Myeloid-derived suppressor-like cells - a potential biomarker for prognosis of colorectal cancer?

Abstract

Background/Aim. Myeloid-derived suppressor cells (MDSC) represent a heterogeneous group of immature cells of myeloid origin, which have the ability to inhibit both the innate and adaptive immune response. Due to its immunosuppressive effect, MDSC can promote the growth and progression of cancer. Colorectal cancer (CRC) is one of the most common cancers in the general population for whose advanced stages of the disease there is still no good therapy. In addition to contributing to the development and spread of CRC, MDSC could potentially be markers of its prognosis. The aim of the study was to examine the potential prognostic role of peripheral blood MDSC counts in CRC patients. Methods. In a prospective study we analyzed the possibility of using CD16low granulocytes and mononuclear (M-MDSC) like cells as well as neutrophyl to lymphocyte ratio (NLR), lymphocite to monocyte ratio (LMR), CD16hi/CD16low granulocytes ratio and M/MMDSC like cells ratios before starting of the treatment as a biomarker for overall survival (OS) in patients with CRC. Hazards ratios (HRs) with the corresponding 95% confidence intervals (95%CIs) were calculated to evaluate the prognostic role of MDSCs in cancer. Results. The analysis was performed in 47 patients in stage III and IV CRC according to the TNM/AJCC disease classification. Dependable data were obtained in 32 patients. Patients blood samples are taken before the possible start of treatment (surgery, chemotherapy). Increased percentage and absolute values of CD16low granulocytes as well as absolute values of M-MDSC-like cells have been shown to be associated with shorter overall survival (OS) (p < 0.0066, p < 0.0013 and p < 0.0119, respectively). The relationship of CD16hi/CD16low granulocytes ratio and M/M-MDSC like cells ratio with OS indicated the existence of positive correlations between these parameters, which higher value of this relationship indicated longer survival of patients (p < 0.0054 and p < 0.0426, respectively). Relationship between OS and NLR indicators found statistically significant inverse correlation with NLR (p = 0.0349). No statistical significance was found in the relationship between OS and LMR. Conclusion. This study shows that percent and absolute numbers of CD16low granulocytes, as well as absolute number of M-MDSC like cells, CD16hi/CD16low granulocytes ratio, M/M-MDSC like cells and NLR ratio ratio may be reliable indicators of survival in patients with CRC.