ETS was significantly associated with long-term outcome in patients with KRAS wild-type mCRC treated first-line with chemotherapy plus cetuximab. Validation in prospective trials is required to assess the value of this on-treatment marker in the clinical decision-making process.
Piessevaux, H., Buyse, M., Schlichting, M., Van Cutsem, E., Bokemeyer, C., Heeger, S., & Tejpar, S. (2013). Use of early tumor shrinkage to predict long-term outcome in metastatic colorectal cancer treated with cetuximab. Journal of Clinical Oncology, 31(30), 3764-3775. https://doi.org/10.1200/JCO.2012.42.8532 (Original work published 2013)