ANGLE plc announced that University Medical Centre Hamburg-Eppendorf has published results of new work undertaken in patients with brain metastasis demonstrating use of the company's Parsortix system in the isolation of circulating tumour cells. In addition, the research investigated the role of two proteins, CD74 and CD44, in the development of brain metastasis. Liquid biopsy from peripheral blood is a particularly attractive solution in brain cancer because of the difficulty, medical complications and cost associated with taking a tissue biopsy from the brain. The characterisation of metastatic tumour cells can be crucial in helping to inform personalised treatment decisions, but, because of the serious risks involved, most patients with brain metastasis will never undergo a tissue biopsy unless undergoing surgical tumour resection. Historically, detection of CTCs from peripheral blood in brain metastasis has been hampered by the blood-brain-barrier which results in fewer CTCs in peripheral blood compared to other metastatic sites and, because these CTCs have a more mesenchymal state, they are poorly detected using antibody-based systems. In this study, 44 patients with primary breast cancer, non-small cell lung cancer and melanoma with subsequent brain metastases were screened for CTCs using the Parsortix system. CTCs were detected in 50% of breast cancer patients, 50% of NSCLC patients and 36% of melanoma patients. CTC positivity rates were superior when compared to previous studies into cancer brain metastases which utilised other CTC enrichment technologies, including the leading antibody-based system where positivity rates of 20-22% in breast cancer and 12.5% in NSCLC have been reported. Brain metastases are the most common type of brain tumour accounting for 88% of all new cases. The incidence of cancer brain metastases is increasing as new therapeutics, advanced imaging, and improved screening have led to increased survival following a primary diagnosis of cancer with approximately 200,000 new cases of brain metastases being diagnosed in the United States each year. This study further confirms the utility of the Parsortix system for the isolation and characterisation of CTCs in brain metastases and that a Parsortix-based blood test may provide additional medical information to inform treatment decisions that could otherwise only be obtained by a highly invasive tissue biopsy of the patient's brain.