Beyond Blood: ctDNA from Urine, CSF, and Body Fluids Offers Distinct Diagnostic Advantages
This Nature Reviews Clinical Oncology paper examines ctDNA analysis from non-blood sources including urine, cerebrospinal fluid, and pleural or peritoneal fluid. These alternative sources can complement plasma ctDNA by offering higher tumor DNA fractions in anatomically relevant compartments, such as CSF for brain tumors and urine for bladder cancer. The review addresses technical considerations for assay development and identifies clinical scenarios where non-blood ctDNA has distinct advantages over standard plasma testing.
The original study
Circulating tumour DNA - looking beyond the blood.
- Authors
- Tivey A, Church M, Rothwell D, Dive C, Cook N
- Journal
- Nature reviews. Clinical oncology
- Type
- Journal Article, Review, Research Support, Non-U.S. Gov't
- PMID
- 35915225
Original abstract
Over the past decade, various liquid biopsy techniques have emerged as viable alternatives to the analysis of traditional tissue biopsy samples. Such surrogate 'biopsies' offer numerous advantages, including the relative ease of obtaining serial samples and overcoming the issues of interpreting one or more small tissue samples that might not reflect the entire tumour burden. To date, the majority of research in the area of liquid biopsies has focused on blood-based biomarkers, predominantly using plasma-derived circulating tumour DNA (ctDNA). However, ctDNA can also be obtained from various non-blood sources and these might offer unique advantages over plasma ctDNA. In this Review, we discuss advances in the analysis of ctDNA from non-blood sources, focusing on urine, cerebrospinal fluid, and pleural or peritoneal fluid, but also consider other sources of ctDNA. We discuss how these alternative sources can have a distinct yet complementary role to that of blood ctDNA analysis and consider various technical aspects of non-blood ctDNA assay development. We also reflect on the settings in which non-blood ctDNA can offer distinct advantages over plasma ctDNA and explore some of the challenges associated with translating these alternative assays from academia into clinical use.