59P Primary tumour and circulating tumour cell (CTC) copy number alterations (CNAs) in triple negative breast cancer (TNBC) patients (pts) treated with neoadjuvant chemotherapy (NAC)

Approximately 60% of pts with early-stage TNBC who undergo NAC without attaining pathologic complete response (pCR) will eventually relapse. Here we assessed the relationship between primary tumor (t-CNAs) and CTC-CNAs and clinical outcome in TNBC pts at the time of initial diagnosis and following NAC. CNA analysis was performed by the targeted NGS IonAmpliSeq Comprehensive Cancer Panel on pre-NAC tumor specimens, and low-pass whole genome...