Abstract
The usefulness of the serum Cu/Zn ratio as a tumor marker for lung cancer was evaluated. Abnormally elevated levels of the ratio were detected in 58% of the patients with lung cancer. The mean value of serum Cu/Zn ratio was significantly higher in the patients with lung cancer than in the healthy controls, but the difference between the patients with lung cancer and patients with nonmalignant pulmonary diseases was not statistically significant. The serum Cu/Zn ratio was significantly higher in patients with an advanced stage of lung cancer than in patients with early stage of lung cancer. However, the receiver operating characteristic curve of serum Cu/Zn ratio for discriminating lung cancer from nonmalignant pulmonary diseases, was very similar to that of C-reactive protein. These observations indicate that although the serum Cu/Zn ratio is not a tumor specific marker for lung cancer, it may be a useful stage marker for patients with inflammatory and consumptive disorders such as lung cancer.
