Abstract
Background: The complex metabolic disorders and non-specific clinical manifestations that accompany the development of malignant neoplasm are characterized as a syndrome of endogenous intoxication.

Aims and Objectives: The aim of this study is to establish the patterns of changes in the parameters of endogenous intoxication and lipid peroxidation processes in the saliva of patients with non-small-cell lung cancer (NSCLC) depending on the presence/absence and extent of prevalence of distant and regional metastasis.

Materials and Methods: A total of 505 people took part in the case-control study: The main group (NSCLC, n = 290) and the control one (healthy, n = 215). All participants were questioned and underwent the biochemical examination of saliva and histological verification of the diagnosis. The parameters of endogenous intoxication and lipid peroxidation were determined spectrophotometrically.

Results: Dynamic regularities of lipid peroxidation indicators are highly pronounced with metastasis in lymph nodes regardless of histological type of the lung cancer. Hence, alongside regional metastasis, the level of diene conjugates decreases, whereas the level of triene conjugates and Schiff bases increases. Dynamics of albumin concentration is mainly due to regional metastasis, but the presence of distant metastases in the lungs drops albumin concentration greatly. The nature of changes in the malondialdehyde concentration is generally similar with the presence/absence of distant metastases, the maximum accumulation of lipid peroxidation products is observed for stages N3M0 and N3M1. Distribution coefficient МСМ 280/254 nm varies differently: It grows only in case of regional metastasis and reduced in case of distant metastasis for both histological types of the NSCLC.

Conclusion: The results of the study support the hypothesis of association of endogenous intoxication and lipid peroxidation processes with the development of NSCLC.

Key words: Saliva; Medium Molecular Weight Toxins; Lipid Peroxidation; Lung Cancer; Oncology