Baseline mrEMVI as an independent prognostic factor for locally advanced rectal cancer with neoadjuvant chemoradiotherapy: recommendations for risk stratification

Extramural venous invasion status is a potential prognostic factor for identifying rectal cancer patients with a high risk of distant metastasis or local recurrence. It is currently unclear what impact extramural venous invasion status as defined by magnetic resonance imaging before neoadjuvant chemoradiotherapy (pre-NCRT mrEMVI) has on survival outcomes in patients with locally advanced rectal cancer. Moreover, the incorporation of baseline mrEMVI into risk stratification is poorly understood.This study has demonstrated that pre-NCRT mrEMVI status can be reliably evaluated and can serve as an independent prognostic factor for distant and local recurrence and overall survival in patients with locally advanced rectal cancer. We have provided important evidence that pre-NCRT mrEMVI status should be considered for managing risk stratification in baseline locally advanced rectal cancer. Finally, we recommend that mrEMVI evaluation be included in routine pre-NCRT MR reports to support an individualized treatment strategy, considering positive pre-NCRT mrEMVI may serve as an indicator for neoadjuvant chemotherapy.