Correlation of Intra-tumoral and Peripheral PD-1/PD-L1 Immunity in Head and Neck Cancer.

BACKGROUND/AIM: Head and neck squamous cell carcinoma (HNSCC) represents a heterogeneous malignant disease of the oral cavity, pharynx, and larynx. HNSCC cells evade the host immune system through alterations in their immunogenicity, production of immunosuppressive mediators, and induction of immunomodulatory cell types. The immune status of solid HNSCC can be considered as hot, cold, or excluded for each patient individually, based on the distribution of tumor infiltrating immune cells. In this context immunotherapies based on the blockade of checkpoint molecules programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1) have significantly improved therapeutic outcomes in different cancer types. In HNSCC, intra-tumoral expression levels of PD-L1 are used for decision making in checkpoint inhibitor treatment. The significance of PD-L1 as a prognostic indicator is still controversial because both PD-1 and PD-L1 are also expressed in different types of circulating immune cells and the interaction of systemic and intra-tumoral cell-type-specific expression patterns of checkpoint molecules PD-1/PD-L1 has not yet been fully unveiled. MATERIALS AND METHODS: Using immunohistochemical (IHC) staining and flow cytometry, we correlated the expression patterns of the checkpoint molecules PD1/PD-L1 in peripheral blood CD14/CD16 monocytes and CD4/CD8 T cells with intra-tumoral conditions in patients with head and neck cancer. RESULTS/CONCLUSION: Our data demonstrate significant connections between systemic and intra-tumoral PD-1/PD-L1 immune patterns, both of which may serve as promising combined biomarkers for treatment decisions in patients with head and neck cancer.

TRIM21 Expression as a Prognostic Biomarker for Progression-Free Survival in HNSCC.

Patients with head and neck squamous cell carcinoma (HNSCC) continue to have a rather poor prognosis. Treatment-related comorbidities have negative impacts on their quality of life. TRIM21 is a cytosolic E3 ubiquitin ligase that was initially described as an autoantigen in autoimmune diseases and later associated with the intracellular antiviral response. Here, we investigated the role of TRIM21 as a biomarker candidate for HNSCC in predicting tumor progression and patient survival. We analyzed TRIM21 expression and its association with clinical-pathological parameters in our HNSCC cohort using immunohistochemistry. Our HNSCC cohort included samples from 419 patients consisting of primary tumors (n = 337), lymph node metastases (n = 156), recurrent tumors (n = 54) and distant metastases (n = 16). We found that cytoplasmic TRIM21 expression was associated with the infiltration of immune cells into primary tumors. In addition, TRIM21 expression was significantly higher in primary tumors than in lymph node metastases, and increased TRIM21 expression was correlated with shorter progression-free survival in HNSCC patients. These results suggest that TRIM21 could be a new biomarker for progression-free survival.

TRIM24 Expression as an Independent Biomarker for Prognosis and Tumor Recurrence in HNSCC.

BACKGROUND: Head and neck squamous cell carcinomas (HNSCCs) are among the most common cancers in humans worldwide and have a rather poor prognosis. TRIM24 has various intracellular functions and was identified in other cancer entities as a poor prognostic factor for patients. METHODS: The expression of TRIM24 was evaluated by using immunohistochemistry. We used a large and representative cohort of 341 HNSCC patients. Data derived from immunohistochemistry evaluation was correlated with clinicopathological data from HNSCC patients. RESULTS: The TRIM24 expression in HNSCC primary tumors is negatively correlated with the p16 status of the tumor tissues. Primary tumors of patients who developed a local recurrence were significantly more often positive for TRIM24. Kaplan-Meier analyses and Cox regression showed that patients with TRIM24 expressing tumors have significantly worse overall survival and progression-free survival and that TRIM24 expression is independent of other established risk factors. CONCLUSIONS: TRIM24 might be a new prognostic biomarker for the survival prognosis and early detection of local recurrences in HNSCC patients. It could be used for risk stratification of HNSCC patients and to identify those patients who are more prone to develop a local recurrence and therefore could profit from more frequent follow-up examinations.