RESUMO
The aim of this study was to assess the accuracy of the copper/zinc ratio (Cu/Zn ratio) in the evaluation of a large group of patients with digestive cancer compared to gender and age-matched control subjects. A total of 282 patients was studied and separated into three groups: group I (n=75), patients with digestive cancer, group II (n=112), patients with bening digestive disease, and group II (n=95), healthy subject. Serum levels of copper and zinc were measured by atomic absorption spectrophotometry. The results showed that the serum levels of copper (mg/dL) in patients with digestive cancer (91.6 ñ27.3, p<0.05) were significantly higher than in patients with benign digestive diseasde (75.8 ñ 19.8) or healthy subjects (54.4 ñ 8.9) and the serum levels of zinc (mg/dl) were significantly lower (68.7 ñ 21.9, p<0.05) compared to benign digestive disease patients (80.1 ñ 18.7) or healthy subjects (100 ñ 11.4 mg/dl). The Cu/Zn ratio was also significantly higher in patients with digestive cancer (1.45 ñ .58, p<0.05) than those with benign digestive disease (0.95 ñ 0.28) or healthy subjects (0.55 ñ 0.13). Considering a cutoff value of 0.87, the sensitivity of the copper/zinc ratio was 82.2 percent, with a specificity of 65.7 percent, a positive predictive value of 45.8 percent and a negative predictive value of 91.3 percent. In conclusion, Cu/Zn ratio was found to be considerably higher in patients with digestive cancer compared to age-and gender-matched controls, with a sensitivity of 82.2 percent that might be useful in the evaluation of suspected malignancy