In this presentation, the Dr. John Stricker discusses the use of circulating tumor DNA (ctDNA) testing in colorectal cancer patients to guide treatment decisions. The presentation includes discussions on the sensitivity and specificity of ctDNA testing and its potential impact on treatment strategies. Several case studies are presented, highlighting the challenges and considerations when interpreting ctDNA results, especially in the context of adjuvant chemotherapy decisions for stage two colorectal cancer patients. The speaker emphasizes the need for careful evaluation and monitoring of ctDNA status to make informed treatment choices and discusses ongoing research in this area.