Performance of the multi-target hepatocellular carcinoma blood test: Design and rationale of the ALTUS study

BACKGROUND: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death in the United States and worldwide. HCC screening among patients at elevated risk is associated with improved early detection and overall survival, but current ultrasound-based screening strategies are challenged by low adherence and suboptimal sensitivity. Blood-based screening tests have the potential to enhance adherence and improve early-stage HCC detection if they can demonstrate favorable performance compared with ultrasound-based screening. Here we present the design and rationale for ALTUS (Alternative to Ultrasound), a prospective, longitudinal, multicenter study in the United States to investigate the performance of the multi-target HCC blood test (mt-HBT) for the detection of HCC in a screening population. METHODS: Adults with liver cirrhosis or chronic hepatitis B infection will be enrolled to undergo standard-of-care screening imaging and concurrent blood collection for the mt-HBT. All participants will undergo contrast-enhanced CT or MRI imaging with central radiology LI-RADS assessment as the reference method to determine HCC status. Participants without an identified malignancy will undergo a second screening visit and blood collection, and longitudinal clinical and imaging data will be collected up to 18 months from enrollment. The primary study objectives are to demonstrate that the mt-HBT is non-inferior to ultrasound for early-stage HCC sensitivity and to assess mt-HBT HCC specificity. The secondary objective is to assess mt-HBT overall sensitivity. RESULTS: ALTUS is in progress with readout of the primary analysis expected in 2025. CONCLUSIONS: This prospective head-to-head comparison of the mt-HBT versus ultrasound will provide novel data regarding the performance and utility of the mt-HBT for HCC screening.