Prognostic value of tumor-infiltrating T-lymphocytes density in the therapeutic response to initial platinum-based chemotherapy in patients with non-small cell lung cancer

Background/Aim. The fact that lung carcinomas, like other solid tumours, can be immunogenic, may have a substantial prognostic value in non-small cell lung cancer. Specific cytotoxic T-lymphocytes can be demonstrated in most patients with primary tumours of different histological types. Two main groups of T-lymphocytes participate in the coupled recognition of tumour-specific antigens - cytotoxic T-lymphocytes (CD8+, cluster of differentiation 8) and helper T-lymphocytes (CD4+, cluster of differentiation 4). The main goal of this research was to assess the relationship between the tumour infiltration of T-lymphocytes and the therapeutic response to initial chemotherapy. Methods. Data were obtained from patients with non-small cell lung cancer whose therapeutic response after four cycles of initial platinum chemotherapy was observed in relation to the density of tumour-infiltrating T-lymphocytes (CD4+ and CD8+) in small tumour biopsy samples. The therapeutic response was assessed in line with RECIST 1.1. therapeutic response evaluation system. Based on the expected therapeutic response, the patients were divided into three following groups: favourable therapeutic response patients (complete and partial regression), stable disease patients and disease progression patients. To assess the density of CD4+ and CD8+ T-lymphocytes, the number of lymphocytes was determined at x200 (1.1mm2) magnification. Three visual fields with the most dense lymphocyte infiltrate were selected for counting, and the values of all individual fields were added up. Based on the mean value, the samples were classified into the following groups: score 0, 1, 2 and 3. During statistical processing of the data, low infiltration density combined score 0 and score 1 group, and high infiltration density combined score 2 and score 3 group. Based on the collected data, a database was created in SPSS 22.0 software and used for further statistical analysis. The statistical analysis of the data included the method of descriptive and analytical statistics. Results. The results did not show any difference in distribution of CD4+ T-lymphocytes in epithelial components between patients with a different therapeutical response (?2=2,977; p= 0.226). Also, there was not any significant difference in the distribution of CD8+ T-lymphocytes in epithelial component between patients with a different therapeutical response (?2=1,329; p=0.515). There was no significant influence of the infiltration density of CD4+ T-lymphocytes in the stromal component on the therapeutic response (?2=0,606; p=0.739) and also, there was no significant influence of the infiltration density of CD8+ T-lymphocytes in stromal component on the therapeutic response (?2=5,167; p=0.076). Conclusion. The research did not prove that patients with a high level of tumour-infiltrating CD4+ and CD8+ T-lymphocytes in the epithelial and stromal component of the tumour (non-small cell lung cancer) had a better therapeutic response to standard initial chemotherapy.