Clinicodiagnostic significance of the tests of structural and functional properties of serum albumin in small-cell lung cancer patients

The results of a comprehensive study of physicochemical properties of the conformational state of serum albumin by means of electron paramagnetic resonance (EPR) were analysed in small-cell cancer patients (n=25), non-small-cell cancer patients (n=30) and patients with chronic nonmalignant lung diseases (n=25) before special treatment. Lung cancer was established to cause marked disorders in physicochemical properties of serum albumin. Local changes in the conformational state of the protein biopolymer are expressed most of all in small-cell lung cancer patients and are manifested by nonspecific increase in specific capacity in the first binding centre with concurrent reduction of it in the 2nd centre, by decrease in intramolecular volumes of the centres, lowering conformational mobility and lability of serum albumin binding centres. The evaluation of albumin physicochemical properties is informative for differential diagnosis of small-cell lung cancer. The extent of structural and functional changes in lung cancer patients correlates with the morphological type of the tumor.