Clinical relevance of liquid biopsy in breast cancer: update in 2020

ABSTRACT

Introduction

Breast cancer is the most common cancer in women worldwide. Despite the development of targeted therapies that have significantly improved survival, effective breast cancer evaluation is still challenging due to the complexity of this disease. Liquid biopsy might allow the noninvasive real-time monitoring of the tumor course and response to therapy.

Areas covered

This review summarizes the latest advances on the various circulating analytes used as liquid biopsy (circulating tumor cells and tumor DNA, and more recently extracellular vesicles) for breast cancer work-up. Several studies have shown that in breast cancer, liquid biopsy can be used to predict disease progression or relapse and to monitor the treatment response. Moreover, circulating analytes are more easily accessible than tissue biopsies and might represent a powerful source of specific knowledge.

Expert opinion

The new evidence coming from the increasing number of clinical trials, and the continuous improvements in the technologies to isolate these tumor-derived analytes should strengthen the role of liquid biopsy in the clinic for personalized medicine of breast cancer.

KEYWORDS:

• Breast cancer
• liquid biopsy
• circulation tumor cells
• circulating DNA
• extracellular vesicles

Article highlights

• Each analyte has its specificity and interest for answering independent and different questions.

• CTCs can be considered as a reliable liquid biopsy analyte to provide prognostic and predictive clinical information.

• The recent advances in CTC analysis provide insights into their predictive role concerning sensitivity or resistance to therapies, and CTC changes during treatment can serve as a pharmacodynamic monitoring tool.

• cfDNA and ctDNA could represent a good prognostic and predictive biomarker in BCa.

• EVs might be used not only for cancer evaluation, prognosis, and for acquiring knowledge about the disease but also as a new drug delivery strategy.

• For personalized medicine, it would be interesting to compute all data obtained with these different liquid biopsy analytes to obtain a precise tumor profile.

Acknowledgments

The authors thank Dr Elisabetta Andermarcher for assistance with her comments and proofreading that greatly improved the manuscript.

Declaration of interest

C Alix-Panabières received honorarium from Menarini for consultancies. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.