682 Background: The magnitude of the systemic inflammatory response before and after surgery for rectal cancer is increasingly understood to have an impact on clinical outcomes. The aim of the present study was to examine the impact of neoadjuvant chemoradiotherapy (nCRT) on pre- and postoperative systemic inflammation and clinical outcomes in patients undergoing surgery for rectal cancer. Methods: Data was recorded prospectively for patients who underwent elective, potentially curative surgery for rectal cancer, from 2008 to 2015 at a single centre, n = 251. Patients had routine pre- and postoperative blood sampling. Results: Of the 251 patients, the majority were male (62%) and over 65 years old (57%) with node negative disease (66%). 85 patients (33%) were allocated to preoperative nCRT based on probable margin threatening disease at preoperative MRI. nCRT was significantly associated with a higher proportion of patients having neutrophil lymphocyte ratio (NLR) > 5 (39% vs. 12%, p < 0.001), and a modified Glasgow Prognostic Score (mGPS) of 2 (14% vs. 6%, p = 0.035) prior to surgery. There was no significant association between nCRT and the magnitude of the postoperative systemic inflammatory response or complications. Of the 85 patients who underwent nCRT, there was a small but significant reduction in CRP following treatment (3.25 mg/L vs. 4.1 mg/L, p = 0.007). Of the 16 patients who were systemically inflamed prior to nCRT, 9 patients achieved mGPS score 0 after treatment (p = 0.004). There was a significant association between having an mGPS score 1 or 2 both before and after nCRT and breaching established thresholds of CRP on postoperative days 2 (190mg/L, 86% vs. 33%, p = 0.002), 3 (170mg/L, 86% vs. 38%, p = 0.015) and 4 (145mg/L, 71% vs. 36%, p = 0.031). Conclusions: Allocation to nCRT was significantly associated with a systemic inflammatory response prior to surgery for rectal cancer. nCRT was significantly associated with attenuation of existing systemic inflammation. Such attenuation of the systemic inflammatory response may in part explain the efficacy of nCRT in patients with rectal cancer.
Systemic Inflammatory Response After Preoperative Chemoradiotherapy Can Affect Oncologic Outcomes in Locally Advanced Rectal Cancer
