Endothelin-1 levels in lung tissue of patients with non–small cell lung cancer with previous COVID-19 of varying severity.

e20045 Background: COVID-19 is a multisystem disease, largely due to vascular endothelial damage, and poses a risk to patients with non-small cell lung cancer (NSCLC), in whom the infection is more likely to progress to life-threatening conditions. Endothelin-1 (ET-1) is a potent vasoconstrictor, whose synthesis is induced by pulmonary infection and hypoxia. It has been shown that ET-1 is involved in the progression of the tumor process, but its role in patients with NSCLC who have recovered from COVID-19 remains unknown. The aim of research was to investigate the levels of endothelin-1 and its precursor in tissue of the tumor, perifocal zone and the resection line in patients with NSCLC who had previously suffered from COVID-19 of varying severity. Methods: The research included 80 patients of both sexes with verified NMSC of I-IIIA stages who had previously been infected with SARS-CoV-2. The main group consisted of 40 patients with severe/moderate severity COVID-19, while the control group included 40 patients with asymptomatic or mild cases. The content of ET 1-21 (active form) and ET 1-38 (precursor, non-active form) was determined using the ELISA method in tissue of the tumor, perifocal zone and the resection line. The Student's t-test as well as the Mann-Whitney test were used for statistical analysis. Results: The ratios of indicators in different zones of the lung tissue had sex differences. In men of the main group, the content of ET 1-21 was increased only in the perifocal zone of the tumor, by 1.9 times (p <0.05), and the level of ET 1-38 was increased in all studied zones by 1.5-2.6 times compared to the indicators in the control group. In the main group of women, the level of ET 1-21 was reduced by 2-2.7 times in the tumor and resection line tissue, while it did not differ from the control group in the perifocal zone, and the concentration of ET 1-38 was reduced by 4.9 times relative to this indicator in the control group only in the resection line tissue. Conclusions: Severe/moderate severity COVID-19 is associated with persistent changes in the ET-1 system in patients with NSCLC. Significant sex differences in the distribution of both forms of ET-1 in the lung tissue were found, which may reflect different mechanisms of the influence of SARS-CoV-2 on the tumor process in men and women. Particular attention should be paid to the pronounced accumulation of ET-1 in the perifocal zone of the tumor. It may contribute to the activation of angiogenesis and the progression of the disease.