CCL2: A Pro-Inflammatory Driver and Candidate Diagnostic Biomarker in Colorectal Cancer Patients

Chronic inflammation and immune remodeling are key features of colorectal cancer (CRC) development and progression, particularly because of the high level of microbiome presence. Among inflammatory mediators, CCL2 has been implicated in the recruitment of monocytes and tumor-associated macrophages, supporting its potential role as a marker of CRC-associated inflammatory remodeling. Therefore, we evaluated nine circulating inflammatory mediators, including CCL2, to assess their potential diagnostic value in patients with CRC. The study included 96 individuals, comprising 52 CRC patients and 44 healthy controls. Plasma cytokine levels were measured using the ProteinSimple Ella microfluidic immunoassay platform, and analyses were also stratified according to sex and BMI category (BMI < 25 vs. ≥25 kg/m2). Patients with CRC had significantly higher levels of CCL2 and IL-6 than healthy controls (p-value < 0.001), regardless of gender or overweight or obesity, confirming a chronic pro-tumor inflammatory profile. Among all markers, CCL2 showed strong exploratory diagnostic performance with an AUC of 0.918, 90.4% sensitivity, and 90.9% specificity (cut-off 436.5 pg/mL). This study highlights the central role of CCL2 as a candidate marker of systemic chronic inflammation associated with colorectal cancer.