Selenium, Zinc, and Plasma Total Antioxidant Status and the Risk of Colorectal Adenoma and Cancer

Abstract

Selenium (Se), zinc (Zn), and copper (Cu) are known to be involved in carcinogenesis and participate in the defence against reactive oxygen species (ROS). This study aimed to evaluate the clinical utility of serum Se, Zn, and Cu concentrations and plasma total antioxidant status (TAS) in the diagnosis of colorectal cancer (CRC) and colorectal adenoma (CRA) in a population of low Se and borderline Zn status. Based on clinical examination and colonoscopy/histopathology, the patients (n = 79) were divided into three groups: colorectal cancer (n = 30), colorectal adenoma (n = 19), and controls (CONTROL, n = 30). The serum Se concentration was lower in the CRC group than in the CRA group (by 9.1%, p < 0.0001) and the CONTROL group (by 7.9%, p < 0.0001). In turn, the serum Zn concentration was decreased in the CRA group (by 17.9%, p = 0.019) when compared to the CONTROL group. Plasma TAS was lower in the CRC group (by 27.8%, p = 0.017) than in the CONTROL group. In turn, the serum Zn concentration was decreased in the CRA group when compared to the CONTROL group. Plasma TAS was lower in the CRC group than in the CONTROL group. ROC (receiver operating characteristic) curve analysis revealed that the Se level was of the highest diagnostic utility for the discrimination of the CRC group from both the CRA group (area under ROC curve (AUC) 0.958, sensitivity 84.21%, specificity 100%) and the CONTROL group (AUC 0.873, sensitivity 100%, specificity 66.67%). The Zn and TAS levels were significantly accurate in the differentiation between the groups. An individualised risk of colorectal adenoma and cancer approach could comprise Se, Zn, and TAS assays in the population.

Keywords: colorectal adenoma; colorectal cancer; copper; plasma antioxidant status; selenium; zinc.

Figure 8

Molecular and cellular influence of lower levels of selenium and selenium-containing compound families: glutathione peroxidases, selenoprotein P, and lower levels of zinc and zinc-containing compound families: metalloenzymes, including cytoplasmic enzymes (for instance, superoxide dismutase and phosphodiesterase), mitochondrial enzymes (such as cytochrome oxidase and pyruvate carboxylase), nuclear enzymes like DNA and RNA polymerases on colorectal polyps (adenoma, CRA) and colorectal cancer (CRC) development; ROS—reactive oxygen species; TAS—total antioxidant status; authors’ own compilation based on [3,5,6,16,17,18,19,20,21,22,53,54,55,56,57,58,60,61,65,66,67,68,69,77,78,79,80,81].

Figure 1

(A) The endoscopy image with the colorectal adenoma (CRA); (B) The endoscopy image with the colorectal cancer (CRC).

Figure 2

Histogram of the serum selenium concentrations in the colorectal cancer patients (CRC) and the colorectal adenoma group (CRA).

Figure 3

Histogram of the serum selenium concentrations in the colorectal cancer patients (CRC) and the control group (CONTROL).

Figure 4

Histogram of the serum zinc concentrations in the colorectal adenoma patients (CRA) and the control group (CONTROL).

Figure 5

Receiver operating characteristic (ROC) curves for selenium (Se) level (square), total antioxidant status (triangle), and zinc (Zn) level (circle) in the differentiation between colorectal cancer patients (CRC) and the control group (CONTROL). Selenium: cut-off value ≤ 69.3 µg/L, sensitivity 100%, specificity 66.67%, AUC 0.873, 95%CI: 0.761–0.945, p < 0.0001; Total antioxidant status: cut-off value > 1.15 mmol/L, sensitivity 93.33%, specificity 53.33%, AUC 0.718, 95%CI: 0.587–0.827, p = 0.002; Zinc: cut-off value > 13.01 µmol/L, sensitivity 73.33%, specificity 56.67%, AUC 0.652, 95%CI: 0.518–0.771, p = 0.032; AUC—area under the ROC curve.

Figure 6

Receiver operating characteristic (ROC) curves for selenium (Se) level (square) and total antioxidant status (circle) in the differentiation between groups: colorectal cancer (CRC) and colorectal adenoma (CRA). Selenium: cut-off value > 69.3 µg/L, sensitivity 84.21%, specificity 100%, AUC 0.958, 95%CI: 0.858–0.995, p < 0.0001; Total antioxidant status: cut-off value > 1.19 mmol/L, sensitivity 84.21%, specificity 56.67%, AUC 0.679, 95%CI: 0.530–0.805, p = 0.024; AUC—area under the ROC curve.

Figure 7

Receiver operating characteristic (ROC) curves for zinc concentration in the differentiation of colorectal adenoma patients (CRA) from the control group (CONTROL); Zinc: cut-off value > 11.62 µmol/L, sensitivity 96.67%, specificity 52.63%, AUC 0.730, 95%CI: 0.584–0.847, p = 0.003; AUC—area under an ROC curve.