Serum copper (Cu), zinc (Zn) the Cu/Zn ratio (Cu/Zn) and selenium (Se) were evaluated in 84 patients with non-small cell lung cancer (NSCLC) before surgery. Serum carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC) and sialyl Lewis X-i antigen (SLX) levels were also determined in the same cases. The cut-off values of Cu, Zn and Se were established to create two categories with equal numbers of patients. We investigated the clinical and prognostic usefulness of assays of serum trace elements (Cu, Zn, Cu/Zn and Se) and compared levels of serum trace elements and serum tumor markers (CEA, SCC and SLX) in NSCLC patients. Furthermore, we evaluated the usefulness of serum trace elements, when compared with tumor markers, in assessing prognosis for NSCLC.
In conclusion: (1) a preoperative increase in Cu/Zn level predicted tumor progression more effectively than changes in Cu or Zn levels; (2) Se levels seemed to vary with age, but there was no relationship between Se level and disease stage; (3) the measurement of Cu/Zn was useful for assessing both prognosis and extent of the disease in NSCLC patients, similar to the measurement of serum tumor markers such as CEA; and (4) the measurement of the Cu/Zn had prognostic significance, but was inferior to disease stage in predicting outcome. Cu and Zn in serum are storable and the determination of Cu/Zn level is so simple and inexpensive that it can be helpful in determining clinical stages and predicting the prognoses of NSCLC patients.