Comparison of Hematologic and Other Prognostic Markers in Metastatic Colorectal Cancer

Associations of thrombocytosis, neutrophilia, and lymphopenia with prognosis have been confirmed in many cancers. This study aims at comparing various prognostic indices based on blood counts in metastatic colorectal adenocarcinomas.

Records from 152 patients with metastatic colorectal cancer who were treated in our center were reviewed. Demographic and disease characteristics and hematologic parameters data were extracted and patients were stratified according to their scores of several hematologic ratios. Hematologic ratios and parameters considered included the platelet-neutrophil to lymphocyte ratio (PNLR), the platelet to lymphocyte ratio (PLR), the neutrophil to lymphocyte ratio (NLR), the Abnormal Hematological Markers Index (AHMI), and the neutrophil-platelet score (NPS). Optimal cutoffs were defined with the aid of an online tool. Baseline parameters of the two groups derived for each tool were evaluated and compared with the χ² test. Univariate and multivariate Cox proportional-hazards regression analyses were performed on variables of interest.

Progression-Free Survival (PFS) hazard ratios (HR) between the high-risk and low-risk groups derived from the multivariate analyses for each index were as follows: for PNLR 2.0 (95% CI 1.28-3.13), for PLR 1.74 (95% CI 1.13-2.67), for NLR 1.54 (95% CI 1.04-2.29), for AHMI 1.62 (95% CI 1.06-2.46), and for NPS 1.47 (95% CI 1.1-1.96). Overall Survival (OS) hazard ratios (HR) derived from the multivariate analyses for each index were as follows: for PNLR 2.23 (95% CI 1.36-3.66), for PLR 1.68 (95% CI 1.03-2.75), for NLR 1.62 (95% CI 1.06-2.49), for AHMI 1.7 (95% CI 1.07-2.69), and for NPS 1.53 (95% CI 1.11-2.11). Another prognostic index called PRONOPALL, which is based on ECOG PS (0-1 versus 2-3 versus 4), number of metastatic sites (≤ 1 versus ≥ 2), LDH (< 600 U/L versus ≥ 600 U/L), and albumin (≥ 33 g/L versus < 33 g/L), had HRs of 1.75 and 2.20 for PFS and OS, respectively, with a cutoff of < 4 versus ≥ 4. This score has a range of 0 to 10 and points are attributed for the presence of each of the four prognostic factors.

In this analysis of metastatic colorectal cancer patients, several ratios and other prognostic tools had prognostic value for both OS and PFS. While other variables held significance for poorer prognosis, PNLR had the highest HR and the highest significance in multivariate analysis for both PFS and OS. Thus, it represents a valid prognostic tool in metastatic colorectal cancer among the spectrum of hematologic parameter-constructed tools.