CD8+ T Cell Infiltration Predicts Chemoradiosensitivity in Nasopharyngeal or Oropharyngeal Cancer
Toshihiko Kawaguchi1, Takeharu Ono1, Fumihiko Sato1
1Department of Otolaryngology-Head and Neck Surgery, Kurume University School of Medicine, Kurume, Fukuoka, Japan.
Objectives:
Limited information exists regarding the associations between pre-existing immune parameters in the tumor immune microenvironment (TIM) and either chemoradiosensitivity or prognosis for patients with squamous cell carcinoma of the nasopharynx or oropharynx involving virus-related or nonvirus-related tumors.
Study Design:
Retrospective cohort study.
Methods:
We retrospectively reviewed 141 patients with EBV+, p16+, or EBV- and p16- statuses who are receiving chemoradiotherapy. We performed immunohistochemistry using pretreatment biopsy specimens to analyze the programed death ligand 1 (PD-L1) levels in tumor and immune cells and CD8+ tumor-infiltrating lymphocyte (TIL) density. We evaluated chemoradiosensitivity and prognosis with respect to these immune-related parameters.
Results:
Virus-related tumors showed associations with both PD-L1 expression and high CD8+ TIL density. Patients with higher CD8+ TIL density or greater numbers of PD-L1+ tumor and immune cells showed significant rates of favorable local recurrence-free survival (LRFS), progression-free survival (PFS), and overall survival (OS). Multivariate analyses demonstrated that higher CD8+ TIL density is an independent, significant, and favorable predictive factor for LRFS (P = .005) and OS (P = .003), although it is not a significant predictor of PFS (P = .077).
Conclusions:
Higher CD8+ TIL density represents a useful and favorable biomarker of chemoradiosensitivity in patients receiving chemoradiotherapy for nasopharyngeal or oropharyngeal cancer.
Level Of Evidence:
3 Laryngoscope, 131:E1179-E1189, 2021.
