Abstract
Renal cell carcinoma (RCC) is an immunogenic tumor and pathological specimen generally contain large quantities of tumor-infiltrating lymphocytes (TILs). Numerous cell types and cytokines could affect the immune escape mechanism of tumor cells. The aim of the present study was to investigate the prognostic impact of TILs and the associated circulating cytokines on localized clear cell RCC following radical nephrectomy. A total of 87 patients who had undergone radical nephrectomy and were pathologically diagnosed with localized clear cell RCC were included. The present study evaluated the profile of TILs with immunohistochemical analysis of tumor specimens using a panel of antibodies [cluster of differentiation (CD)-4, CD8, CD80, CD86, CD276, and Forkhead box p3 (Foxp3)]. Counts of each TIL were compared with clinicopathological variables. Based on the results of immunohistochemical analyses, putative cytokines, including interleukin (IL)-6, IL-10, IL-17, interferon-γ, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β, were selected, and their levels in preoperative serum were measured by ELISA. The levels were compared with TIL counts in tumor specimens. High counts of the CD276+ and Foxp3+ TILs were identified as independent factors for poor prognosis for metastasis and local recurrence following radical nephrectomy (P=0.033 and 0.006, respectively). A high CD276+ TIL count was associated with preoperative serum levels of TNF-α and IFN-γ (P=0.027 and P=0.035, respectively), whereas a high count of Foxp3+ TILs was associated with preoperative serum levels of TGF-β (P=0.021). High levels of TNF-α and TGF-β were associated with recurrence-free survival (P=0.035 and P=0.031, respectively). Topical intra-tumoral immunoreaction and systemic immune status may be associated with patients with localized RCC. The topical induction of the CD276+ and Foxp3+ TILs was suggested to be associated with high levels of serum TNF-α and IFN-γ. Preoperative serum levels of TNF-α and TGF-β could be simple and non-invasive biomarkers for risk stratification before radical surgery.