Role of IL-17A and IL-17RA in Prostate Cancer with Lymph Nodes Metastasis: Expression Patterns and Clinical Significance

SIMPLE SUMMARY: Prostate cancer (PCa) is the second most common type of cancer among men. The expression of IL-17A cytokine and its receptor IL-17RA may be used to predict the risk of aggressive prostate cancer. We examined the clinical data of 77 patients with PCa and lymph node metastasis (LN+) and then evaluated the levels of IL-17A and IL-17RA expression in the prostate and LN+. We found significant correlations between the investigated markers’ expression levels in examined tissues and clinical data, such as body mass index (BMI), the percentage of involved lymph nodes, or the European Association of Urology (EAU) risk group. The findings of this study suggest that IL-17A and IL-17RA may be useful in predicting the risk of aggressive prostate cancer; however, further studies are needed to determine their roles and potential clinical applications. ABSTRACT: Prostate cancer (PCa) is the second most frequently diagnosed cancer among men. The use of IL-17A and its receptor IL-17RA as prognostic markers for PCa has shown promising results. We analyzed the clinical data of 77 patients with PCa after radical prostatectomy with lymphadenectomy and lymph node metastasis (LN+). We assessed the expression levels of IL-17A and IL-17RA in cancer cells in prostate and, for the first time, also in LN+. Prostate IL-17A expression positively correlated with BMI (p = 0.028). In LN+, the expression of IL-17A was positively correlated with the percentage of affected lymph nodes (p = 0.006) and EAU risk groups (p = 0.001). Additionally, in the group with high IL-17A expression in LN+, the extracapsular extension (ECE) of the prostate was significantly more frequent (p = 0.033). Also, significant correlations with the level of IL-17RA expression was found—expression was higher in prostate than in LN+ (p = 0.009); in LN+, expression positively correlated with the EAU risk group (p = 0.045), and in the group of high expression in LN+ ECE of lymph nodes was detected significantly more often (p = 0.009). Our findings support the potential role of IL-17A and IL-17RA as PCa markers; however, further studies are needed to determine their roles and potential clinical applications.