Tsung-Wei Chen1,2, Kevin Chih-Yang Huang3,4, Shu-Fen Chiang5, William Tzu-Liang Chen6, Tao-Wei Ke6, K S Clifford Chao7. 1. Graduate Institute of Biomedical Science, China Medical University, Taichung, 40402, Taiwan. 2. Department of Pathology, China Medical University Hospital, China Medical University, Taichung, 40402, Taiwan. 3. Translation Research Core, China Medical University Hospital, China Medical University, Taichung, 40402, Taiwan. 4. Department of Nutrition, HungKuang University, Taichung, 43302, Taiwan. 5. Cancer Center, China Medical University Hospital, China Medical University, 9F, Rehab Building, No.2 Rude Rd., Taichung, 40402, Taiwan. 6. Department of Colorectal Surgery, China Medical University Hospital, China Medical University, 7F First Medical Building, No.2 Rude Rd., Taichung, 40402, Taiwan. 7. Cancer Center, China Medical University Hospital, China Medical University, 9F, Rehab Building, No.2 Rude Rd., Taichung, 40402, Taiwan. chao_ks@yahoo.com.
Abstract
PURPOSE/ BACKGROUND: Radiotherapy has been recently reported to boost the therapeutic response of immune checkpoint blockade (ICB); however, few studies have focused on programmed cell death-ligand 1 (PD-L1) expression in locally advanced rectal cancer (LARC) patients who receive preoperative neoadjuvant chemoradiotherapy (neoCRT). The aim of the present study was to investigate the PD-L1 expression status and CD8+ intra-tumoral infiltrating lymphocytes (TILs) before and after neoCRT and its association with clinicopathological characteristics in rectal cancer. MATERIALS AND METHODS: Immunostainings of PD-L1 and CD8+ TILs were performed in 112 pair-matched LARC patients treated by neoCRT. Tumor PD-L1 expression and CD8+ TILs within the tumor microenvironment before and after neoCRT were evaluated via immunohistochemistry. RESULTS: High tumor PD-L1 expression was significantly increased from 50 to 63%, and high CD8+ TILs counts were also slightly increased from 32 to 35% after neoCRT treatment. High tumor PD-L1 before and after neoCRT was associated with improved disease-free survival (DFS, pre-neoCRT: p = 0.003 and post-neoCRT: p = 0.003) and overall survival (OS, pre-neoCRT: p = 0.045 and post-neoCRT: p = 0.0001). High CD8+ TILs before neoCRT was associated with improved DFS (p = 0.057), and it was significantly associated with improved DFS after neoCRT (p = 0.039). Patients with high tumor PD-L1 and CD8+ TILs before and after neoCRT were significantly associated with improved DFS (pre-neoCRT: p = 0.004 and post-neoCRT: p = 0.006). CONCLUSION: The present results provide evidence that tumor PD-L1 expression and recruitment of CD8+ TILs within the tumor microenvironment were increased by neoCRT treatment. Tumor PD-L1 and CD8+ TILs are prognostic biomarkers for the survival of LARC patients treated with neoCRT.
PURPOSE/ BACKGROUND: Radiotherapy has been recently reported to boost the therapeutic response of immune checkpoint blockade (ICB); however, few studies have focused on programmed cell death-ligand 1 (PD-L1) expression in locally advanced rectal cancer (LARC) patients who receive preoperative neoadjuvant chemoradiotherapy (neoCRT). The aim of the present study was to investigate the PD-L1 expression status and CD8+ intra-tumoral infiltrating lymphocytes (TILs) before and after neoCRT and its association with clinicopathological characteristics in rectal cancer. MATERIALS AND METHODS: Immunostainings of PD-L1 and CD8+ TILs were performed in 112 pair-matched LARC patients treated by neoCRT. TumorPD-L1 expression and CD8+ TILs within the tumor microenvironment before and after neoCRT were evaluated via immunohistochemistry. RESULTS:High tumor PD-L1 expression was significantly increased from 50 to 63%, and high CD8+ TILs counts were also slightly increased from 32 to 35% after neoCRT treatment. High tumor PD-L1 before and after neoCRT was associated with improved disease-free survival (DFS, pre-neoCRT: p = 0.003 and post-neoCRT: p = 0.003) and overall survival (OS, pre-neoCRT: p = 0.045 and post-neoCRT: p = 0.0001). High CD8+ TILs before neoCRT was associated with improved DFS (p = 0.057), and it was significantly associated with improved DFS after neoCRT (p = 0.039). Patients with high tumor PD-L1 and CD8+ TILs before and after neoCRT were significantly associated with improved DFS (pre-neoCRT: p = 0.004 and post-neoCRT: p = 0.006). CONCLUSION: The present results provide evidence that tumorPD-L1 expression and recruitment of CD8+ TILs within the tumor microenvironment were increased by neoCRT treatment. TumorPD-L1 and CD8+ TILs are prognostic biomarkers for the survival of LARC patients treated with neoCRT.
Authors: Ai Huang; Yong Xiao; Chunfen Peng; Tao Liu; Zhenyu Lin; Qin Yang; Tao Zhang; Jun Liu; Hong Ma Journal: Strahlenther Onkol Date: 2019-12-11 Impact factor: 3.621