"In this study, investigators utilized Sysmex Inostics' highly sensitive plasma NGS technology based on the Safe-Sequencing System (Safe-SeqS) to confirm the results of mammography findings in early stage breast cancer patients. While mammography is the current standard of care for breast cancer(BC) screening it is not always 100% informative, and in cases of abnormal findings, follow-up is performed via tissue biopsy to confirm/refute the presence of cancer. However, single site tissue analysis can be technically challenging, with false negatives due to tissue heterogeneity, failure to capture genomic profile of metastases, and limited tumor content. Investigators analyzed circulating tumor DNA (ctDNA) in an attempt to represent more faithfully the genomic profile across and within sites of disease.
Targeted NGS was performed for TP53 and PIK3CA - two of the most commonly mutated genes in breast cancer - on matched blood and tissue biopsy specimens collected from 56 women presenting with BIRADS 4c/5 mammography results and subsequent diagnosis of primary breast cancer. Plasma NGS revealed mutations in either or both PIK3CA and TP53 in 10 of 29 patients, with 4 mutations detected in the plasma that were not identified in the tissue. The investigators concluded that mutations in ctDNA can be readily detected using a highly sensitive plasma sequencing method in breast cancer patients at mammography, suggesting that early ctDNA testing can provide critical clinical information that may improve patient diagnosis.
As Dr. Emilio Alba, Principal Investigator and UGC Medical Oncology Director at H. Regional Univ. and Hospital Virgen de la Victoria of Malaga commented on the findings, "Importantly, these results show value for the complementary assessment of plasma and tissue genetic alterations to accompany abnormal mammography findings in order to more accurately characterize the disease status of early stage breast cancer patients. Clearly, mutations in ctDNA can be readily detected using a highly sensitive and focused plasma sequencing method at mammography and these promising findings open the possibility of improving the diagnosis of early-stage breast cancer patients in routine care. We look forward to further evaluating the power of highly sensitive plasma NGS testing to gain insight into clonal diversity/expansion, monitor recurrence, guide treatment decisions, and evaluate therapy efficacy."
Monday June 4, 1:15 to 4:45 PM, Hall A, Poster Session Category: Tumor Biology; Subcategory: Molecular Diagnostics and Imaging; Board #186; Abstract No. 12073. Plasma sequencing of ctDNA in early stage breast cancer as part of the screening process.