Jl. Poo et al., DIAGNOSTIC-VALUE OF THE COPPER ZINC RATIO IN DIGESTIVE CANCER - A CASE-CONTROL STUDY/, Archives of medical research, 28(2), 1997, pp. 259-263
The aim of this study was to assess the accuracy of the copper/zinc ra
tio (Cu/Zn ratio) in the evaluation of a large group of patients with
digestive cancer compared to gender and age-matched central subjects.
A total of 282 patients was studied and separated into three groups: g
roup I (n = 75), patients with digestive cancer, group II (n = 112), p
atients with benign digestive disease, and group III (n = 95), healthy
subjects. Serum levels of copper and zinc were measured by atomic abs
orption spectrophotometry. The results showed that the serum levels of
copper (mg/dL) in patients with digestive cancer (91.6 +/- 27.3, p <
0.05) were significantly higher than in patients with benign digestive
disease (75.8 +/- 19.8) or healthy subjects (54.4 +/- 8.9) and the se
rum levels of zinc (mg/dl) were significantly lower (68.7 +/- 21.9, p
< 0.05) compared to benign digestive disease patients (80.1 +/- 18.7)
or healthy subjects (100 +/- 11.4 mg/dl). The Cu/Zn ratio was also sig
nificantly higher in patients with digestive cancer (1.45 +/- .58, p <
0.05) than those with benign digestive disease (0.95 +/- 0.28) or hea
lthy subjects (0.55 +/- 0.13). Considering a cutoff value of 0.87, the
sensitivity of the copper/zinc ratio was 82.2%, with a specificity of
65.7%, a positive predictive value of 45.8% and a negative predictive
value of 91.3%. In conclusion, Cu/Zn ratio was found to be considerab
ly higher in patients with digestive cancer compared to age- and gende
r-matched controls, with a sensitivity of 82.2% that might be useful i
n the evaluation of suspected malignancy.