Natera, Inc. announced new data being presented by the company and its collaborators on the use of the Signatera® personalized molecular residual disease (MRD) technology at the 2021 European Society for Medical Oncology (ESMO) Congress, taking place September 1621, 2021. In three new studies, Natera will present the real-world clinical performance of Signatera in esophageal and gastric cancers, the power of ctDNA dynamics for assessing treatment response in uveal melanoma and the correlation of CHIP mutations with patient outcomes. This study used Signatera for the detection and quantification of ctDNA in a prospective real-world cohort of 886 plasma samples from 269 patients with gastroesophageal cancer. Serial time points were collected in a subset of patients to monitor ctDNA levels after curative intent therapy. Analysis showed tumor-informed ctDNA status is highly predictive of relapse in patients with stage I-IV disease, with ctDNA detected in 93.3% of samples at baseline. Uveal melanoma is a rare type of melanoma of the eye, associated with frequent liver metastases. This study of 127 mUM patients used a custom ctDNA assay for the evaluation of tebentasfusp therapy. Baseline ctDNA levels significantly correlated with tumor burden, and by week 9, 70% of evaluable patients showed ctDNA reduction associated with greater mean tumor shrinkage. For tebentafusp, ctDNA reduction appeared more correlated with overall survival than RECIST response. Buffy coat samples derived from 2484 patients diagnosed with colorectal, breast, lung and other solid cancers were analyzed for the presence of CHIP mutations, which were detected in 16% of patients, with the majority having a single mutation. As expected, the frequency of CHIP increased with age and reached 20% in patients above 60 years, who were also more likely to have multiple CHIP variants compared to the younger patients. Although CHIP mutations are not tumor-derived and should not be used to monitor MRD burden, the presence of CHIP in MRD-positive cases was associated with poor patient outcomes and reduced time to recurrence.