Among patients with Stage II colon cancer, use of the newly available Oncotype DX colon cancer test provides information about the risk of cancer recurrence and may help guide treatment decisions. These results were presented at the 2010 ASCO Gastrointestinal Cancers Symposium.

Gene expression profiling explores the patterns of genes that are active in tumor cells. Studies suggest that gene expression may provide important information about prognosis or likely response to treatment in several types of cancer. For example, among women with early-stage, estrogen receptor-positive breast cancer, the Oncotype DX breast cancer test has been shown to predict the likelihood of cancer recurrence and the likelihood of benefit from chemotherapy. As a result, the test has been added to medical guidelines for early-stage breast cancer.

A similar test may provide important information for patients with Stage II colon cancer. Stage II colon cancer refers to cancer that extends through the wall of the colon but has not invaded lymph nodes or spread to distant parts of the body. Many patients with this stage of disease have good outcomes with surgery alone, and routine adjuvant (post-surgery) chemotherapy is not currently recommended for Stage II colon cancer. Chemotherapy may, however, be considered for Stage II patients with a higher risk of cancer recurrence.

In the current analysis, the Oncotype DX colon cancer Recurrence Score and other factors were evaluated in 657 patients with Stage II colon cancer treated with surgery alone.

• Risk of cancer recurrence varied by the Recurrence Score as well as the number of lymph nodes examined. Patients with higher Recurrence Scores had a higher risk of cancer recurrence. Patients also had a higher risk of recurrence if they had fewer lymph nodes examined.

The researchers concluded: “Number of nodes examined and [Recurrence Score] are independent predictors of recurrence in stage II colon cancer following surgery, and both should be considered when assessing individual recurrence risk.”

The Oncotype DX colon cancer test is the first commercially available gene expression test for the assessment of recurrence risk in Stage II colon cancer.

Reference: Gray RG, Quirke P, Handley K et al. Correlation of number of nodes examined and the 12-gene colon cancer recurrence score with recurrence in stage II colon cancer patients from QUASAR. Presented at the 2010 ASCO Gastrointestinal Cancers Symposium. January 22-24, 2010, Orlando, FL. Abstract 331.

Tags: Adjuvant (I-III, A-C) Colon Cancer, Colon Cancer, News Tips and Features