Screening of prognosis-related Immune cells and prognostic predictors in Colorectal Cancer Patients.

Objective: To accurately screen potential immune cells that can predict the survival of colorectal cancer (CRC) patients and identify related prognostic predictors.

Methods: The sample data of CRC patients were downloaded from the GEO database as a training set to establish a prognosis-scoring model and screen prognosis-related immune cells. The sample data of CRC patients from the TCGA database were used as the validation set. Simultaneously, cancer tissue samples from 116 patients with CRC diagnosed pathologically in Shanghai Dongfang Hospital were collected to analyze the relationship of prognosis-related immune cells with patients' survival, and clinical and pathological parameters, and to screen prognostic predictors.

Results: Prognosis-related immune cells screened from GEO and TCGA databases mainly included Follicular Helper T cells (Tfh), Monocytes and M2 Macrophages. In the training set, the 2,000- and 4,000-day survival rates were 48.3% and 10.7% in the low-risk group (N = 234), and 42.1% and 7.5% in the high-risk group (N = 214), respectively. In the validation set, the 2,000- and 4,000-day survival rates were 34.8% and 8.6% in the low-risk group (N = 187), and 28.9% and 6.1% in the high-risk group (N = 246), respectively. The prognosis of patients in the high-risk group was worse than that in the low-risk group (P < 0.05). Furthermore, the screened primary prognostic predictors were CD163 and CD4 + CXCR5. CD163 protein expression was distributed in Monocytes and M2 Macrophages. The 1,000- and 2,000-day survival rates were 56.1% and 7.0% in the CD163 low-expression group, and 40.7% and 1.7% in the high-expression group (N = 214), respectively, showing a worse prognosis in the high-expression group than that in the low-expression group. Meanwhile, the immune marker CD4 + CXCR5 could identify Tfh. The 1,000- and 2,000-day survival rates were 63.9% and 5.6% in the CD4 + CXCR5 high-expression group, and 33.3% and 2.8% in the low-expression group (N = 214), respectively, with a better prognosis in the high-expression group than that in the low-expression group.

Conclusion: Prognostic-related immune cells of CRC mainly include Tfh cells, Monocytes and M2 Macrophages. Monocytes and M2 Macrophages correlate negatively, while Tfh cells correlate positively with the prognosis of CRC patients. Immune markers CD163 and CD4 + CXCR5 can be considered as the prognostic predictors of CRC with clinical value of the application.