Clinical Report: MRI-Based Risk Assessment for Neoadjuvant Immunotherapy in Rectal Cancer
Overview
This study evaluates an MRI-based risk stratification system for predicting pathological complete response (pCR) in locally advanced rectal cancer (LARC) patients undergoing neoadjuvant immunotherapy. The findings suggest that MRI-defined high-risk patients may benefit more from neoadjuvant immunotherapy plus chemoradiotherapy compared to standard chemoradiotherapy.
Background
Locally advanced rectal cancer (LARC) poses significant treatment challenges due to high recurrence rates and variable responses to neoadjuvant therapies. Current standard care involves neoadjuvant chemoradiotherapy, yet the pCR rates remain suboptimal, underscoring the need for improved patient stratification. MRI has emerged as a critical tool in assessing tumor characteristics that may influence treatment outcomes.
An MRI-based risk score using mrEMVI, mrMRF, and tumor length ≥ 5 cm predicted pCR with an AUC of 0.835.
In the MRI high-risk group, pCR rates were significantly higher with nICRT compared to nCRT.
In the low-risk group, no significant difference in pCR rates was observed between nICRT and nCRT.
Interobserver agreement for MRI assessments was evaluated using Cohen’s kappa statistics.
Results suggest that MRI-based stratification may help identify patients likely to benefit from intensified neoadjuvant treatment.
Clinical Implications
The study highlights the potential of MRI-based risk stratification to guide treatment decisions in LARC patients, particularly in identifying those who may benefit from neoadjuvant immunotherapy. Clinicians should consider integrating MRI assessments into pre-treatment evaluations to optimize patient outcomes.
Conclusion
MRI-based risk assessment may enhance the identification of patients with LARC who are more likely to achieve pCR with neoadjuvant immunotherapy. Further prospective validation is necessary to confirm these findings before clinical implementation.
