Multiparametric Circulating Tumor Cell Analysis to Select Targeted Therapies for Breast Cancer Patients.

A Franken ,Mahdi Rivandi,Natali Schölermann,Ellen Honisch,Francesco Marass,Frederic Dietzel,Tanja Fehm,Hannah Asperger,Natalia Krawczyk,Niko Beerenwinkel,Bernadette Jaeger,Dieter Niederacher,Charlotte Proudhon,Nikolas H Stoecklein,Hans Neubauer,Emmanuelle Jeannot,Liwen Yang,Bianca Behrens,Jan‐Philipp Cieslik ,F Reinhardt ,Irene Espósito

doi:10.3390/cancers13236004

Abstract

Simple SummaryLiquid biopsies may act as a dynamic tool for identification of targets for precision therapy while circumventing limitations of tissue biopsies. In opposite to most liquid biopsy-related studies that analyze limited patient material for only one parameter, this study is based on a longitudinal and multiparametric analysis of circulating tumor cells (CTCs). A metastatic breast cancer patient was followed over a period of three years and analyses of the genome, RNA profiling, and in vitro drug testing on cultured CTCs were performed in a unique manner. We show that combining the strengths of multiple technologies for analysis yielded maximum information on the ongoing disease and, eventually, allowed choosing an effective therapy, which led to a massive reduction in CTC numbers. This approach provides a concept for future detailed longitudinal and multiparametric CTC analyses.Background: The analysis of liquid biopsies, e.g., circulating tumor cells (CTCs) is an appealing diagnostic concept for targeted therapy selection. In this proof-of-concept study, we aimed to perform multiparametric analyses of CTCs to select targeted therapies for metastatic breast cancer patients. Methods: First, CTCs of five metastatic breast cancer patients were analyzed by whole exome sequencing (WES). Based on the results, one patient was selected and monitored by longitudinal and multiparametric liquid biopsy analyses over more than three years, including WES, RNA profiling, and in vitro drug testing of CTCs. Results: Mutations addressable by targeted therapies were detected in all patients, including mutations that were not detected in biopsies of the primary tumor. For the index patient, the clonal evolution of the tumor cells was retraced and resistance mechanisms were identified. The AKT1 E17K mutation was uncovered as the driver of the metastatic process. Drug testing on the patient’s CTCs confirmed the efficacy of drugs targeting the AKT1 pathway. During a targeted therapy chosen based on the CTC characterization and including the mTOR inhibitor everolimus, CTC numbers dropped by 97.3% and the disease remained stable as determined by computer tomography/magnetic resonance imaging. Conclusion: These results illustrate the strength of a multiparametric CTC analysis to choose and validate targeted therapies to optimize cancer treatment in the future. Furthermore, from a scientific point of view, such studies promote the understanding of the biology of CTCs during different treatment regimens.

Highlights

In the last decades, targeted therapy has become the preferred treatment approach in many cancers
circulating tumor cells (CTCs) counts per 7.5 mL of blood were between 94 and approximately 50,000 (Table 1)
We show a workflow for whole exome sequencing (WES) of amplified DNA from low CTC numbers to identify clinically relevant mutations, combined with a detailed multiparametric liquid biopsy analysis that can personalize and optimize patient therapy based on liquid biopsies

Summary

Introduction

In the last decades, targeted therapy has become the preferred treatment approach in many cancers. The genomic profile of biopsy tissues provides a picture limited to a single point in space and time, and may under-represent intratumoral heterogeneity [2] Such factors limit the predictive utility of tissue biopsies, worsened still by the continuous evolution of the tumor cells in response to endogenous and exogenous selective pressures [3]. To overcome this challenge, the idea of deriving information about the primary tumor (PT) or metastatic lesions from liquid biopsies, which may act as a dynamic diagnostic tool, is an appealing concept [4]. The analysis of liquid biopsies, e.g., circulating tumor cells (CTCs) is an appealing diagnostic concept for targeted therapy selection In this proof-of-concept study, we aimed to perform multiparametric analyses of CTCs to select targeted therapies for metastatic breast cancer patients. From a scientific point of view, such studies promote the understanding of the biology of CTCs during different treatment regimens

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Conclusion