Establishment and validation of nomograms for predicting mesorectal lymph node staging and restaging

Area of Science:

• Oncology
• Radiology
• Medical Imaging

Background:

• Accurate preoperative lymph node (LN) status determination is critical for rectal cancer treatment planning.
• Lymph node metastasis (LNM) significantly impacts patient prognosis and therapeutic strategies.
• Current imaging modalities require refinement for precise nodal staging.

Purpose of the Study:

• To prospectively evaluate risk factors for lymph node metastasis (LNM) in rectal cancer.
• To construct and validate nomograms for predicting LNM using MRI and clinical data.
• To enhance the diagnostic accuracy of preoperative N staging and restaging for rectal cancer.

Main Methods:

• Prospective enrollment of rectal cancer patients undergoing preoperative MRI (July 2021-July 2022).
• Node-by-node comparison of MRI findings with histopathology from surgical specimens.
• Multivariate logistic regression analysis to identify risk factors and develop nomograms, validated using calibration plots and concordance index.

Main Results:

• Nomograms integrating clinical and MRI features demonstrated high diagnostic value (AUC 0.855-0.915) in predicting LNM.
• Key predictors included short diameter, CEA level, mrT-stage, border contour, signal intensity, and MRI-EMVI.
• Good agreement was observed between predicted and actual probabilities in both training and validation cohorts.

Conclusions:

• Developed nomograms combining preoperative clinical and imaging biomarkers significantly improve prediction of nodal involvement in rectal cancer.
• These nomograms serve as a valuable reference for preoperative N staging and restaging.
• Enhanced prediction accuracy aids in optimizing treatment strategies and patient management.