- Chronic inflammation has been linked with many cancers. It seems that easily available and usual blood inflammatory markers might serve as a prognostic factor for overall survival and disease-free survival in patients with various cancers. Preoperative neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), as well as hemoglobinemia, thrombocytosis, elevated C-reactive protein values, neutropenia and leukocytosis have been shown to affect overall survival and disease-free survival in patients with colorectal cancer (CRC), however, with controversial results. Complete blood count, NLR and PLR were determined in 71 patients with CRC (stages 3 and 4) after neoadjuvant chemo-radiotherapy and before surgery, treated at Hospital for Tumors in Zagreb. Statistical analysis included Mann-Whitney U test, Student's t-test, univariate and multivariate analysis. The results of Mann-Whitney U test and Student's t-test showed that neutrophil count (p=0.024), NLR (p=0.003) and PLR (p=0.007) correlated significantly with overall survival. However, there was no significant correlation of age, leukocyte, lymphocyte and platelet counts and hemoglobin values with overall survival of patients. Furthermore, the same tests showed that leukocyte (p=0.04), neutrophil (p=0.0014) and platelet (p=0.006) counts, NLR (p=0.0006) and PLR (p=0.0015), as well as hemoglobin values (p=0.028) correlated significantly with disease-free survival. The results of univariate analysis showed that unlike PLR, NLR correlated with overall survival and disease-free survival (p=0.0002), although the correlation of PLR and disease-free survival almost reached significance (p=0.059). Furthermore, the results of univariate analysis showed significant correlation of advanced pathological TNM stage with overall survival. There was no correlation of patient age and gender, tumor stage and neoadjuvant chemo-radiotherapy with overall survival and disease-free survival. The results of multivariate analysis showed that NLR (cut-off value 3.27) and advanced pathological TNM stage significantly correlated with disease-free survival but not with overall survival. It seems that NLR might be an accurate marker for overall survival and disease-free survival in CRC patients after neoadjuvant chemo-radiotherapy and before surgery.
Keywords: Blood cell count; C-reactive protein; Colorectal neoplasms; Disease-free survival; Inflammation.