Correlations between 13 Trace Elements and Circulating Tumor Cells in Patients with Colorectal Cancer in Guangzhou, China

We established a method of determining 13 trace elements (TEs) in whole blood, determined the levels of the TEs in patients with colorectal cancer (CRC), and examined the correlations between the TEs and circulating tumor cells (CTCs). A total of 93 CRC patients and 48 control subjects in Guangzhou, China, were included. Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure the blood levels of 13 TEs. CTCs of 13 CRC patients were examined using CanPatrol™. The levels of Mg, Fe, Zn, Se, Sr, Mo, and Ba in CRC patients were lower than those in control subjects (all, P  < 0.05). The levels of Mg, Fe, Zn, Se, and Ba decreased with increasing TNM stage. The reductions of Zn and Se levels were higher in early-stage than late-stage CRC patients. The levels of Cu and Ni were higher in CRC patients than in control subjects (both, P  < 0.05). The Cu level increased with increased TNM stage, and Ni level was higher in early-stage CRC patients as compared with late-stage CRC patients. Consequently, the TE levels showed differences as the process of TNM stage of CRC patients. There were correlations between the amount of CTCs and epithelial-CTCs (E-CTCs) and interstitial-CTCs (M-CTCs) ( P  < 0.05). The levels of Mg, Cr, Fe, Cu, Zn, Se, Sr, and Ba were correlated with the number of CTCs ( P  < 0.05). Specific TE patterns in whole blood may assist in the early diagnosis of CRC. The combined determination of TE levels and CTCs may be useful as an adjunct to staging and guiding treatments.