In a study published last month in the New England Journal of Medicine, researchers identified a new marker for recurrence in stage II and stage III colon cancer. We sat down with Dr. Laura Porter to breakdown this new marker, the study, and what this news could mean for you.
Along with predicting who will recur, the new marker CDX2 - a biomarker of mature colon cells - was shown to predict who will respond to treatment. This is the first biomarker that has been proven to be both predictive and prognostic.
Researchers examined a large database looking for actionable markers (those for which a clinical-grade diagnostic test is already developed). They examined 16 genes and the one that met their criteria was CDX2. The CDX2 protein is seen in mature colon cell and is depleted in colon tumors.
The study found that colon tumors that are CDX2-negative have a higher risk of recurrence then CDX2-positive tumors. CDX2-negative tumors are often associated with an increased likelihood of aggressive features, including advanced stage, poor differentiation, and vascular invasion and BRAF mutation.
The researchers looked at a total of 669 patients with stage II colon cancer and 1,228 patients with stage III colon cancer. Adjuvant chemotherapy was associated with a higher rate of disease-free survival in both stage II colon cancer, 91% with chemotherapy vs. 56% with no chemotherapy and stage III colon cancer, 74% with chemotherapy vs. 37% with no chemotherapy in the CDX2-negative tumors.
In stage II colon cancer, the overall survival was 40% with CDX2-negative tumors and 70% with CDX2-positive tumors.
So What's the Big Deal?
This is important because stage III colon cancers are always treated with chemotherapy, while stage II are not. Until now, few - if any - markers that indicate a high risk of recurrence could also predict a response to treatment.
The researchers stated:
“Our results indicate that patients with stage II or stage III CDX2-negative colon cancer might benefit from adjuvant chemotherapy and that adjuvant chemotherapy might be a treatment option for patients with stage II CDX2-negative disease, who are commonly treated with surgery alone. Given the exploratory and retrospective design of our study, these results will need to be further validated.”
It is important to note that the CDX2 marker only applies to colon cancer, not rectal cancer. We will continue to keep you updated as more data becomes available.
Don’t forget, the Colon Cancer Alliance serves as a source of information about colon health. If you have additional questions about screening or are in need of support, please contact our free Helpline at (877) 422-2030. We’re here to help!