Objective. To assess the possibility of using laboratory blood parameters of patients with stage III squamous cell lung cancer (SCLC) at the preoperative stage to determine the risk of tumor recurrence.

Materials and methods. The study of relapse-free survival and the formation of risk groups was carried out on the basis of the data of the Belarusian Cancer Registry for 416 patients with newly diagnosed stage III SCLC. In the blood of these patients the concentration of cells was determined, in the blood serum — the concentration of C-RP and albumin.
In 39 patients the concentration of antigens CYFRA 21-1 (cytokeratin-19 fragment), SCC (subfraction of the serine protease inhibitor TA-4), TPA (tissue polypeptide antigen), chemokines CXCL5, CXCL8, pyruvate kinase isoenzyme TuM2 PK and hyaluronic acid were determined in the blood serum ; the proportion of blood cells equipped with CXCR1, CXCR2, CD44v6 receptors and the localization density of these receptors on them were also measured.

Results. All examined patients were divided into groups of low (T1N2M0, T3N1M0, T2N2M0, T4N0M0, T3N2M0) and high (T4N1M0 and T4N2M0) risk of tumor recurrence based on the Kaplan Meier plots. In patients of these groups the relative number of lymphocytes with the CXCR1 receptor, the proportion of monocytes with the CXCR2 receptor in their total population, and the concentration of CYFRA21-1 differed significantly. The prognostic efficiency of the determination results varied from 71,8 to 76,9 %. A mathematical model was built, which included a combination of these indicators.
It made it possible to increase the forecast efficiency up to 87,2 %.

Conclusion. The risk of postoperative recurrence in patients with stage III SCLC can be predicted based on the results of determining in the blood complex of laboratory parameters, which includes the concentration of CYFRA21-1, the relative number of lymphocytes equipped with the CXCR1 receptor, and monocytes equipped with the CXCR2 receptor.