CIPHER Study: Pilot Study to Study the Role of ctDNA in Triple Negative and HER2 Positive Early Stage

SignateraTM is a custom-built circulating tumor DNA (ctDNA) test for treatment monitoring and molecular residual disease (MRD) assessment in patients previously diagnosed with cancer. The Signatera methodology is personalized and tumor-informed, providing each individual with a customized blood test tailored to fit the unique signature of clonal mutations found in that individual's tumor tissue. This maximizes accuracy for detecting the presence or absence of disease in a blood sample, even at levels down to a single tumor molecule in a tube of blood. Signatera is intended to detect and quantify how much cancer is left in the body, to improve prognosis and help optimize treatment decisions, based on the tissue-informed testing of mutations.

In participants, undetectable ctDNA at fourteen days will be in the observation arm (observation defined as TNBC: No adjuvant chemotherapy. Participants may complete checkpoint inhibitor from neoadjuvant setting; HER2 positive BC: Completed one year of anti-HER2 therapy from the neoadjuvant setting). No investigational drugs will be used. Samples of ctDNA will be collected at time points described in the study arm.