Analysis of Circulating miRNAs as Potential Biomarkers of Diagnosis and Prognosis in High Grade Serous Ovarian Cancer

High grade serous ovarian cancer represents the gynecological malignancy with the highest incidence of mortality. Decision-making tools are currently limited to the use of standard imaging modalities and analysis of serum biomarkers, such as CA 125, which often have low specificity and sensitivity. Recently, a growing research interest has been aimed at so-called circulating microRNAs (miRNAs). Indeed, it has been observed that miRNAs are abundantly present in all biological fluids and play the key role of messengers in intercellular communication. Cancer cells have a rapid turnover which results in a continuous release of nucleic acids and vesicles derived from the tumor itself, such as the tumor cells themselves that separate from the tumor mass to enter the bloodstream. Given their important role as modulators of gene expression, in order to preserve their integrity, miRNAs are encapsulated in specific vesicles, in order to prevent their degradation by the enzymes present in biological fluids. In this context, the chance of monitoring the expression levels of specific miRNAs represents a very interesting option both for an early diagnosis and for monitoring the clinical response to pharmacological treatment. Currently, there are no non-invasive approaches to monitor the clinical outcome in real time, while the identification of circulating biomarkers would allow prompt intervention, possibly modifying the pharmacological management in case of progression.