Comparison of Tumor Infiltrating Lymphocyte Density with Histopathological Parameters and Effect on Prognosis in Head and Neck Squamous Cell Cancers

The study aims to determine the ratio of the tumor-infiltrating lymphocytes (TIL) in the tumor microenvironment in squamous cell carcinoma of head and neck and its effect on prognosis using histopathological parameters. The patients who underwent head and neck surgery with the diagnosis of squamous cell carcinoma of head and neck at Cerrahpaşa medical faculty ENT Clinic between January 2010 and November 2013 were included in this study. The age, gender, smoking status, alcohol use, radiologic images, and operation technique were analyzed for all patients. TNM pathologic staging, histologic differentiation grade, desmoplastic stromal reaction, vascular and perineural invasion, and lymph node metastasis were also evaluated. Representative hematoxylin-eosin stained slides from each block were cut and the ratio of tumor-infiltrating lymphocytes in tumor tissue was examined by an expert to confirm histology. In this study, 114 patients (105 males and 9 females) met inclusion criteria and were included. The mean age was 60.3±9.7 (ranging from 27 to 85 years). TIL and desmoplastic stromal reaction were compared statistically to the extent of primary tumor, vascular and perineural invasion, lymph node metastasis and histological grade of the tumor. While there was no statistically significant difference between TIL and these parameters, there was a statistically significant correlation between desmoplastic stromal reaction and these parameters. Considering five years of patient survival, although TIL had a positive impact on the prognosis of the tumor, there was no statistically significant difference. We suggest that besides TNM pathologic staging and histologic parameters, immune cells reacting to the tumor will be a distinctive factor in determining the prognosis and new treatment methods. We believe that TIL will affect the current cancer treatments by increasing its anti-tumor effects and will give promising results in cancer immunotherapy.