Prognostic and predictive significance of GITR in metastatic renal cell carcinoma.

OBJECTIVE: Renal cell carcinoma (RCC) has gradually increased in recent years. There have been significant developments in metastatic RCC in recent years with the introduction of immune control point inhibitors. Glucocorticoid-induced tumor necrosis factor (TNF) receptor-related protein (GITR) is a co-stimulatory molecule and is seen in the highest amounts in activated CD4+ T lymphocytes and CD8+ T lymphocytes, forkhead box protein 3 (FOXP3) positive regulatory T cells (Treg). GITR leads to an increase in interleukin (IL)-2 and CD25 and Interferon Gamma. It shows an anti-tumoural effect by inhibiting the suppressive functions of FOXP3+ regulatory cells (Treg). Therefore, we aimed to evaluate the prognostic and predictive effect of GITR, tumor-infiltrating lymphocytes (CD4+CD8) (TIL), and FOXP3 in patients with metastatic RCC. PATIENTS AND METHODS: Patients diagnosed with pathologically confirmed metastatic renal cancer between 2016 and 2021 were included in our study. Clinicopathological features and some laboratory tests were recorded. GITR, CD4, CD8, and FOXP3 were evaluated by immunohistochemistry (IHC) from biopsies or nephrectomy material and recorded. RESULTS: The study included 41 patients. The median progression-free survival (PFS) was 10.5 months, and the median overall survival (OS) was 13.9 months. Median PFS was 7.9 months for the GITR-low group and 18.9 months for the GITR-high group. Median PFS was statistically significant and longer for the GITRhigh group than the GITR-low group (p=0.003). When patients who received nivolumab in the 2nd line were evaluated, median PFS was found to be 5.7 months in the GITR-low group and 15.7 months in the GITR-high group. Median PFS was statistically significantly higher in the GITR-high group than in the GITR-low group (p=0.026). CONCLUSIONS: In patients with metastatic RCC, higher GITR was associated with better PFS. At the same time, in patients using nivolumab, better PFS was seen in the GITR high group. If supported by prospective studies, GITR can be used as both a prognostic and predictive marker. [ABSTRACT FROM AUTHOR]