The Role of Next‐Generation Sequencing in Enabling Personalized Oncology Therapy

Early breast cancer diagnosis is typically followed by surgical resection to remove the tumor, after which adjuvant therapy is administered for up to five years, or until relapse and presentation of metastatic disease. Archived tissue from the primary tumor is the initial source of material for NGS applications, in particular the identification of genomic driver mutations. In some cases, core needle biopsies may be collected at relapse or during later lines of therapy, but this occurs in a minority of patients and typically samples only one metastatic site. NGS on DNA from fresh biopsies is useful for real time assessment of genomic drivers, or to identify resistance mechanisms that may arise on prior therapies. In contrast to tissue, blood collection for NGS of ctDNA is more straightforward than obtaining fresh biopsies and has many conceptual uses over the natural history of breast cancer. Pending development of sensitive and specific methodologies, ctDNA could be used for screening and early detection. Analysis after surgery may be useful in detecting residual tumor DNA and identifying patients at high risk of relapse. Finally, in the metastatic setting ctDNA could be used to identify genomic drivers, dissect heterogeneity of disease, and in longitudinal monitoring to detect resistance mutations.This article is protected by copyright. All rights reserved