S1-Leitlinie: Tumorgenetik – Diagnostik im Kontext maligner Erkrankungen

The Diversity of Liquid Biopsies and Their Potential in Breast Cancer Management

Analyzing blood as a so-called liquid biopsy in breast cancer (BC) patients has the potential to adapt therapy management. Circulating tumor cells (CTCs), extracellular vesicles (EVs), cell-free DNA (cfDNA) and other blood components mirror the tumoral heterogeneity and could support a range of clinical decisions. Multi-cancer early detection tests utilizing blood are advancing but are not part of any clinical routine yet. Liquid biopsy analysis in the course of neoadjuvant therapy has potential for therapy (de)escalation.Minimal residual disease detection via serial cfDNA analysis is currently on its way. The prognostic value of blood analytes in early and metastatic BC is undisputable, but the value of these prognostic biomarkers for clinical management is controversial. An interventional trial confirmed a significant outcome benefit when therapy was changed in case of newly emerging cfDNA mutations under treatment and thus showed the clinical utility of cfDNA analysis for therapy monitoring. The analysis of PIK3CA or ESR1 variants in plasma of metastatic BC patients to prescribe targeted therapy with alpesilib or elacestrant has already arrived in clinical practice with FDA-approved tests available and is recommended by ASCO. The translation of more liquid biopsy applications into clinical practice is still pending due to a lack of knowledge of the analytes' biology, lack of standards and difficulties in proving clinical utility.

[Current trends in liquid biopsy and diagnostics-contributions from ASCO and ESMO 2022]

BACKGROUND

Liquid biopsy is a promising new diagnostic tool that is already used in clinical practice for multiple tumor entities and which also has great potential for head and neck cancer. Herein, the authors discuss a selection of publications from the American Society of Clinical Oncology (ASCO) and European Society of Medical Oncology (ESMO) meetings in 2022.

OBJECTIVE

Relevant publications are evaluated and summarized.

METHODS

Using a databank inquiry, abstracts from the 2022 ASCO and ESMO conferences regarding liquid biopsy and related diagnostics for head and neck squamous cell carcinoma were collected. Work without relevant data and statements of intent were not included. Duplicate articles across conferences were only quoted once. A total of 532 articles were screened, 50 articles were selected for further review, and 9 articles were selected for presentation.

RESULTS

Six articles on cell- and RNA-based liquid biopsy and three articles on more general diagnostic tools in the treatment of head and neck cancer are presented. The results are discussed in relation to current treatment standards.

CONCLUSION

Multiple studies show promising results for the use of circulating tumor DNA (ctDNA) for treatment surveillance in head and neck cancer. Integration into clinical practice will depend on larger study cohorts and sinking costs.