INFLAMMATORY MARKERS AS PREDICTORS OF RECURRENCE OF COLORECTAL CANCER. LITERATURE REVIEW

The urgent requirement for biological markers capable of indicating a high risk of recurrence persists for colorectal cancer (CRC) patients. The aim of the study is to evaluate the prognostic value of inflammatory markers (IM) as disease course predictors for CRC patients based on the results of scientific research on this topic. The search of literature sources on the selected topic was performed in the Web of Science, Scopus and Pubmed databases. Keywords for the search were: "inflammatory markers", "colorectal cancer", "survival", "prognosis", "neutrophils", "lymphocytes", "monocytes", "platelets", "albumin", "C-reactive protein". Even though the design of the reviewed studies was different by the quantitative and qualitative composition of the cohorts and time points for marker determination, it was possible to single out the most frequently used IM and their main characteristics. The neutrophils-to-lymphocytes ratio (NLR) was found to be one of the most common markers. Patients with high NLR showed worse recurrence-free and overall survival. Most of the works devoted to this IM assess its level for predicting the course of CRC after radical surgery. In contrast to NLR, patients with a high lymphocyte-to-monocyte ratio (LMR) had better overall survival. In addition, the researchers established a relationship between the level of this marker and the grade of tumor differentiation. The Systemic Inflammatory Score (SIS) reflects the combined prognostic value of LMR and albumin. Its high levels are associated with worse prognosis. High levels of PLR (platelet-to-lymphocyte ratio) and PNLR (platelet-to-neutrophil-to-lymphocyte ratio), or as it is also called systemic inflammatory index (SII), are independent predictors of poor prognosis. Classic and modified Glasgow scales (GPS and mGPS) are used for predicting the course of the disease, both in the postoperative period and for metastatic cancer. As well as the scales, the PNI marker (prognostic nutritional index) is associated with the albumin level. The decrease in its level is associated with poor prognosis. A particular focus was given to the novel marker, "LA", which was used for patients with rectal cancer. Its high levels, in contrast to PNI, proved to be a predictor of a good prognosis. The prognostic inflammatory index (IPI) proved to be a statistically better predictor of relapse than the mGPS described above. And the ALI (Inflammatory Index of Advanced Lung Cancer), low values of which indicate poor overall survival, was found to be more sensitive than the IPI. Unfavorable prognosis is also associated with low levels of the albumin-globulin ratio (AGR). High CAR levels (CRP-albumin ratio) and low LCR levels (lymphocyte-CRP ratio) are associated with shorter recurrence-free and overall survival. The results of the performed scientific search made it possible to establish a statistically significant prognostic value of IM as disease course predictors for CRC patients. The absolute advantage of IM is their accessibility, as the majority of indicators are determined in routine practice. Additionally, it offers ease of use as its calculation based on simple mathematical formulas. Cut-off values for each marker may differ depending on the stage of the disease in the studied cohort, the time points of determining the value of the marker, use of therapy. There might be a dependence on other parameters that have not yet been investigated.