Introduction:
Nowadays, various endoscopic resections including polypectomy, endoscopic mucosal resection (EMR), and endoscopic submucosal dissection (ESD) are well known first-line approaches for early neoplastic rectal tumors.

Material and methods:
In this case series study, we analyzed 320 ESD procedures performed in a high-volume colorectal center in Poland, Europe. The aim of this study was to retrospectively evaluate ESD procedure in cases of rectal carcinoma performed by a single trained operator in a referral center provided with endoscopy.

Results:
Overall, en bloc resection was observed in 92.5% of patients (296/320). The en bloc resection rate was at a similar level in those lesions with involved anal sphincters versus tumors without involvement (93.85% vs. 92.16%; p=0.644). R0 resection was noted in 89.4% of patients (286/320). The overall curative ESD rate was 85.94% (n=275). The curative ESD rate in the invasive cancer group reached 52.6% (n=20). We observed ESD-related adverse events, such as bleeding and perforation, in 3.4 % of patients (n=11).

Conclusions:
We have demonstrated that ESD in rectal tumors is an efficient and safe procedure with a high curative rate, even in difficult lesions. Anal sphincter localization and recurrent character of the lesion have no impact on the final outcomes. The ESD approach should have been considered for all rectal tumors, especially those lesions suspected of superficial mucosal invasion, as it can serve as a staging method and may have been curative for adenomas and cancers limited to mucosa.