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Updated: Aug 6, 2026
Robot-assisted Total Mesorectal Excision and Lateral Pelvic Lymph Node Dissection for Locally Advanced Middle-low Rectal Cancer
Published on: February 12, 2022
From imaging to action: MRI features direct surgical strategy in low rectal cancer
Junzhe Tang1, Ruiqi Gu1, Shiqi Hu1
1Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
Background:
Surgical choice between Dixon and Miles procedures in low rectal cancer (LRC) remains controversial, especially for tumors located 3-5 cm from the anal verge-a clinical "gray zone." This study aims to compare oncologic outcomes between procedures and identify prognostic factors.
Methods:
We retrospectively analyzed 1,215 LRC patients (≤6 cm from anal verge) treated from 2008 to 2020. Patients in the 3-5 cm range (n = 601) formed the Borderline Group. MRI-based risk factors (mrMRF, mrEMVI) and survival outcomes were assessed using Kaplan-Meier and Cox regression models.
Results:
MRI-based risk stratification revealed distinct survival differences. Patients with MRI-defined high-risk features derived significant oncologic benefit from the Miles procedure. In the mrMRF-positive subgroup, Miles surgery was associated with improved disease-free survival (DFS; HR = 0.28, P = 0.004) and overall survival (OS; HR = 0.21, P < 0.001) compared with Dixon. Similarly, in mrEMVI-positive patients, Miles resulted in superior DFS (HR = 0.38, P = 0.012) and OS (HR = 0.25, P < 0.001). Multivariate analysis further confirmed that Miles was an independent predictor of favorable survival in these high-risk subgroups, whereas outcomes were comparable between procedures in MRI low-risk patients.
Conclusion:
For borderline LRC cases (3-5 cm from anal verge), Dixon and Miles surgeries yield similar outcomes overall. However, Miles surgery is preferable in patients with MRI-defined high-risk features, supporting MRI-guided surgical decision-making. These findings highlight the clinical utility of an MRI-guided, risk-adapted surgical strategy for borderline low rectal cancer.
