# Circulating Tumor Cells: Isolation, Preclinical Models, and Clinical Applications for Personalized Cancer Therapy

## TL;DR

This review discusses how circulating tumor cells can be isolated and used in preclinical models to guide personalized cancer treatments.

## Contribution

The paper highlights recent technological advances and preclinical models that enable CTCs to be used for individualized drug testing.

## Key findings

- Improved CTC isolation methods now allow for detailed molecular profiling and ex vivo analysis.
- CTC-derived models like organoids and xenografts can replicate patient-specific tumor heterogeneity.
- Integration of AI and multi-omics could enhance the clinical use of CTCs for personalized therapy.

## Abstract

Circulating tumor cells (CTCs) represent a powerful, minimally invasive window into tumor biology and disease evolution. Technological progress over the past decade has markedly improved the ability to isolate, preserve, and interrogate viable CTCs, transforming them from simple prognostic markers to functional tools for precision oncology. Advances in microfluidic platforms, immunomagnetic enrichment, aptamer-based capture, and nanostructured interfaces have expanded the efficiency and fidelity of CTC recovery, enabling comprehensive molecular profiling and ex vivo analysis. These innovations have paved the way for the development of CTC-derived preclinical models, including xenografts, organoids, and chorioallantoic membrane assays, which recapitulate patient-specific tumor heterogeneity and support individualized drug-sensitivity testing. In this review, we summarize current technologies for CTC isolation, outline recent achievements in functional and pharmacological characterization, and discuss the translational impact of CTC-derived models. We further identify persistent challenges and emerging opportunities, highlighting how integration of multi-omics platforms, artificial intelligence, and standardized workflows may accelerate the clinical implementation of CTC-guided personalized therapy.