A stromal and immune cell infiltration-based score model predicts prognosis and chemotherapy effect in colorectal cancer.

The stromal and immune cells crosstalk with cancer cells in tumor microenvironment, but few studies have fully considered the overall landscape of the infiltrating stromal and immune cells in colorectal cancer. We enrolled 1836 colorectal cancer patients and divided them into the training, validation and test cohorts. 64 stromal and immune cells were quantified in each primary colorectal cancer tissue by estimating gene expression data using xCell algorithm. Univariate, LASSO and multivariate Cox regression analyses were subsequently employed to establish a stromal and immune score prognostic model based on 13 potential cell biomarkers. Patients of the three cohorts were divided into the high- and low-risk groups according to the cutoff value. Compared with the low-risk group, high-risk group showed significant shorter survival, worse clinicopathologic outcomings, higher cancer-related expressions and more active epithelial-mesenchymal transformation. 5-Fu and FUFOL chemotherapy regimens made the low-risk patients gain significant survival advantage, while none chemotherapy regimens benefited the high-risk group, which may benefit from immune checkpoint inhibitors. The nomogram combining the stromal and immune score with standard TNM staging system showed better predictive accuracy than TNM stage alone. The stromal and immune cell infiltration-based score model can effectively and efficiently predict the prognosis and chemotherapy effect in colorectal cancer.