Dr Priya Rastogi speaks to ecancer about findings from the NSABP B-59 study evaluating circulating tumour DNA as a biomarker in early-stage triple-negative breast cancer treated with neoadjuvant therapy with or without atezolizumab.

Detection of ctDNA after neoadjuvant therapy, prior to surgery, was strongly associated with residual disease and significantly worse distant recurrence-free outcomes.

Patients with detectable ctDNA were far less likely to achieve a pathologic complete response, highlighting its value as an early indicator of treatment resistance.

Additionally, baseline ctDNA levels correlated with tumour burden, increasing with higher tumour stage and nodal involvement. These results reinforce ctDNA as a powerful, non-invasive biomarker for risk stratification and early response assessment.

Overall, Dr Rastogi highlights that this study supports the integration of ctDNA monitoring into clinical decision-making to better identify high-risk patients and guide treatment strategies in triple-negative breast cancer.