Presymptomatic detection of metastatic breast cancer using Non-Invasive Prenatal Testing (NIPT)

Occult maternal malignancies presenting with copy-number gains and losses across multiple chromosomes at NIPT have been reported.1,2 We present a 37-year-old pregnant woman with a history of breast cancer, diagnosed 15 years prior. NIPT was performed at 15/40. Genome-wide analysis of cell-free DNA from consecutive samples showed multiple copy-number gains (1q, 7, 8q and 20) and losses (3q and 12). Localised amplification within chromosome region 17q12 (containing ERBB2) was noted. The copy-number changes were considered likely to be maternal in origin and acquired. The patient had no clinical symptoms and further investigations failed to identify a malignancy. Microarray analysis of amniotic fluid confirmed a normal fetal karyotype. The pregnancy continued and a healthy baby was delivered by caesarean at full term. Repeat NIPT collected 7 weeks post-delivery demonstrated a decrease in the intensity of the copy-number changes observed during pregnancy, however amplification of 17q12 was still noted. PET-CT and subsequent MRI demonstrated an anterior mediastinal mass which was resected and diagnosed as HER2 positive metastatic breast cancer in two lymph nodes. While pre-symptomatic primary malignancies detected at NIPT have been described, this is the first report of a pre-symptomatic re-occurrence of a previous malignancy detected by an aberrant NIPT result. References1.Bianchi DW, Chudova D, Sehnert AJ, et al. Noninvasive prenatal testing and incidental detection of occult maternal malignancies. JAMA 2015; 314: 162–9.2.Amant F, Verheecke M, Wlodarska I, et al. Presymptomatic identification of cancers in pregnant women during noninvasive prenatal testing. JAMA Oncol 2015; 1: 814–9.