A survey of oncologists suggests that the Oncotype DX colon cancer test changes treatment recommendations for 29 percent of patients with Stage II colon cancer. These results will be presented at the 2012 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 selected women with early-stage 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 became available for patients with Stage II colon cancer in 2010. 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.
Previous research has demonstrated that the Oncotype DX colon cancer test provides information about the risk of recurrence among patients with Stage II colon cancer. Researchers are now evaluating how this information affects treatment decisions.
In the current study, researchers surveyed US oncologists who had experience with the Oncotype DX colon cancer test. All participating oncologists had ordered the test for at least three patients with Stage II colon cancer, and were asked to provide treatment information for the most recent patient. The study is ongoing, and the current, preliminary analysis includes information from 92 oncologists.
These results build upon previous studies of the Oncotype DX colon cancer test by demonstrating that use of the test can influence treatment decisions for Stage II colon cancer.
 Gray RG, Quirke P, Handley K et al. Validation study of a quantitative multigene reverse transcriptase-polymerase chain reaction assay for assessment of recurrence risk in patients with stage II colon cancer. Journal of Clinical Oncology. 2011; 29(35):4611-9.
 Cartwright T, Chao C, Lopatin M, Bentley T, Broder M, Change E. Effect of Oncotype® DX Colon Cancer Test Results on Treatment Recommendations in Patients with Stage II Colon Cancer: Preliminary Results. Paper presented at: 2012 Gastrointestinal Cancers Symposium; January 19-21, 2012; San Francisco, CA. Abstract 398.