In patients with untreated tumors (lung cancer, head and neck tumors, stomach and colon cancer), erythrocyte membranes are characterized by a decreased content of total lipids together with increased percentage of cholesterol and lysophosphatidylcholine in comparison with healthy individuals. The observed shifts depend on tumor location.

Cytophotometric (sulfhydryl groups and lipoproteins) and interferometric (dry mass) studies of the peripheral blood erythrocytes were carried out in 94 untreated patients with tumors of different localization (lung cancer, tumors of the head and neck, gastric cancer, and cancer of the large intestine). Control group consisted of healthy volunteers. The concentrations of sulfhydryl groups, lipoproteins, and mean values of dry mass of red cells of the patients with tumors were reliably lower than those in healthy controls. The degree of changes in the studied parameters depended on the tumor localization.