Persistent ymrEMVI and ymrTD on post-neoadjuvant MRI predict inferior disease-free and overall survival in rectal cancer patients

BACKGROUND: Extramural venous invasion (EMVI) and tumour deposits (TDs) are recognised markers of aggressive rectal cancer biology at baseline. However, their prognostic relevance when persisting on post-neoadjuvant MRI remains poorly defined. We performed a systematic review and meta-analysis to evaluate the oncologic impact of persistent MRI-detected EMVI (ymrEMVI) and tumour deposits (ymrTD) and to compare their predictive value with post-treatment nodal status. METHODS: PubMed, Embase, Web of Science, and Cochrane Library were searched from inception to December 2025. Studies reporting post-neoadjuvant MRI assessment of EMVI and/or TDs with time-to-event outcomes were included. Random-effects meta-analyses generated pooled hazard ratios (HRs) for disease-free survival (DFS), overall survival (OS), distant metastasis-free survival, and local recurrence-free survival. RESULTS: Seventeen studies encompassing 3932 patients met inclusion criteria. Persistent ymrEMVI was strongly associated with inferior DFS (HR 2.12, 95% CI 1.75-2.56) and OS (HR 2.21, 95% CI 1.63-2.99). ymrTD positivity conferred an even greater adverse impact on DFS (HR 2.85, 95% CI 1.58-5.17) and OS (HR 2.12, 95% CI 1.20-3.74). In contrast, post-treatment nodal status demonstrated inconsistent associations with DFS across studies. These vascular invasion phenotypes showed stronger and more reproducible prognostic value than residual nodal disease. CONCLUSIONS: Persistent EMVI and tumour deposits on post-neoadjuvant MRI identify a high-risk biological subgroup with markedly inferior survival, outperforming nodal status as prognostic indicators. Incorporation of ymrEMVI and ymrTD into post-treatment risk stratification and trial design is urgently required to guide intensification strategies and personalise rectal cancer management.