P-207 Correlation between extramural vascular invasion (EMVI) and systemic inflammatory response markers in rectal cancer

Colorectal cancer (CRC) is the leading cause of cancer-related death worldwide. Rectal constitutes around one-third all CRCs. The current standard care patients with locally advanced rectal neoadjuvant radio/chemo-radiotherapy; however, treatment differs substantially across countries. Novel markers are required to optimize treatment. Extramural vascular invasion (EMVI) a well-established magnetic resonance imaging (MRI)-based negative prognostic marker. Systemic inflammatory response such as lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte (NLR) or platelet-to-lymphocyte (PLR) novel blood-based in many cancers, including CRC. We hypothesized if there relation between LMR, NLR, PLR and presence EMVI on pre-treatment MRI. conducted retrospective analysis 231 treated Maria Sk?odowska-Curie National Research Institute Oncology, Warsaw, Poland August 2016 January 2021. inclusion criteria were follows: 1) histologically confirmed cancer; 2) staging high-resolution MRI scan pelvis evaluation status by an experienced radiologist; 3) clinical records demographic laboratory data available complete. exclusion were: distant metastases at time diagnosis; chemotherapy and/or radiotherapy applied prior MRI; malignant tumors other organs; 4) hematologic malignancies disorders that could affect markers; 5) immunosuppressive therapy. Sixty-three found eligible for study. analyzed routine blood examination each patient calculated their NLR PLR. median was 10 days. Thirty (47.6%) EMVI-positive 33 (52.4%) EMVI-negative. There correlation stage disease (p = 0.034). No significant differences detected EMVI-negative groups regarding level According ROC (Receiver Operating Characteristic) analyses do not differentiate terms EMVI; AUC (area under curve) LMR 0.45 (95% CI 0.30; 0.60); 0.53 0.38; 0.68) 0.55 0.40; 0.69), neither these parameters good predictor EMVI. In conclusion, we no locally-advanced cancer.