For this round of case based panel discussions, Dr. Jack West is joined by Drs. Heather Wakelee and Caroline McCoach.Dr. Wakelee is Professor of Medicine in the Division of Medicine and Oncology at Stanford University Medical Center.Dr. McCoach is Assistant Professor in the Thoracic Medical Oncology Division of the UCSF Helen Diller Comprehensive Cancer Center in San Francisco, California.In this series, the doctors discuss a series of cases related to EGFR Mutations. For EGFR mutations treated with Tagrisso, and with progression while on treatment, what is the role of repeat biopsy?For more, please visit http://cancerGRACE.org/. To join the conversation, visit https://cancergrace.org/forum.