Differences in circulating lymphocyte subpopulations among patients with inflammatory polyps, colorectal adenomas and colorectal cancer

Abstract

Background and Study Aims

Colorectal cancer (CRC) may develop from focal changes within benign or precancerous polyps. The immune system’s failure to detect and eradicate tumor cells due to immune surveillance evasion, allows cancer to develop and spread. This study aims to analyze the differences in circulating lymphocyte subpopulations in patients with colorectal inflammatory polyps, colorectal adenomas and CRC.

Patients and Methods

We retrospectively reviewed patients from September 2016 to December 2019 at the Shaoxing Second Hospital. Using flow cytometry, the subset distribution and immunophenotype of T cells, CD4⁺ T cells, CD8⁺ T cells, B cells and NK cells were investigated in peripheral blood mononuclear cell samples. The counts of lymphocytes were determined by white blood cell counts.

Results

In total, 518 patients were included in this study. The counts of lymphocytes, T cells and NK cells in patients with inflammatory polyps, colorectal adenomas and CRC were lower than controls. The counts and percentages of CD8⁺ T cells in patients with inflammatory polyps, colorectal adenomas and CRC were lower than controls. The counts of CD4⁺ T cells were lower in patients with CRC than inflammatory polyps. The percentages of CD4⁺ T cells in patients with inflammatory polyps, colorectal adenomas and CRC were higher than controls, but lower in the CRC than inflammatory polyps, colorectal adenomas. The counts and percentages of B cells were lower in CRC patients than colorectal adenomas patients. In addition, the percentages of B cells were higher in patients with inflammatory polyps and colorectal adenomas than in controls.

Conclusions

The decrease in counts of lymphocyte, T cells, CD8⁺ T cells and NK cells in patients may be related to the dysplasia of epithelial cells. Furthermore, the B cells and CD4⁺ T cells may be related to the malignant growth of the dysplastic epithelial cells.