Clinical application of endoscopic submucosal dissection for superficially invasive squamous cell carcinoma/high-grade squamous intraepithelial lesion involving the canal anal.

Background: Superficially invasive squamous cell carcinoma (SISCC) and high-grade squamous intraepithelial lesions (HSIL) involving the anal canal are rare, and their surgical management involves local excision. Endoscopic submucosal dissection (ESD) has recently emerged as a promising treatment. This study aimed to evaluate the feasibility and safety of ESD for SISCC and HSIL in the anal canal.

Methods: All patients diagnosed with SISCC or HSIL in the anal canal who underwent ESD between November 2018 and May 2023 were included. Patient age, sex, pathology, human immunodeficiency virus (HIV) status, human papillomavirus (HPV) status, T stage, en bloc rate, and R0 resection rate were analyzed.

Results: Ten patients, including two men and eight women, with a median age of 61 (51-68) years were enrolled. All patients were HIV-negative, but five (50%) were HPV-positive. Pathological examination showed tumor stage of two patients as T2, one as T0 of SISCC, and seven as Tis of HSIL. The median specimen and tumor sizes were 24 (6-65) mm and 18 (6-55) mm, respectively. The en bloc and R0 resection rates were 100% and 80%, respectively. No severe complications occurred and no recurrence was observed at the follow-up (median follow-up period, 9 (1-35) months).

Conclusions: ESD is a reliable and minimally invasive procedure that enables more individualized treatment options for specific groups. As we were limited by the length of the observation period, the long-term performance of ESD for SISCC and HSIL involving the anal canal requires further investigation.