Circulating microRNAs (miRNAs) in exosomes are emerging as clinically useful tools for cancer detection. However, little is known about their diagnostic impact in clear-cell renal cell carcinoma (ccRCC). To investigate whether miRNAs in serum exosomes can serve as biomarkers in ccRCC. Serum samples were obtained from 82 patients with ccRCC and 80 healthy volunteers. Exosomes were extracted and purified to selectively capture exosomes positive for tumor-associated epithelial cell adhesion molecule (EpCAM) via a magnetic bead technique. Total RNA was extracted and expression levels of miR-210, miR-1233, and miR-15a miRNAs were quantified and normalized to U6 levels. Expression levels were compared using a Mann-Whitney U-test, Friedman test, or Wilcoxon test. Receiver operating characteristic (ROC) curves were plotted to assess the diagnostic value of exosomal miRNAs for differentiation between ccRCC patients and controls. Expression levels of exosomal miR-210 and miR-1233 were significantly higher in ccRCC patients than in healthy individuals (both p<0.01). No significant difference was observed for exosomal miR-15a. Exosomal miR-210 and miR-1233 expression levels in different TNM stages were significantly higher than in the controls (all p<0.01). Exosomal miR-210 and miR-1233 expression levels were significantly lower in postoperative than in preoperative samples (both p<0.01). ROC analysis demonstrated that exosomal expression levels distinguished ccRCC patients from healthy individuals with 70% sensitivity and 62.2% specificity for miR-210, and 81% sensitivity and 76% specificity for miR-1233. The retrospective design and lack of other tumor subtypes are limitations of the study. Serum exosomal miRNAs might represent potential diagnostic biomarkers in ccRCC in the future. Circulating levels of exosomal microRNAs miR-210 and miR-1233 have potential as biomarkers for diagnostic and monitoring purposes in renal cancer in the future. These molecules can be measured in serum in so-called liquid biopsy.

Background:  Solid renal masses are found increasingly. Further analysis of the characteristics of solid renal masses is useful for optimal treatment.Methods:  A retrospective analysis of all solid renal masses was conducted from December 1998 to May 2003 at the Urology Department, Central University Hospital of Saint‐Etienne, France. A total of 162 solid renal masses were treated. The preoperative imaging diagnosis of ultrasound and computed tomography, and final pathological results were reviewed.Results:  One hundred and forty‐five tumors were pathologically confirmed to be renal cell carcinomas (RCC); 17 tumors (10.5%) were benign. There were eight renal oncocytomas, eight renal angiomyolipomas and one benign mixed epithelial/stroma tumor. Three oncocytomas and five angiomyolipomas were strongly suspected before surgery. The majority of the benign tumors were ≤4 cm. The percentage of small benign tumors (≤4 cm) was significantly higher than large benign tumors (>4 cm). Although it is possible to use imaging to detect some benign tumors, the majority of benign tumors cannot be diagnosed definitively by imaging before surgery.Conclusions:  Malignancy in solid renal masses is tumor‐size related. Benign solid renal tumors appear mainly as small‐sized tumors. The preoperative differentiation between an RCC and a benign tumor can be difficult. Our data suggest that a biopsy is necessary in selected patients to achieve the maximum accuracy in order to provide optimal treatment.

Objective: The objective of this study was to assess the possibility of using urinary exosomal CA9 mRNA as a novel liquid biopsy for the molecular diagnosis of bladder cancer. Patients and Methods: A total of 168 bladder cancer patients and 90 control subjects were included in the study. An isolation kit was used to isolate urinary exosomes. Transmission electron microscopy (TEM) was used to examine the presence of exosomes. Flow cytometry was used to examine the exosomal marker CD63. The expression level of exosomal CA9 mRNA was detected by RT-qPCR. The diagnostic performance of urinary urinary exosomal CA9 mRNA was evaluated. Results: TEM confirmed the enriched exosomes from urinary bladder patients. Flow cytometry indicated a strong positive expression of exosome marker CD63. Successful extraction of RNA was performed from exosome samples. The level of urinary exosomal CA9 mRNA was significantly higher in bladder cancer group than in control group (p< 0.001). The area under the ROC curve was 0.837 (95% CI: 0.743– 0.859) with a sensitivity of 85.18% and a specificity of 83.15% for the diagnosis of bladder cancer. Conclusion: We found that the urinary exosomes were abundant in the urine of bladder cancer patients. CA9 mRNA could be detectable in urinary exosomes. The urinary exosomal CA9 mRNA may present a new liquid biopsy for the diagnosis of bladder cancer.