ESD in Locally Advanced Rectal Cancer Following CRT

Colorectal cancer (CRC) represents a significant health challenge in Egypt. According to GLOBOCAN 2020, rectal cancer ranks sixth in all cancers among males and females, with 5,231 new cases, accounting for 3.9% of all cancers. El-Moselhy et al., 2025 reported that the rectum was involved in up to 20% of CRC cases in Egypt .

In recent years, there was a shift in management of locally advanced rectal cancer (LARC) toward organ preserving strategies. After neoadjuvant chemoradiotherapy (CRT) or total neoadjuvant therapy (TNT), a notable proportion of patients achieve a clinical complete response (cCR) or near-complete response (nCR) making them candidates for either structured watch-and-wait (W&W) surveillance or selective local interventions designed to avoid total mesorectal excision (TME) .

In phase II OPRA trial, long-term organ preservation was achieved in approximately 50% of participants, with most tumor regrowth occurring within the first two years.

Despite that, small residual mucosal/submucosal lesions with cCR post CRT are still challenging in management with either W&W or ESD. Endoscopic submucosal dissection (ESD) offers en-bloc resection, comprehensive histopathologic evaluation (depth of invasion, lymphovascular invasion, budding, margins), and the option of salvage surgery if needed. Early evidence supports its feasibility and safety in this setting .

One meta-analysis confirms strong effectiveness and low rate of recurrence when ESD is used for residual or recurrent lesions with prior surgery or endoscopy.

Inclusion criteria

• Adult patients with rectal adenocarcinoma who underwent full course locoregional chemoradiotherapy with organ-preservation intent.

Post-CRT assessment showing either:

A. Small residual mucosal/submucosal lesion amenable to en-bloc ESD (CRT→ESD), OR B. Clinical/radiologic near-complete/complete response and decision to observe (CRT→Follow-up).

Exclusion criteria

• - Evidence of distant metastasis at post-CRT restaging.
• Lesions unsuitable for endoscopic resection (circumferential, deeply invasive on EUS/MRI).
• Patients who had immediate TME after CRT for other reasons.
• Unfit for endoscopy or follow-up.