Neutrophil-lymphocyte ratio predicts pathologic tumor response and survival after preoperative chemoradiation for rectal cancer

BACKGROUND: Neutrophil-lymphocyte ratio (NLR) reflects the balance between pro- and anti-tumor immune activities. We evaluated whether NLR is associated with pathologic tumor response and prognosis in rectal cancer patients that underwent preoperative chemoradiaton therapy (CRT) with surgery. METHODS: One hundred two patients with rectal cancer that were treated by preoperative CRT followed by surgery were enrolled. A total of 50.4 GY of radiation and 5-FU-based chemotherapy were delivered. An NLR ≥ 3 was considered to be elevated. Pathologic tumor response based on ypTNM stage was categorized into two groups, good response (n = 35, pathologic complete response and ypTNM I) and poor response groups (n = 67, ypTNM II, III, and IV). RESULTS: Twenty-five patients (24.5%) had elevated NLR. Multivariate analysis showed that an elevated CEA level (p = 0.001), larger tumor (p = 0.03), and elevated NLR (p = 0.04) were significant predictors for a poor response. Poor pathological tumor response and elevated NLR were risk factors for cancer-specific and recurrence-free survivals. CONCLUSION: An elevated NLR before CRT can be used as predictors for poor tumor response and unfavorable prognostic factors. Dominant pro-tumor activities of neutrophils or reduced anti-tumor immune response by lymphocytes, as determined by NLR, may have a impact on poor tumor response and unfavorable prognosis. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2482-14-94) contains supplementary material, which is available to authorized users.