Abstract Although mammograms have been a useful tool since the first half of the 20th century and have an acceptable sensitivity (87%) in the general population, that drops to <50% in women with dense breasts making it an ineffective screening tool in this population. Cell free DNA (cfDNA) has proven to be an inadequate alternative in this population, and while MRI is acceptable, it is expensive. Astrin Biosciences has developed a blood-based assay that detects circulating tumor cells (CTCs) at a high sensitivity to serve as an alternative screening method to mammography in breast cancer early detection, specifically in women with high-density breasts. Astrin’s technology integrates holographic imaging, machine learning, and microfluidics to identify CTCs in the blood stream. Omics analysis can then be performed on the collected cells to further differentiate patients with cancer from matched healthy controls. Astrin has initiated a small cohort study to investigate the sensitivity and specificity of CTC detection in women with early-stage breast cancer. Astrin’s small cohort study, including patients with ductal carcinoma in situ, stage 1, and stage 2 breast cancer patients, demonstrated > 85% sensitivity and specificity. A large cohort study is being conducted to validate these preliminary results. The small cohort study demonstrates the ability of Astrin Bioscience’s platform to detect cancer cells at an early stage, particularly in breast cancer. This technology will drastically increase the effectiveness of breast cancer screening modalities available to patients. Additionally, since it is a blood-based assay, it can be performed at shorter intervals in high-risk populations than mammograms which require a full patient appointment. Citation Format: Justin M. Drake, Kaylee J. Kamalanathan, Catalina Galeano-Garces, Nathaniel Bristow, Nicholas Heller, Mahdi Ahmadi, Olivia Hedeen, Alexa Hesch, Grant Schaap, Joel Hapke, Jeff Miller, Ivo Babris, Tuan Le, Tony Clacko, Jiarong Hong, Badri Konety, Jayant Parthasarathy. Circulating tumor cell-based early detection of breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6078.