33PPrognostic value of CD8-positive tumor stroma-infiltrating lymphocytes and PD-L1 positive tumor cells at initial biopsy in patients with locally advanced NSCLC treated with chemoradiotherapy

Background: According to results of PACIFIC trial, immune checkpoint inhibitors (CPIs) are an integral part of the multimodal treatment approach for inoperable locally-advanced non-small cell lung cancer (LA-NSCLC). The purpose of this single-center study was to investigate a prognostic value of CD8-positive tumor stroma-infiltrating lymphocytes (TILs) and PD-L1 positive tumor cells at initial biopsy in patients treated with definitive chemoradiotherapy (CRT).Methods: We collected initial tumor tissue samples and reviewed the clinical characteristics of 36 LA-NSCLC patients treated at our center with definitive CRT between 2000 and 2004. The analyzed tumor tissue was taken before start of multimodal treatment. An experienced pathologist performed...