Correlation of interleukin-6 and C-reactive protein levels in plasma with the stage and differentiation of colorectal cancer: A cross-sectional study in East Indonesia

Abstract Introduction Tumors most often develop due to inflammatory factors, including inflammatory cells that produce cytokines and cytotoxic mediators that can stimulate malignant transformation. Knowing that interleukin-6 (IL-6) and C-reactive protein (CRP) factor into the development of colorectal cancer (CRC), we aimed to assess IL-6 and CRP's relationship with the stage and differentiation of CRC. Methods In a sample of 46 patients with CRC, as confirmed by histopathological examination, plasma levels of IL-6 and CRP were measured from peripheral venous blood samples before surgery and examined using enzyme-linked immunosorbent assay. Results Most patients were male (63.0%) and at least 50 years old (73.9%). A positive correlation emerged between stage of CRC and both plasma IL-6 (r = 0.396, p = .003) and CRP (r = 0.376, p = .005) levels, which the Kruskal–Wallis test indicated were highest in stage IV (IL-6: median = 25.80, p = .019; CRP: median = 34.10, p = .040). Plasma IL-6 levels (median = 25.80, p = .019) were higher in well-differentiated CRC, whereas plasma CRP levels (median = 34.10, p = .040] were higher in poorly differentiated tissue. Linear plotting revealed a linear relationship between plasma IL-6 and plasma CRP levels in patients with CRC. Conclusion Because the stage of CRC significantly correlates with plasma IL-6 and CRP levels, IL-6 and CRP can serve as diagnostic factors in assessing the progress and prognosis of CRC.