Factors associated with higher rate of Complete Pathologic Response after Long-Course Neoadjuvant Treatment for Locally Advanced Rectal Cancer Patients – Results from a retrospective cohort study focused on Inflammatory Indexes

BACKGROUND: Pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (NCRT) has a prognostic value in locally advanced rectal cancer (LARC). This study aimed to evaluate the ability to predict pCR using inflammatory markers, valuable to select the most adequate treatment strategy. METHODS: Patients undergoing primary tumor resection after long-cycle NCRT at a single center (2012 to 2018) were retrospectively collected (n=130). Patient demographics, preoperative laboratory measurements, tumor characteristics, treatment strategy and postoperative anatomopathologic variables were collected. The association of factors to CPR was examined using binary logistic regression and odds ratio (OR) (95% confidence interval) and the discriminative capacity with ROC curve. RESULTS: Out of 130 patients 42 pCRs occurred, a 32.3% of the sample. Variables identified as useful to predict pCR were total neutrophil count ( CONCLUSIONS: The absolute neutrophil count better predicts pCR than the rest of inflammatory indexes in selected patients with LARC who underwent long-cycle NCRT. The association of a neutrophil count less than 6400 cells/mm3, absence of diabetes and intravenous 5-FU NCRT strategy showed a relevant increase of the pCR.