In a daytime television exclusive, legendary actress, author and humanitarian Valerie Harper joins The Doctors for her first on-camera interview following her announcement of terminal brain cancer. Her extremely rare form of brain cancer, known as leptomeningeal carcinomatosis, affects the meninges of the brain. Dr. Ronald Natale, the Medical Director of the Clinical Lung Program at Cedars-Sinai Medical Center in Los Angeles, explains how targeted therapy is used to identify specific mutations in a brain tumor.