Seven Years of Watch and Wait With Rectal Cancer-Reflections and Optimisations.

Area of Science:

• Oncology
• Gastroenterology
• Surgical Oncology

Background:

• Rectal adenocarcinoma treatment often involves neoadjuvant therapy followed by surgery.
• The Watch and Wait (W&W) approach is an organ-preserving strategy for patients achieving a clinical complete response (cCR) after neoadjuvant treatment.
• Rigorous surveillance is crucial for patients managed with W&W.

Purpose of the Study:

• To report updated outcomes of the W&W strategy for rectal adenocarcinoma at Sir Charles Gairdner Hospital (SCGH).
• To present a revised treatment pathway and surveillance protocol based on updated results.

Main Methods:

• Retrospective review of a prospectively maintained database and medical records (2017-2023).
• Inclusion of patients referred for long-course chemoradiotherapy (LCCRT) for rectal adenocarcinoma with curative intent.
• Analysis of patients managed under the W&W strategy following LCCRT.

Main Results:

• 24% of patients referred for LCCRT achieved cCR, with 84% sustaining it.
• 16% of W&W patients experienced suspected local regrowth, detected early by surveillance.
• Surgical salvage was successful in all regrowth cases; 20% of patients undergoing surgery had a pathological complete response (pCR) despite not having a cCR.

Conclusions:

• The W&W strategy is effective for rectal adenocarcinoma, with high rates of sustained cCR.
• The SCGH surveillance protocol enables early detection of regrowth, facilitating successful surgical salvage.
• Optimizations in patient selection and surveillance intensity are proposed to refine the W&W approach.