OX40 and OX40L protein expression of tumor infiltrating lymphocytes in non-small cell lung cancer and its role in clinical outcome and relationships with other immune biomarkers

Lung cancer was one of the major fatal cancer types, which lead to 835,550 deaths in The United States in 2018 (1). With highly malignancy and limited early detection methods, patients usually had poor prognosis and limited survival. The early detection of pathological and molecular features of lung cancer could be beneficial to subsequent treatments and patients’ prognosis. Non-small cell lung cancer (NSCLC) is the major pathology type in lung cancer, which take up to nearly 80% of total incidence. Driving mutations mainly take place in adenocarcinoma, such as KRAS, EGFR, BRAF, NF1 and ALK fusion, even with one fourth of none mutation detected (2). Combing with first-line chemotherapy and anti-vascular therapy, recent clinical trials had already demonstrated the efficacy of target therapy in prolonging the survival and effectuate better disease management than ever before (3-7). Although target therapy and (or) anti-vascular therapy showed promising results in overall survival (OS) and progression-free survival (PFS), the beneficiary was limited, due to the fact that relatively small amounts of patients harbor the driving mutation (8). Also, acquired drug resistance and second mutations also rendered existing target medication ineffective, posing a new challenge for updating neo-generation target medication against mutations (9-11)