New Test Predicts Colon Cancer Recurrence

For the first time, a test can predict which patients with stage 2 colon cancer are more likely to have a recurrence.

The Oncotype DX colon cancer test, similar to the currently available test for breast cancer, analyzes the expression of a specific set of genes to come up with a recurrence score—information that can be used to determine which patients should receive chemotherapy (5-FU and leucovorin-based therapy) after surgery. Researchers noted, however, that they were not able to validate a separate score meant to predict which patients would benefit from chemotherapy.

After analyzing 761 genes from more than 1,800 patients, researchers identified 12 genes to predict recurrence and another six genes to measure treatment response. A predictive test is needed in stage 2 colon cancer because up to 80 percent of patients will be cured by surgery, but there’s no method for identifying whom these patients are, said researcher David Kerr, MD, of the University of Oxford, at a press briefing prior to the meeting. Other than stage, there are no other well-established prognostic factors for colon cancer.

The test for predicting treatment benefit is being refined, Kerr said. Investigators are currently looking at a new set of genes that would allow doctors to know which tumors will respond to chemotherapy and which patients can safely forego the extra treatment without compromising survival.

Genomic Health, the company that markets the Oncotype DX breast cancer test, said it plans to make the 12-gene Oncotype DX colon cancer test available in early 2010.