Liquid biopsy

Efficient and non-invasive, liquid biopsy methods could greatly improve the molecular classification of gliomas. Here, the authors develop an RNA-based Droplet Digital PCR assay to detect the key IDH1.R132H mutation in plasma-derived extracellular vesicles from glioma patients with high sensitivity, allowing accurate diagnosis, prognostication and longitudinal monitoring.

Cell free DNA fragmentation is a promising biomarker for disease, but its epigenetic regulation is incompletely understood. Here, the authors investigated the effects of DNA methylation in the production of cfDNA fragmentation, and corelate these changes with gene expression in human cancer.

ctDNA is a known poor prognostic factor for multiple cancer types, but variant-specificity is unknown. Here, the authors show variant-specific association of ctKRAS levels with survival in previously untreated metastatic pancreatic ductal adenocarcinoma patients in multiple cohorts.

Ohannesian, Mallick et al. demonstrate label-free counting and detection of microRNA cargoes for single small extracellular vesicles (sEVs), revealing elevated sEV counts and distinct molecular contents in samples from patients with cancer. Using a simple threshold of sEV count in a blind test, classification of cancer vs. healthy samples is achieved with high sensitivity and specificity.

Wever et al. explore the use of different types of patient-friendly material, including urine, for the detection of ovarian cancer by methylation and copy number analysis. Upon continued development, DNA-based testing in cervical scrapes and urine could aid ovarian cancer diagnosis.