Most patients with stage II colon cancer will be fine after surgery, with little risk that their cancer will come back.
But one in five will have cancer spread beyond their colon.
Better information about which patients will relapse could spare many from the risks of chemotherapy.
A new gene test announced at the 2011 Gastrointestinal Cancer Symposium in San Francisco helps provide answers to which patients are at highest risk and could help patients and their doctors make better decisions about follow-up chemotherapy after surgery.
ColoPrint, an 18 gene tumor tissue signature, found that three out of four patients with stage II colon cancer had only about a 5 percent risk of recurrence, very similar to stage I patients. For the remaining high risk patients, one in five (20 percent) had cancer return.
In a series of 135 patients with stage II colon cancer, ColoPrint identified
- 73 percent at low risk of recurrence. After a median 97 months of followup, only 5 percent experienced a relapse.
- 27 percent at high risk. During the 97 month follow-up, 20 percent had cancer return.
ColoPrint was developed by searching the whole genome for a fingerprint of genes that predicted recurrence from colon cancer. The study reported at the GI Symposium is the second one to validate the test. A third validation study of 600 patients is now underway at MD Anderson Cancer Center in Houston, with results expected later this year.
In a press briefing, surgeon Robert Rosenberg, MD, an assistant professor at the University Hospital of the Technical University in Munich, Germany said,
The ColoPrint gene expression test was the only significant factor that predicted the development of distant metastasis in our patient series, In this validation study, the performance of ColoPrint seemed to be independent of known clinical factors. ColoPrint was able to predict outcome in stage II patients, and this facilitates the identification of patients who may be safely managed without chemotherapy.
SOURCE: Rosenberg et al,, Independent validation of a prognostic genomic profile (ColoPrint) for stage II colon cancer (CC) patients, Abstract #358, 2011 Gastrointestinal Cancers Symposium.