546P - Differential of the nutritional index before and after neoadjuvant chemoradiotherapy as a prognostic factor of recurrence in patients with locally advanced adenocarcinoma of the rectum

The Nutritional Prognostic Index (INP) is a nutritional and immunological marker. The difference between concomitant pre and post chemoradiotherapy INP and its impact as a prognostic factor for recurrence in patients with locally advanced rectal adenocarcinoma remains unclear. With the aim of providing greater evidence of the recurrent prognostic role of the differential of the pre and post INP in patients with locally advanced rectal adenocarcinoma we carried out the present study. Of the total of 206 patients, 74 patients were excluded. The analysis included 132 patients. INP formula: 10 * serum albumin (g / dL) + 0.005 * total lymphocyte count (per mm3). The INP values were determined in 2 points: before QT/RTneoadjuvant (preQT/RT INP ) and after the neoadjuvant QT/RT termination, (postQT/RT PNI). The difference in INP (dINP) was calculated with the formula: preQT/RT INP - postQT/RT INP. Table546P Univariate and multivariate analysisTableUnivariateMultivariateFactorPHRIC 95%PGender0.3761.4090.657 – 3.020.378Age0.0370.9690.940 – 0.9980.039body mass index0.0750.6340.382 – 1.0520.078Degree Differentiation0.3561.1790.697 – 2.020.550ypT0.1521.10.646 – 1.920.697ypN0.1021.280.947 – 1.750.106Diferencial INP0.1211.420.906 – 2.230.126ECOG0.0083.41.26 – 9.60.016 In the Kaplan and meier analysis, recurrence free survival (SLR) was P=0.03. Independent factors for recurrence were age and ECOG (95% CI 0.940 – 0.998¸ P=0.037, HR 3.4 95% IC 1.26 – 9.6, P=0.016). Our findings showed a better SLR in the low dINP subgroup, so we took it as a cutoff 5. Patients who presented a dINP less than 5, have a better SLR in relation to those who have a dINP > 5. P=0.013. The difference less than 5 between the nutritional index before and after neoadjuvant chemoradiotherapy in patients with locally advanced adenocarcinoma of the rectum is associated with an increase in SLR as an independent predictor of recurrence. The authors. Has not received any funding. All authors have declared no conflicts of interest.