Prof. Nicholas Turner and colleagues presented findings from ZEST, the first Phase 3 trial evaluating MRD-guided therapy in breast cancer using circulating tumor DNA (ctDNA) surveillance.

Key Takeaways:

  • High recurrence detection – 50% of patients were already metastatic at ctDNA+ detection.
  • TNBC recurrence pattern – Most ctDNA+ cases appeared within 6 months post-treatment, highlighting the early recurrence nature of TNBC.
  • Trial limitations – Broad eligibility criteria led to low randomization rates, resulting in early termination.
  • Potential therapeutic impact – While not powered for efficacy, the study hinted at longer recurrence-free intervals with niraparib vs. placebo.

These findings support earlier ctDNA testing in TNBC to improve timely intervention and patient outcomes.