A nomogram based on circulating CD8+ T cell and platelet-to-lymphocyte ratio to predict overall survival of patients with locally advanced nasopharyngeal carcinoma oleh Chang Yan, Guohai Yang, Chaojun Zhang, KaiHua Chen, Yongchu Sun, Zhongguo Liang, Lin Lai, Ling Li, Song Qu, Xiao-Dong Zhu