Identification of minimal residual disease using the TRACKseq (CloneSight) test for ultrasensitive ctDNA detection to anticipate late relapse in early breast cancer

BREAST CANCER RESEARCH — 2025 

Comino-Méndez I., et al.

This prospective exploratory study evaluated a tumor-informed ctDNA assay for MRD detection in HR+ early breast cancer, showing potential for anticipating late relapse before clinical recurrence. 

Topics

Solid tumors · Breast cancer · MRD · TRACKseq

Expanded summary

This study included 20 HR+ early breast cancer patients who had completed at least five years of adjuvant endocrine therapy. Tumor-specific somatic variants identified through tissue sequencing were used to build a patient-informed ctDNA assay, using a multiplex PCR-based NGS workflow.

ctDNA was detected in 50% of patients who later relapsed, with positivity observed up to 68 months / 5.7 years before overt recurrence in this exploratory cohort. Among non-relapsed patients, ctDNA remained undetectable in 93% of cases, supporting the potential specificity of the approach.

For Altum, this article is highly relevant to the solid tumor roadmap because it demonstrates how tumor-informed ctDNA MRD monitoring may support long-term surveillance in early breast cancer. The results are promising but should be presented carefully as exploratory and requiring validation in larger cohorts. 

View article: https://doi.org/10.1186/s13058-025-02016-7