The relationship of TH17 with survival and recurrence in non-small cell lung cancer

Objective: The presence of IL-17-positive cells is observed in lung cancer as well as in various cancers. Although the role of TH17 cells in lung cancer is still not clear, it is generally associated with short survival and poor prognosis. This study aimed to determine the prognostic significance of IL-17 in NSCLC patients and to examine the relationship between IL-17 expression in NSCLC tissues and blood, and recurrence and survival. Methods: The expression of IL-17 was analyzed by immunohistochemistry in archived tumor and healthy tissue at -80°C' of 39 NSCLC patients and by ELISA in serum from archived peripheral blood samples of 41 NSCLC patients. The χ2 test was used to analyze the correlation between IL-17 expression and clinical parameters. The Kaplan-Meier method was used to analyze the correlation between IL-17 expression and overall survival and disease-free survival. Results: Higher levels of IL-17A were detected in tumor tissue compared to healthy tissue. High IL-17 expression was observed in 51.3% of 39 NSCLC patients in healthy and tumor tissue and 47.6% of 41 patients in serum. Of the patients, 38.4% were diagnosed with adenocarcinoma and 50.6% with squamous cell carcinoma. 23.1% of the patients that L-17A was analyzed in healthy and tumor tissues and 34.1% of the patients that IL-17A was analyzed in the serum were evaluated as an advanced stage. It was observed that IL-17A was expressed at significantly higher levels in squamous cell lung cancer than in adenocarcinoma. In tissue analyzes, low IL-17A levels in early-stage disease were associated with longer disease-free and overall survival times. In the advanced stage patient group, unlike adenocarcinoma, the patients with squamous cell lung cancer diagnosed with higher IL-17A levels had a longer disease-free survival time than those with low IL-17A levels, although it was not statistically significant. Conclusion: IL-17A is an immune system regulator that plays a role in disease-free survival and lung cancer metastasis according to histopathological diagnosis and TNM stage of lung cancer.