RESUMO
The purpose of the study was to investigate significance of the tumor marker pyruvate kinase Tumor M2 (Tu M2-PK), in diagnostics, monitoring of treatment, and evaluation of its effectiveness in patients with lung cancer (LC). This is an isoform of the glycosile enzyme pyruvate kinase, existing as an active dimer and less active tetramer. The expression of the less active form is typical of tumor cells; its blood level can be measured. The subjects of the study were 140 patients with LC of various histologic types. Serum levels of certain tumor markers (Cyfra 21-1, NSE, SCC, and Tu M2-PK) were measured; Tu M2-PK level was determined by ELISA test from ScheBoTech, a two-stage sandwich immunoassay using one type of antibodies. The marker concentration was also determined in 195 healthy volunteers (control group.) The maximum concentration of Tu M2-PK was 12.9 U/ml, determined with 95% specificity. 78% of the patients with small-cell carcinoma, 73% of patients with adenocarcinoma, and 81% of patients with non-small cell lung carcinoma displayed increase of Tu M2-PK serum concentration; this concentration was within normal limits in patients with nonmalignant diseases (e.g. bronchitis or tuberculosis). Thus, patients with lung carcinoma display a pathologic increase of Tu M2-P level. Measurement of Tu M2-P may be useful in patients with suspected LC; this marker may be of greater diagnostic significance than SCC or NSE.
