal polyps (pT1) have a significant risk of residual cancer in the bowel wall and nodal metastasis that depends on non-uniform histological features. We aimed to evaluate the frequency of unfavourable features in pT1 endoscopically resected and their correlation with residual cancer in the bowel wall and/or lymph nodes involvement.

Methods Single centre prospective cohort study including high-risk pT1 endoscopically resected between 2013 and 2019. pT1 polyps were classified as high-risk if they had any of the following: poor differentiation; piecemeal resection; Haggitt 4 for pedunculated polyps and Kikuchi 2/3 for non-pedunculated polyps; lymphovascular invasion; tumour budding grades 2/3 or resection margins not assessed or <1mm. High-risk pT1 were submitted to adjuvant surgery, unless contraindication or patient refusal.

Results Included 93 patients, 67 % (n = 62) males with a median age of 66 (58-74) years old. The median size of lesions was 15 (11-24) mm, 50 % (n = 46) were located at the sigmoid. Piecemeal resection was performed in 23 % (n = 21), tumour budding grades 2/3 was present in 40 % (n = 37), resection margins non-assessed or <1mm in 42 % (n = 39), lymphovascular invasion in 10 % (n = 9), poor differentiation in 6 % (n = 6), Haggitt 4 in 3.2 % (n = 3) and Kikuchi 2/3 in 20.4 % (n = 19). Additional surgery was performed in 53 patients; of those, 72 % (38/53) had no bowel wall residual cancer or nodal involvement. Lesions with residual cancer in the bowel wall and/or lymph nodes involvement had more unfavourable features (3 vs. 2, p<0.01). In multivariate analysis, only lymphovascular invasion (OR: 16; 95 %CI: 1.5-176) and Haggitt 4 (OR: 1.01; 9 %CI: 1.0-1.02) were associated with residual cancer and/or lymph nodes involvement.

Conclusions In our cohort, in high-risk pT1 with just two unfavourable features but not including lymphovascular invasion or Haggitt 4, additional surgery could be dispensable. Further research is needed to enable better treatment decisions.

Citation: João M, Alves S, Saraiva S et al. eP213 IS THERE PLACE FOR AN EXCLUSIVE ENDOSCOPIC RESECTION OF HIGH-RISK MALIGNANT COLORECTAL POLYPS?. Endoscopy 2021; 53: S168.

Publication History

Article published online:
19 March 2021