The Relationship Between Monocytic CD66b+ Levels and Disease Stage in Gastrointestinal System Cancers

Background and Objectives: TNM staging is one of the most important prognostic factors in gastrointestinal system cancers. It has been demonstrated that an inflammatory condition develops due to the tumor’s microenvironment in gastrointestinal system cancers. Myeloid-derived cells play a key role in this inflammation. Some of these myeloid derived cells are monocytic cells that express CD66b+ on their surfaces. CD66b+ monocytes were defined as a novel cell subpopulation that is isolated from the peripheral blood of cancer patients. The aim of this study was to investigate the relationship between monocytic CD66b+ levels and disease stage in gastrointestinal system cancers. Materials and Methods: Monocyte CD66b+ levels were measured by collecting peripheral venous blood samples in EDTA tubes from 50 gastric, colorectal, and pancreatic adenocarcinoma patients. The normality of the distributions of numeric variables was analyzed using “Shapiro-Wilk” test, and “Mann-Whitney U” test was used to analyze difference in median and min-max values, and “Spearman’s correlation” test was used for the correlation analyses. Results: A strong positive correlation was found between monocytic CD66b+ levels and disease stage in gastrointestinal system cancers (p<.001). As the disease stage advanced, monocytic CD66b+ levels were found to increase at a statistically significant rate. Conclusion: While whether elevated monocytic CD66b+ levels are a cause or effect in advanced-stage disease is unknown, increased monocytic CD66b+ levels are in parallel with the progression of disease stage. In light of these results, future studies should investigate whether monocytic CD66b+ levels are associated with prognosis and survival in gastrointestinal system cancers.