Some stage-2 colon cancer patients may benefit from the use of chemotherapy after surgery, according to a retrospective study led by Ludwig Stanford’s Michael Clarke. The study is published in the current issue of The New England Journal of Medicine along with two editorials describing its significance. Clarke and his colleagues categorized colon cancer patients based on the presence or absence of a protein called CDX2, which is found in mature colon cells and can be detected with a clinical-grade test. They found that about 4% of people with colon cancer have tumors that don’t express CDX2. In an initial study of patients with any stage of colon cancer, they found that only about 41% of those with cells lacking CDX2 lived disease-free for five years after treatment, compared to 74% of those with CDX2 in their cancer cells. But in a subsequent, larger analysis, the researchers also identified another important distinction between patients whose tumors express CDX2 and those whose tumors do not, particularly among people with stage-2 disease: About 91% with CDX2-negative cancers who received chemotherapy after surgery lived disease-free for five years, as opposed to 56% of those who did not. Previous studies, which did not distinguish between CDX2-positive and CDX2-negative cancers, suggested that chemotherapy provided little additional benefit to stage-2 colon cancer patients.
A complete news release from Stanford University School of Medicine detailing the findings can be accessed at this site.