An Evaluation of Serum miRNA in Renal Cell Carcinoma: A Systematic Review

Background: In recent years, research has highlighted the importance of microRNAs (miRNAs) in the context of oncological diseases, including renal cell carcinoma (RCC). The aim of this systematic review of the literature was to analyze the main serum miRNAs involved in RCC and their potential diagnostic power. Methods: This systematic review was performed following the PROSPERO protocol CRD42024550709. Literature search strategies were developed composing strings with text words related to serum miRNA in RCC for PubMed, EMBASE and Clinicaltrial.gov. The studies enrolling adult populations with RCC and healthy controls measuring circulating miRNAs were included. Results: We found 500 records, and 26 papers were included after screening. Four studies found that miR-210, the most investigated miRNA, was overexpressed in RCC patients compared to controls, while one reported no statistical difference. The expression of some miRNAs was consistently lower in cases compared to healthy controls, such as miR-1-3p and miR-129-5p, while others (miR-221, miR-222, miR-224-5p and miR-1233) were consistently upregulated. Conclusions: Circulating miRNAs represent a promising avenue for the non-invasive diagnosis of RCC. Future research should focus on standardization, validation in larger cohorts and the development of multi-marker diagnostic panels to address these current limitations and pave the way for miRNA-based diagnostics in RCC.