MO1-1 Lymphocyte-C-reactive protein ratio as a prognostic marker in rectal cancer patients with neoadjuvant chemoradiotherapy

Rectal cancer (RC) has a high frequency of local recurrence, and preoperative chemoradiotherapy (CRT) followed by total mesorectal excision (TME) is currently the recommended standard treatment strategy in patients with advanced RC. In contrast, the systemic inflammatory response is attracting increasing attention as a predictive biomarker for oncological outcome in patients with colorectal cancer (CRC). We recently developed the lymphocyte-C-reactive protein (CRP) ratio (LCR) as a new predictive biomarker for oncological outcome in CRC patients. This study aimed to verify if the LCR could be used as a predictor of oncological outcome in patients with RC receiving preoperative CRT. We analyzed data for 86 patients with RC who received preoperative CRT followed by TME at our institution. A ratio of 6000 was used as the cut-off value for LCR for further analysis. The post-CRT LCR was significantly lower than the pre-CRT LCR in patients with RC (p<0.0001). Although post-CRT LCR status was not significantly correlated with overall survival (OS), low pre-CRT LCR was significantly associated with shorter recurrence free survival (RFS: p=0.02) and OS (p=0.017) in this population, and was an independent prognostic factor for both RFS and OS (hazard ratio (HR): 3.19, 95% confidence interval (CI): 1.33-7.66, p=0.009, HR: 2.83, 95%CI: 1.14-7.01, p=0.025, respectively). Furthermore, low pre-CRT LCR was a stronger indicator of early recurrence (p=0.001) and poor prognosis (p=0.025) in RC patients without pathological lymph node metastasis compared with patients with pathological lymph node metastasis, and prognostic potential of pre-CRT LCR was clearly revealed especially RC patients receiving long-course CRT. Quantification of pretreatment LCR status using an optimal cut-off value could help physicians to make decisions regarding postoperative treatment strategies in RC patients undergoing CRT followed by potentially curative resection.