Characteristics of composition a lymphoid infiltrate in the tongue squamous cell carcinoma

Introduction. Squamous cell carcinoma of the tongue is the most common oral cancer. The tumor microenvironment has a significant impact on tumor progression; therefore, better understanding of its characteristics is crucial for the treatment strategy, since in some cases it modifies the tumor microenvironment resulting in tumor resistance to therapy.Study objective – to compare the number of CD8+Т-lymphocytes, CD57+NK-cells, and CD20+B-lymphocytes in the microenvironment of tongue squamous cell carcinoma in patients receiving and not receiving neoadjuvant chemoradiotherapy.Materials and methods. We performed immunohistochemical examination of specimens from 67 patients with tongue squamous cell carcinoma who did not receive neoadjuvant chemoradiotherapy. Eleven patients were diagnosed with well differentiated tumors (G1); 21 patients had moderately differentiated tumors (G2); and 35 patients had poorly differentiated tumors (G3). T1 tumors were observed in 11 individuals, T2 tumors – in 26 individuals, T3 tumors – in 26 individuals, and T4 tumors – in 4 individuals. We also examined 30 patients who had undergone neoadjuvant chemoradiotherapy, including external beam radiotherapy (total dose of 60 Gy) and a cycle of polychemotherapy (cisplatin and 5‑fluorouracil). Of them, 6 patients had T1 tumors, 17 patients – T2 tumors, 5 patients – T3 tumors, and 2 patients – T4 tumors. We measured the areas occupied by CD8+T-lymphocytes, CD20+B-lymphocytes, and CD57+NK-cells in the hot spots in the tumor microenvironment.Results. The number of CD8+T-lymphocytes in the tumor microenvironment was higher in patients after neoadjuvant chemoradiotherapy than in those who did not receive it (р = 0.000), whereas the number of CD20+B-lymphocytes was lower after neoadjuvant chemoradiotherapy. The area occupied by CD57+NK-cells in the hot spots of the tumor microenvironment did not differ significantly before and after therapy (p >0.05).Conclusion. Thus, neoadjuvant chemoradiotherapy in patients with tongue squamous cell carcinoma caused an increase in the number of CD8+T-lymphocytes, a decrease in the number of CD20+B-lymphocytes in the tumor microenvironment, and had no effect on the population of CD57+NK-cells.