Background: In recent years, measurement of the trace elements in human serum has been used for cancer diagnosis. The purpose of this study was to compare the serum concentrations of Cu, Zn and Cu /Zn ratio of colorectal cancer (CRC) patients with those of healthy subjects.

Materials and Methods: This study was conducted on 130 patients with CRC (57 women and 73 men) and 128 health subjects (65 women and 63 men). Flame atomic absorption spectroscopy method was used to analyze the serum trace element concentrations.

Results: The results showed that the serum Cu levels were significantly lower (P<0.01) in patients with CRC than the healthy controls, but no significant difference was observed between serum concentration of zinc in patients and healthy subjects. The concentrations of Zn in patients and healthy subjects were (68.38±44.76 vs. 142±37.61 ug/dl) and (84±53.51 vs. 140.37±63.43), respectively, in female and male subjects. Serum concentrations of Cu were (139±139.92 vs. 160.44±46.38 ug/dl) and (123.50±77.76 vs. 160.93±44.15 ug/dl), respectively, in female and male subjects. However, the Cu/Zn ratio increased significantly in both male (2.64±2.98 vs. 1.42± 0.88) and female (3.02±3.90 vs. 1.22±0.60) subjects.

Conclusion: The serum copper levels and the Cu/Zn ratio may have an instrumental role in CRC development or can be used as a prognosis marker.