Translating Liquid Biopsy into Practice- The Promise and Challenges of Circulating Tumor Cells in Ovarian and Lung...

The increasing mortality from ovarian and lung cancers worldwide is largely due to late diagnosis and therapeutic resistance. Conventional biomarkers such as CA125 and CYFRA 21-1 lack the sensitivity or the specificity for monitoring real time disease progression or therapeutic response. This has prompted researchers to work on the development of relevant biomarkers that are minimally invasive for cancer diagnosis, prognosis and for therapeutic stratification. As such, liquid biopsies, which analyze tumor-derived components circulating in the blood including circulating tumor cells (CTCs), which are shed from primary or metastatic tumors into the bloodstream have emerged as a promising approach for detecting such cancers. This review critically analyzes the diagnostic and prognostic significance of CTCs in ovarian and lung cancers, highlighting technological advances, molecular characterization, and translational challenges associated with their clinical application. It briefly discusses the clinical utility of some biomarkers from liquid biopsies used in the diagnosis, prognosis as well as monitoring of ovarian and lung cancers with their detection methods. It highlights some of the relevant studies conducted in the field and finally it provides insights on the future of liquid biopsies. An extensive literature review analyzing papers between 2008 and 2026 was conducted using PubMed, Scopus, and Web of Science databases, that evaluated CTC detection methods, molecular profiling, and clinical outcomes in ovarian and lung cancer patients. Current literature reports that CTC enumeration and molecular characterization can provide significant insights into disease progression, therapeutic resistance and predict survival outcomes. Whilst the enrichment technologies such as CellSearch^®, ISET, and microfluidic platforms have enhanced detection sensitivity, variability in assay performance and lack of a clinical standardization impede proper implementation. CTCs represent a powerful liquid biopsy tool with potential to revolutionize cancer diagnostics and precision medicine. Integration of multi-omics profiling, CTC-derived organoids, and AI-driven analytical models may further enhance their clinical utility in guiding personalized treatment strategies for ovarian and lung cancer patients.