Prostate cancer (PCa) is the most commonly diagnosed cancer in men. The diagnosis is currently based on PSA levels, which are associated with overdiagnosis and overtreatment. Moreover, most PCas are localized tumours; hence, many patients with low-/very low-risk PCa could benefit from active surveillance (AS) programs instead of more aggressive, active treatments. Heterogeneity within inclusion criteria and follow-up strategies are the main controversial issues that AS presently faces. Many biomarkers are currently under investigation in this setting; however, none has yet demonstrated enough diagnostic ability as an independent predictor of pathological or clinical progression. This work aims to review the currently available literature on tissue, blood and urine biomarkers validated in clinical practice for the management of AS patients.

The purpose of this study is to clinically validate a series of circulating miRNAs that distinguish between the 4 most prevalent tumor types (lung cancer (LC); breast cancer (BC); colorectal cancer (CRC); and prostate cancer (PCa)) and healthy donors (HDs). A total of 18 miRNAs and 3 housekeeping miRNA genes were evaluated by qRT-PCR on RNA extracted from serum of cancer patients, 44 LC, 45 BC, 27 CRC, and 40 PCa, and on 45 HDs. The cancer detection performance of the miRNA expression levels was evaluated by studying the area under the curve (AUC) of receiver operating characteristic (ROC) curves at univariate and multivariate levels. miR-21 was significantly overexpressed in all cancer types compared with HDs, with accuracy of 67.5% (p = 0.001) for all 4 tumor types and of 80.8% (p < 0.0001) when PCa cases were removed from the analysis. For each tumor type, a panel of miRNAs was defined that provided cancer-detection accuracies of 91%, 94%, 89%, and 77%, respectively. In conclusion, we have described a series of circulating miRNAs that define different tumor types with a very high diagnostic performance. These panels of miRNAs would constitute the basis of different approaches of cancer-detection systems for which clinical utility should be validated in prospective cohorts.

Background: In recent years, liquid biopsy has emerged as a promising tool for the diagnosis and prognosis of numerous diseases, including cancer. Among the biomolecules analyzed in liquid biopsies are plasma circulating microRNAs (miRNAs), small non-coding RNAs that have proven to be crucial in the regulation of gene expression and the pathobiology of different health conditions, making them useful as biomarkers. However, variations in preanalytical conditions during biospecimen collection and processing can affect the analytical results. Objectives: Herein, we determined how the type of collection tube, the number of centrifugations, and the degree of hemolysis can affect plasma circulating miRNA levels. Methods: A cohort of 11 healthy donors was included. Whole blood was collected and handled in three different conditions, and miRNAs levels were analyzed using quantitative RT-PCR. Results: Our results show that the differences in the type of preservative tubes influence hemolysis, measured as OD at 414 nm. Moreover, the number of centrifugations performed also altered miRNAs levels, increasing or decreasing them depending on the miRNA analyzed. Hence, our study shows that alterations in preanalytical conditions affect miRNAs levels, particularly the number of centrifugations and the type of collection tubes. Conclusions: In our work, we highlight the importance of registering the preanalytical conditions in a standardized way that might be considered when analytical results are obtained.