Concordance between serum and cytosolic levels of CEA, CA125 and SCC antigens in patients with non-small cell lung cancer.

The relationship between serum and cytosolic levels of carcinoembryonic (CEA), squamous-cell carcinoma (SCC) and CA125 antigens was determined in 122 patients with non-small cell lung cancer. A pronounced serum-cytosol gradient and a high degree of dispersion in the distribution of serum and cytosol marker concentrations was detected. In addition, the degree of concordance between TM levels in the two compartments, determined by the intraclass correlation coefficient (ICC) index, was low (ICC = 0.42 for CEA; 0.35 for CA 125; and 0.27 for SCC). Tumour stage and histological type both played a limited role in the serum-cytosol relationship. As tumour stage advanced, the concordance between serum and cytosolic TM level became more pronounced. In addition, each histological type showed a distinctive pattern of expression of serum and cytosolic tumour markers, and a specific degree of concordance between levels in serum and cytosol. However, the ICC indices were always under 0.51, indicating that the importance of these factors is minor. The data obtained indicate that the relationship between serum and cytosolic concentration is moderate. The differences found according to stage grouping and histological subtype are so small that no clear-cut message for clinical practice can be drawn.