The effect of neoadjuvant chemotherapy / chemoradiotherapy on tumor tissue pd-l1 and VISTA expression level in stage 3 non-small cell lung cancers

Lung cancer is the most common cancer in men and the second most common cancer in women worldwide. Non-Small Cell Lung Cancer (NSCLC) constitutes approximately 80% of lung cancer. The development of immune checkpoint inhibitors (ICIs) targeting programmed cell death 1 (PD - 1) or its ligand (PD - L1) has significantly changed the treatment of local advanced and advanced NSCLC. Radiation has been shown to induce tumor antigen release and increase PD-L1 expression. This effect has made the combined use of radiotherapy and checkpoint inhibitors the main focus of many studies. It has been shown that VISTA (V-domain Ig Suppressor of T Cell Activation), another checkpoint receptor, also plays an immunomodulatory role in NSCLC and can be therapeutic target. Therefore, in this study, we aimed to evaluate the expression level of PD-L1 and VISTA after neoadjuvant chemotehrapy or chemoradiotherapy in Stage 3 Non-Small Cell Lung Cancer patients. Patients with pathological diagnosis of Non-Small Cell Lung cancer, tumor stages 3a, 3b and 3c were operated after neoadjuvant chemotherapy or chemoradiotherapy and followed in Gazi University Medical Faculty Oncology Department were included in study. The expression levels of PD-L1 and VISTA between pre-and post- treatment tissue biopsies of these patients were evaluated. Thirty four patients meeting the appropriate criteria were included in the study. When we look at the results of our study, it has been shown that PD-L1 and Vista levels increase in tumor tissue after neoadjuvant chemotherapy or chemoradiotherapy (p value for PD-L1 0.004, p value 0.025 for VISTA). While the PD-L1 level of 22 patients at the time of diagnosis was <1%, after treatment, the PD-L1 level of 11 patients was evaluated as <1%, and an increase in the PD-L1 level was found in 14 patients after treatment. While Vista level of 20 patients at the time of diagnosis was <1% ,it was found that the Vista level of 12 patients after treatment was <1% and 15 patients had an increase in Vista level after treatment.High PD-L1 level at the time of diagnosis was found to be associated with decreased survival. There was no relationship between Vista level and survival ( p value 0.534). Immunotherapy is a promising treatment modality in patients with NSCLC. Chemotherapy and radiotherapy can be used as immunizers to increase the effect of immunotherapy. There is a need for larger studies on this subject, broader analyzes with treatment subtypes and studies evaluating Vista as a treatment target.