Circulating tumor cells and neutrophil-lymphocyte ratio are predictive markers for metastatic colorectal cancer patients

Background: More accurate predictive factors for colorectal cancer (CRC) are urgently needed. This study aimed to assess the potential prognostic roles of circulating tumor cells (CTCs), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR) in CRC patients. Methods: Between 2014 and 2017, 118 CRC patients newly diagnosed at the Affiliated Zhongshan Hospital of Dalian University were retrospectively analyzed, including 72 (61%) patients that underwent radical resection (resectable CRC) and 46 (39%) advanced patients with metastatic CRC (mCRC). The CellSearch System was used to detect CTCs, and Spearman's correlation analyses tested the correlations between CTC counts and both NLR and PLR. Statistical analyses were performed using the Kaplan-Meier method, log-rank tests, and Cox proportional hazards models. Results: Of the resectable cohort, 24% were positive for CTCs. Of the advanced cohort, 49% were positive for CTCs. The presence of CTCs was associated with advanced age (63 years old; P=0.037), a high PLR value (P=0AX/8), and a high NLR value (P=0.034). Additionally, baseline NLR [hazard ratio (HR) =0.423; 95% confidence intervals (CI), 0.223-0.803; P=0.008], PLR (HR =0.513; 95% CI, 0.276-0.954; P=0.035), and CTC counts (HR =2.155; 95% CI, 1.152-4.032; P=0.016) were significantly associated with progression-free survival (PFS) in a univariate analysis of mCRC patients that received chemotherapy. Multivariate analysis further showed that NLR (P=0.044) and CTCs (P=0.047) were independent prognostic factors for mCRC patients. Conclusions: This study provided evidence that NLR and CTC counts could serve as robust prognostic factors for patients with mCRC.