Outcomes of pT1 colorectal cancers (CRC) managed by Speedboat-assisted endoscopic submucosal dissection (ESD)

Aims The introduction of bowel cancer screening programs has led to increased diagnosis of pT1 CRC. Several national guidelines exist, but the optimal management of these lesions is still disputed. We review the outcomes of pT1 CRC managed by Speedboat-assisted ESD at our tertiary referral centre in the UK, to identify potential trends in guiding management post ESD.

Methods Retrospective analysis of patients undergoing ESD for pT1 CRC between September 2019 to October 2024 was performed. Data was collected from a centralised electronic health record system by reviewing endoscopy, histology, imaging reports and patient notes.

Results 24 cases were identified, representing 15% of ESD patients at our hospital. There were 19 rectal and 5 non-rectal lesions. All lesions had a nodular (Paris 0-1s) component apart from one flat (Paris 0-2a) lesion. Nodular lesions were all adenocarcinomas, whilst the flat lesion was anal intraepithelial neoplasia. En-bloc resection was achieved in 21 (87.5%) patients. Cases were stratified into low, local, or high-risk categories according to European Society of Gastrointestinal Endoscopy (ESGE) guidelines. Curative resection (defined as low-risk), was achieved in 7 (29%) patients. There were 5 local-risk and 11 high-risk patients. Contrasting ESGE guidance, 2 local-risk patients were managed surgically. One had surgery after initial histology reported probable lympho-vascular invasion (LVI) and R1 margins. However, the deep margin was clear by 0.8mm (R0+), and supplementary histology did not show definite LVI. Another was offered surgery due to indeterminate resection margins (Rx), as the multi-disciplinary team agreed on a more aggressive approach for a young patient. All high-risk patients were offered surgery: 7 accepted, 2 opted for chemoradiotherapy, and a further 2 for surveillance. There was no residual tumour on any surgical specimen and only 1 had positive lymph nodes. This patient had grade 3 budding, LVI and deep margin involvement in the ESD specimen. 1 patient suffered anastomotic dehiscence and sepsis post-op, while 4 patients had delayed complications including low anterior resection syndrome, sexual dysfunction and prolapsed stoma. All high-risk patients who declined surgery remain in remission after a mean 28-month follow-up period.

Conclusions Nodular morphology and distal lesions are predictive of submucosal invasive cancer, consistent with published data. Risk stratification of pT1 CRC based on existing guidelines does not accurately predict true need for surgery. None of the high-risk patients managed surgically had any residual tumour, and 5 patients suffered complications related to surgery. Additionally, high-risk patients who declined surgery remain in remission to date. ESD is potentially curative, even with high-risk features present. Deep resection margins<1mm alone, may not predict the true need for surgery and further research is needed to define characteristics that do.

Publication History

Article published online:
27 March 2025