The only definitive way to diagnose most brain cancers is by surgical biopsy, a potentially dangerous procedure that is sometimes not even an option. Researchers led by Ludwig Johns Hopkins’ Chetan Bettegowda and Christopher Douville reported in an August issue of Cancer Discovery a multianalyte test that can accurately detect brain cancers using small quantities of cerebrospinal fluid (CSF). They also demonstrated that combining multiple biomarkers significantly improves the specificity of such tests. Their workflow, named CSF-BAM, simultaneously identifies B cell and T cell receptor sequences, aneuploidy—abnormal numbers of chromosomes in cells, a common feature of advanced cancers—and mutations using amplification of both strands of DNA obtained from CSF samples. The researchers validated CSF-BAM using 209 samples from patients with high-grade gliomas, medulloblastomas, brain metastases, and central nervous system lymphomas. The workflow detected the most common and aggressive brain tumors—accounting for 129 samples—with a sensitivity of 81%. None of the 30 CSF-BAM assays run on samples from people without brain cancer generated a false positive. Aside from detecting brain cancers, the researchers note, the test also provides potentially useful information about the genetics and immune microenvironment of brain tumors.
Detection of human brain cancers using genomic and immune cell characterization of cerebrospinal fluid through CSF-BAM
Cancer Discovery, 2025 August 25