101. Programmed Death-1 Ligand-1 (PD-L1) Expression and Clinicopathologic Correlation in Salivary Gland Tumors.
- Author
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Özer, Tuğçe Pütürgeli, Saylam, Güleser, Han, Ünsal, Öcal, Bülent, Bayır, Ömer, and Korkmaz, Mehmet Hakan
- Subjects
PROGRAMMED death-ligand 1 ,SALIVARY gland cancer ,SALIVARY glands ,SECONDARY primary cancer ,TUMOR classification ,HODGKIN'S disease - Abstract
Objective: Studies on markers such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein-1 (PD-1) and programmed death ligand-1 (PD-L1) that transmit negative signals to cells have gained importance. Immunotherapies using checkpoint inhibitors like Anti-PD-1 and anti-PD-L1 (Programmed death-1 and ligand-1) have changed the management standards and prognoses of the diseases including malignant melanoma, lung cancer, renal cancer, Hodgkin's lymphoma. Accordingly, we planned a prospective study to investigate PD-L1 expression in patients who were operated on in our clinic for salivary gland tumors. Methods: Records of patients who were aged over 18 years and operated on and followed-up for a major or minor primary salivary gland tumor in our Ear Nose and Throat (ENT) and Head and Neck Surgery Clinic of the tertiary healthcare institution in the years from 2008 through 2018 were reviewed. Patients who had a second primary tumor, previously received chemotherapy or radiotherapy for another condition, were receiving immunosuppressive therapy or taking immunomodulatory medication were excluded. In total 80 patients, 70 with malignant pathology and 10 with benign pathology, were included in the study. The cases were grouped by diagnoses. The groups were evaluated in terms of age, gender, smoking, tumor localization, locoregional and distant metastasis (TNM) stage, type of surgery, histopathologic diagnosis, tumor staging, perineural invasion, lymphovascular invasion, need for adjuvant treatment, recurrence or metastasis development. PD-L1 expression was explored in both tumor cells and tumor-infiltrating mononuclear cells placed in formalin-fixed paraffin blocks. Results: Of the 70 malignant primary salivary gland tumors included in our study, 17 (24.3%) stained positive for PD-L1. PD-L1 positivity was observed in 12 (85.7%) of the 14 high grade tumors, two (18.1%) of the 11 intermediate grade tumors, and three (10.7%) ofthe 28 low grade tumors (p=0.004). PD-L1 stained positive in 10 (76.9%) of the 13 patients with lymphovascular invasion (p=0.02). No significant relationship was identified between PD-L1 staining and gender, age, smoking, tumor size, histopathologic diagnosis, perineural invasion of tumor, nodal metastasis, distant metastasis, staging, recurrence and survival (p>0.05). Also, no significant relationship was identified between the PD-L1 expression in tumor-infiltrating mononuclear cells and gender, age, smoking, tumor size, histopathologic diagnosis, perineural or lymphovascular invasion (LVI) of tumor, nodal metastasis, distant metastasis, staging and recurrence (p>0.05). PD-L1 expression in tumor-infiltrating mononuclear cells was observed to be increased as PD-L1 expression increased in tumor cells (p=0.000). Conclusion: In malignant salivary gland tumors, PD-L1 expression is associated with the staging of the tumor and the presence of LVI. Tumor-infiltrating mononuclear cell count was seen to be increased as PD-L1 expression increased. These results suggest that immunomodulation (PD-1/PD-L1 pathway inhibition) may be a treatment option for predicting the prognosis, reducing recurrence risk and increasing survival in selected patients with salivary gland cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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