Objective:

To compare the perioperative efficacy and safety of short-course radiotherapy combined with immunochemotherapy (SCRT + ICT) versus conventional neoadjuvant chemoradiotherapy (NCRT) in patients with proficient mismatch repair (pMMR) rectal cancer, focusing on primary endpoints such as pathological complete response (pCR) and anal preservation rates.

Key Findings:

• SCRT + ICT showed improved pathological complete response (pCR) rates compared to NCRT (p < 0.05).
• The anal preservation rate was significantly higher in patients receiving SCRT + ICT (p < 0.05).
• SCRT + ICT demonstrated a favorable safety profile with manageable perioperative complications.

Interpretation:

The combination of SCRT and ICT may enhance treatment outcomes in pMMR rectal cancer, making it a promising approach for improving surgical options and patient prognosis, potentially influencing future treatment guidelines.

Limitations:

• The study is retrospective and may be subject to selection bias, which could affect the generalizability of the findings.
• Variability in treatment regimens and timing complicates the assessment of individual contributions of therapies, potentially obscuring the true efficacy of SCRT + ICT.

Conclusion:

SCRT combined with immunochemotherapy is a promising strategy for improving perioperative outcomes in patients with proficient mismatch repair rectal cancer.