Thanks for a great discussion so far! If anyone has a particular topic that he or she would like to address, please feel free to post a question directly or just send me a message!
For today and tomorrow, I'd like to continue our discussion on how this new data on CDX2 fits into our current and future approaches to adjuvant chemotherapy in stage II colon cancer.
As noted by Dr. Sargent and Dr. Dalerba yesterday, there are a variety of molecular features (such as MSI-H, TP53, BRAF, CIMP-H and now CDX2) that can be used to stratify tumors into subtypes. In addition, stage II disease, per the 2010 AJCC guidelines, is now subdivided into IIA, IIB, and IIIC based on tumor invasion (T3 vs. T4 primary). A variety of other clinicopathologic features (such as poor differentiation, bowel perforation or obstruction, lymphovascular or perineural invasion, inadequately sampled nodes, indeterminate or positive surgical margins, and high pre-operative CEA levels) have also been associated with "high risk" stage II disease. Furthermore, there are several adjuvant chemotherapy options, including oxaliplatin, 5-FU, and capecitabine, that have been studied in stage II and III disease.