Liquid biopsies for liquid tumors: emerging potential of circulating free nucleic acid evaluation for the management of hematologic malignancies

Circulating free nucleic acids; cell free DNA and circulating micro-RNA, are found in the plasma of patients with hematologic and solid malignancies at levels higher than that of healthy individuals. In patients with hematologic malignancy cell free DNA reflects the underlying tumor mutational profile, whilst micro-RNAs reflect genetic interference mechanisms within a tumor and potentially the surrounding microenvironment and immune effector cells. These circulating nucleic acids offer a potentially simple, non-invasive, repeatable analysis that can aid in diagnosis, prognosis and therapeutic decisions in cancer treatment.

Novel approaches in search for biomarkers of cholangiocarcinoma

Cholangiocarcinoma(CCA)arises from the ductular epithelium of the biliary tree,either within the liver(intrahepatic CCA)or more commonly from the extrahepatic bile ducts(extrahepatic CCA).This disease has a poor prognosis and a growing worldwide prevalence.The poor outcomes of CCA are partially explained by the fact that a final diagnosis is challenging,especially the differential diagnosis between hepatocellular carcinoma and intrahepatic CCA,or distal CCA and pancreatic head adenocarcinoma.Most patients present with an advanced disease,unresectable disease,and there is a lack in non-surgical therapeutic modalities.Not least,there is an acute lack of prognostic biomarkers which further complicates disease management.Therefore,there is a dire need to find alternative diagnostic and follow-up pathways that can lead to an accurate result,either singlehandedly or combined with other methods.In the"-omics"era,this goal can be attained by various means,as it has been successfully demonstrated in other primary tumors.Numerous variants can reach a biomarker status ranging from circulating nucleic acids to proteins,metabolites,extracellular vesicles,and ultimately circulating tumor cells.However,given the relatively heterogeneous data,extracting clinical meaning from the inconsequential noise might become a tall task.The current review aims to navigate the nascent waters of the non-invasive approach to CCA and provide an evidence-based input to aid clinical decisions and provide grounds for future research.

Circulating microRNAs as a liquid biopsy: a next generation clinical biomarker for diagnosis of gastric cancer

Accumulating evidence has suggested the potential clinical utility of novel body fluid biomarkers,or“liquid biopsy”,using circulating tumor cells and cell-free nucleic acids from cancer patients.Noninvasive and reproducible,liquid biopsy could provide the basis for individualized therapeutic strategies by identifying genetic and epigenetic aberrations that are closely associated with cancer initiation and progression.MicroRNAs(miRNAs)are short noncoding RNAs that post-transcriptionally regulate gene expression.They also play important roles in various physiological and developmental processes as oncogenic or tumor-suppressive regulators.Specific miRNA expression signatures have been identified in a number of human cancers.Circulating miRNAs have been detected in plasma and serum,and this in blood has attracted the attention of researchers for their potential as noninvasive biomarkers.Circulating miRNAs have emerged as tumor-associated biomarkers that reflect not only the existence of cancer,but also the dynamics,malignant potential,and drug resistance of tumors.Herein,we review the recent biological and clinical research on the circulating miRNAs of gastric cancer and discuss future perspectives for their clinical applications as a liquid biopsy.