The role of interleukins and immunological parameters in patients with colon cancer: an optical insight

The progression of colon cancer from benign adenoma to malignant tumors that invade and spread underscores the critical need for accurate and less invasive biomarkers. The primary objective of this work was to assess the diagnostic potential of combining immunological biomarkers and optical polarimetric characteristics in colorectal cancer. We specifically aimed to evaluate serum cytokine profiles as potential diagnostic tools and to explore tissue optical signatures in a preliminary analysis. Secondary objectives included examining postoperative immune changes and exploring the involvement of immune checkpoints in cancer progression. Serum levels of IL-8, IL-17 A, IL-37, CTLA-4, and CCR7 were measured using ELISA in 75 colon cancer patients (37 preoperative and 38 postoperative) and 15 healthy controls, whereas tissue properties were analyzed through Mueller matrix polarimetry. Compared with healthy controls, preoperative patients had significantly higher levels of IL-8, IL-17 A, CTLA-4, and CCR7 and lower levels of IL-37 (all P < 0.001), and all five markers discriminated preoperative patients from controls in ROC analysis (AUC 0.939-1.000). Postoperative patients showed intermediate levels, consistent with partial normalization of these markers after surgery. In a preliminary polarimetric analysis of a limited number of tissue sections, cancerous tissue showed higher total depolarization than normal tissue, whereas total retardance and diattenuation varied widely and overlapped between the two tissue types. These findings support serum cytokine and immune-checkpoint profiling as a promising, less invasive approach for colorectal cancer detection and monitoring, whereas the diagnostic value of Mueller matrix polarimetry needs to be confirmed in a larger number of tissue samples with formal statistical evaluation.