For years, researchers have looked into liquid biopsy as a potentially useful tool to help Health Care Providers assess a patient’s response to treatment, monitor cancer recurrence and even detect targets for precision therapies. Since the approval of alpelisib in mid-2019, PIK3CA mutation has become a high interest target for genomic testing in patients with HR+/HER2- advanced breast cancer.  In fact, with the PIK3CA frequency rate observed in approximately 40% of patients with HR+/HER2- aBC- testing should be in every Pathologist’s armament for genomic profiling.

 As a leader in cancer diagnostic testing we often get cases with sub-optimal tissue specimen which, unfortunately, causes the test to fail. It’s heartbreaking. We know how difficult it can be for patients to endure a biopsy and yet, our technology is reliant on the integrity of the sample. For cases such as these, liquid biopsy, also known as circulating tumor DNA (ctDNA), is particularly useful to help match patients with optimal treatment using a simple blood draw, a minimally invasive procedure as compared to a tissue biopsy.

For patients with HR+/HER2- advanced breast cancer, detection of PIK3CA mutation is now available with PIK3CA Mutation Companion Diagnostic- Plasma, using ctDNA. This can have a major impact on breast cancer management; to be able to find a mutation that allows for treatment initiation without the requirement for a tissue biopsy. Although genomic profiling using tumor tissue definitely remains the gold standard when suitable archival tissue is available, when there is insufficient breast tissue or if the tissue is decalcified, testing by plasma is a terrific option for patients.

Liquid biopsy testing for cancer is continuing to evolve and we are starting to see a lot of promise in the clinical setting. PIK3CA Mutation CDx by Tissue or Plasma provides options for appropriate patients that require the next step for their management of advanced stage breast cancer.

Learn more from our podcast:
News With Neo: PIK3CA Mutation CDx

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About Lawrence M. Weiss, MD

Chief Medical Officer

About Lawrence M. Weiss, MD

Chief Medical Officer

Dr. Weiss received his BS summa cum laude and MD summa cum laude from the University of Maryland. He completed a residency in Anatomic Pathology at the Brigham and Women’s Hospital and a fellowship in Surgical Pathology at Stanford University Medical Center. He was previously an Assistant Professor of Pathology at Stanford, President of the Medical Staff, and Chairman of Pathology at the City of Hope. He is the author of over 500 papers and book chapters, as well as over a dozen books, including an AFIP Lymph Node Fascicle, Applied Immunohistochemistry, Lymph Nodes, and Knowles’ Hematopathology. His laboratory discovered the first molecular evidence linking the Epstein-Barr virus with Hodgkin Lymphoma. He has won numerous awards, including the Benjamin Castleman, Arthur Purdy Stout, and the United States-Canadian Academy of Pathology Young Investigator Award, and has delivered more than 250 national and international talks in Pathology, including several named lectureships. He is on the editorial board of ten scientific journals, and is a past President of the Los Angeles Society of Pathologists. He has been listed in the book The Best Doctors in America since 1994. Dr. Weiss’s diagnostic interests lie in lymph node pathology, adrenal pathology, solid tumor pathology, and immunohistochemistry.

These articles reflect the views of a group of experienced practitioners in subspecialty practice, with the goal to provide practical and useful guides to a specific diagnosis or problem area.