Evaluation of Urinary miRNA in Renal Cell Carcinoma: A Systematic Review

Background and Objective. The significance of microRNAs (miRNAs) in relation to neoplastic diseases; such as renal carcinoma carcinoma (RCC); has been brought to light by recent studies. Analyzing the main urinary miRNAs implicated in RCC and their potential diagnostic use was the goal of this systematic review of the literature. Methods. This systematic review was performed following the PROSPERO protocol CRD42024550716. Our literature search strategies were deciding which database to include (Pubmed; EMBASE and Clinicaltrial.gov) and composing strings with words related to urinary miRNA in patients with RCC. Key findings and limitations. After screening; 10 papers were included from the 593 records that the systematic review found. No miRNA was investigated in more than one paper by different authors. The miR-210 and let-7 family were the most investigated and resulted upregulated in RCC cases compared to controls. Five papers reported different expression of miRNAs in urine samples before and after surgery: miR-15a; miR-34a-5p; miR-200a-3p; miR-205-5p; miR-210; miR-210-3p; miR-365a-3p and let-7d-5p levels decreased after nephrectomy. Meta-analysis was not performed since the included studies were heterogeneous; in terms of studied miRNA; of the normalizer used during stabilization phase; and histologic type of RCC (clear cell RCC; papillary RCC; unspecified RCC). Conclusions. Considering the variability and heterogeneity of the obtained results; as well as the vastness of the topic; expanding research in this field appears highly promising. To support further advancements; it would be useful to establish a database that consolidates international findings.