Organ Preservation in MSS Rectal Cancer

Area of Science:

• Oncology
• Gastroenterology
• Surgical Oncology

Background:

• Rectal cancer exhibits diverse genetic and molecular subtypes.
• Neoadjuvant therapy improves response rates in microsatellite stable (MSS) rectal cancer.
• MSS rectal cancer shows limited response to immune checkpoint inhibitors alone.

Purpose of the Study:

• To evaluate organ preservation as an alternative to radical surgery for MSS rectal cancer.
• To assess the feasibility and outcomes of nonoperative management after neoadjuvant therapy.
• To identify patient selection strategies for maximizing organ preservation success.

Main Methods:

• Review of neoadjuvant treatment outcomes in MSS rectal cancer.
• Analysis of organ preservation strategies including nonoperative management and surgery.
• Comparison of oncological and morbidity outcomes between organ preservation and radical surgery.

Main Results:

• Organ preservation is feasible for patients achieving clinical complete response (cCR) or near-cCR after neoadjuvant treatment.
• Oncological outcomes appear noninferior to radical surgery with significantly lower postoperative morbidity.
• Patient selection, either pre- or post-treatment, is crucial for favorable outcomes.

Conclusions:

• Organ preservation represents a safe and effective strategy for select MSS rectal cancer patients.
• Nonoperative management and organ preservation surgery offer a promising alternative to radical resection.
• Further research is warranted to optimize tumor regression and expand organ preservation possibilities.