Applications of ctDNA testing to monitor and detect residual disease in breast cancer

Expert Rev Mol Diagn. 2025 Jun;25(6):263-274. doi: 10.1080/14737159.2025.2498545. Epub 2025 Apr 28.

Abstract

Introduction: In recent years, circulating tumor DNA (ctDNA) has emerged as a promising method for detection of minimal or molecular residual disease (MRD) among patients with breast cancer.

Areas covered: In this narrative review, we provide a summary of currently available studies assessing use of ctDNA in detection of MRD in patients after completion of curative therapy. Additionally, we discuss limitations of present studies, future considerations, and an overview of ongoing trials evaluating the clinical utility of MRD-directed therapy interventions.

Expert opinion: While the clinical utility of MRD-directed therapy guidance remains under investigation, collective data from studies overwhelmingly confirm the prognostic value of ctDNA status across various stages and subtypes of breast cancer. Results from ongoing clinical trials in the coming years will provide more clarity on the overall clinical benefit of MRD-directed interventions for breast cancer patients.

Keywords: breast cancer; ctDNA; liquid biopsy; minimal residual disease; molecular residual disease.

Publication types

  • Review

MeSH terms

  • Biomarkers, Tumor* / blood
  • Biomarkers, Tumor* / genetics
  • Breast Neoplasms* / blood
  • Breast Neoplasms* / diagnosis
  • Breast Neoplasms* / genetics
  • Breast Neoplasms* / therapy
  • Circulating Tumor DNA* / blood
  • Circulating Tumor DNA* / genetics
  • Female
  • Humans
  • Neoplasm, Residual* / diagnosis
  • Prognosis

Substances

  • Circulating Tumor DNA
  • Biomarkers, Tumor