An innovative approach to detect circulating tumor cells

In cancer research, circulating tumor cells (CTCs) were identified as the main drivers of metastasis. They are vital for early detection and prevention of metastasis during cancer treatment. Even though continuous progress in research offers more and more tools to combat cancer, we still lack a proper arsenal of therapeutics. Especially in tumors with close to no targeting options, like triple-negative breast cancer, early detection is often the main difference between successful and failed therapy. When such tumors are detected too late, they may have already produced plenty of CTCs, likely causing metastasis, which is the primary reason for tumor-associated deaths. Detecting those CTCs early on could substantially impact therapy outcomes and the 5-year survival rate. In our study, we developed and evaluated a reliable and affordable CTC screening method based on flow cytometry and 5-aminolevulinic acid (5-ALA) staining. We successfully established a circulation model for 5-ALA and CTCs research and demonstrated that the method can detect an average of 11 ± 3.3 CTCs out of 10,000 peripheral blood mononuclear cells, representing as low as approximately 0.1 % with a reasonable number of false positive events. Additionally, we present initial results on a theranostic approach using 5-ALA converted to protoporphyrin IX. The outcomes of this study might contribute significantly to the further development of CTC detection and the overall detection and treatment of cancer.