Presented by: Christina Lockwood, PhD, Professor, University of Washington; Medical Director of Clinical Diagnostics, Brotman Baty Institute for Precision Medicine
Covered by: Hannah Abrams, MD
“Precision Oncology 101” begins with understanding the armamentarium of tests and targets in modern precision oncology. Dr. Christina Lockwood, professor at the University of Washington and medical director of clinical diagnostics at the Brotman Baty Institute for Precision Medicine, reviews the broad types of genetic variants to detect, potential uses of testing, and considerations for choosing a genetic test.
Beginning from the point of biopsy, she explains, clinicians should think about whether a given assay will work on limited tissue samples. For example, she describes an assay of lung adenocarcinoma: if the cellularity of the biopsy specimen is too low, a test may miss significant mutations. By contrast, ultra-sensitive ctDNA assays are helpful for tumors which are challenging to biopsy, or which need serial monitoring, and can provide information about the overall disease, rather than just the specific specimen submitted. In ovarian cancer, she explains, plasma cell-free DNA monitoring can identify BRCA2 “reversion” mutations that lead to treatment resistance.
Dr. Lockwood also describes the benefits of genetic testing in predicting treatment response, such as in the case of NTRK gene fusions and larotrectinib, and in identifying somatic mutations to diagnose hereditary cancer predispositions. To sum up the future of precision oncology, she predicts that we will profile nearly all cancers within the next 5 years, and that more cancers will be both defined and monitored via sequencing in the near future.