title: Prognostic Value of Tumor-Infiltrating Lymphocytes for Patients With Head and Neck Squamous Cell Carcinoma.
abstract: BACKGROUND
  The prognostic value of tumor-infiltrating lymphocytes (TILs) in head and neck squamous cell carcinoma (HNSCC) remains controversial. Additionally, there is no standardized approach or cutoff value for evaluating TIL levels. The aim of this study was to establish a feasible method and criterion to assess TIL levels for future clinical practice and research use and to explore the relationship between TIL levels and prognosis.
  
  
  METHODS
  This retrospective cohort study reviewed the records and pathological sections of 202 patients with HNSCC who were surgically treated at Beijing Stomatological Hospital, Capital Medical University, from January 1998 to January 2011. The predictor variable was the TIL level. The main outcome assessment parameters were disease-free survival (DFS) and disease-specific survival (DSS).
  
  
  RESULTS
  The T stage (P = .008), smoking history (P = .042), alcohol history (P = .048), need for radiotherapy (P = .012) and microscopic extracapsular spread (ECS) (P = .012) were associated with the TIL level. A cutoff value equal to 70% could be taken as a threshold for TIL assessment, with a TIL level higher than 70% associated with a better prognosis (DFS rate: 51.9%, P = .018; DSS rate: 59.3%, P = .049). The Cox regression model showed that the TIL level was an independent prognostic factor for DFS (hazard ratio (HR): 0.786, 95% CI: 0.618-0.999, P = .049).
  
  
  CONCLUSIONS
  The TIL level is closely related to the prognosis of patients with HNSCC. A threshold value of 70% is appropriate for TIL assessment, as patients with a TIL level higher than 70% show a better prognosis. Thus, the TIL level might serve as an independent predictor for HNSCC recurrence.
authors.affiliation: Department of Oral and Maxillofacial-Head and Neck Oncology, Beijing Stomatological Hospital, Capital Medical University, Beijing, 100050, China.
authors.forename: Qiaoshi
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Department of Oral and Maxillofacial-Head and Neck Oncology, Beijing Stomatological Hospital, Capital Medical University, Beijing, 100050, China.
authors.forename: Chong
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Oral Pathology, Beijing Stomatological Hospital, Capital Medical University, Beijing, 100050, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Yuan
authors.affiliation: Department of Oral and Maxillofacial-Head and Neck Oncology, Beijing Stomatological Hospital, Capital Medical University, Beijing, 100050, China. Electronic address: jyfzhen@126.com.
authors.forename: Zhien
authors.initials: Z
authors.lastname: Feng
authors.affiliation: Department of Oral and Maxillofacial-Head and Neck Oncology, Beijing Stomatological Hospital, Capital Medical University, Beijing, 100050, China. Electronic address: hanf1989@hotmail.com.
authors.forename: Zhengxue
authors.initials: Z
authors.lastname: Han