Discussing a ctDNA-Guided Treatment Switch With Patients

Rebecca Shatsky, MD, describes telling a patient with a clean scan but a new ESR1 mutation on ctDNA that treatment needs to change, saying she sets that expectation from the start of testing rather than presenting it as a surprise. She has not adopted routine testing on a fixed schedule and instead personalizes frequency based on tumor markers. Carol Tweed, MD, says she cannot identify a patient for whom she would not apply the SERENA-6 strategy once available, describing a patient who could not bear weight due to a femur lesion as the kind of clinical disaster earlier action could prevent. Dr. Shatsky adds a cost perspective from a recent debate, estimating the strategy could cost the United States health care system $75 million to $350 million depending on testing frequency, supporting a personalized monitoring interval over routine testing every 2 months for every patient.