Relationship between nutritional indicators and clinicopathological factors, including immune cell densities in the tumor microenvironment, in patients with colorectal cancer.

We retrospectively analyzed 116 cases of colorectal cancer (CRC) to evaluate the relationship between nutritional indicators (NIs) and clinicopathological features, including immune cell infiltration in the tumor microenvironment. The geriatric nutritional risk index (GNRI), prognostic nutritional index (PNI), modified Glasgow prognostic score (mGPS), Controlling Nutritional Status (CONUT) score, and neutrophil-to-lymphocyte ratio (NLR) were assessed. Immune cell densities (CD3, CD8, Foxp3, Iba1, CD163) were quantified by immunohistochemistry. Poor NIs were associated with older age, lower body mass index, advanced tumor stage, elevated tumor markers, and reduced immune cell infiltration. Specifically, low GNRI and high mGPS correlated with reduced Foxp3-positive cells; low PNI with reduced Foxp3- and CD20-positive cells; and high NLR with reduced CD3-, CD8-, CD20-, and Iba1-positive cells. The GNRI- and mGPS-abnormal groups showed significantly reduced Foxp3-positive cells, and the CONUT-abnormal group exhibited decreased CD3- and CD20-positive cells. Patients with abnormal NLR had significantly worse cancer-specific survival. However, it was not identified as an independent prognostic factor in the multivariate analysis. Nutritional impairment in CRC patients is linked not only to poor clinical outcomes, but also to a tumor-promoting microenvironment characterized by diminished immune cell infiltration. Assessing NIs may help guide nutritional and therapeutic strategies to improve prognosis.