The Oncotype DX colon cancer test, which is currently available for treatment planning in Stage II colon cancer, may also predict recurrence risk in Stage III colon cancer. These results were presented at the 2010 annual meeting of the American Society of Clinical Oncology.
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 provides important information for patients with Stage II colon cancer. 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. The Oncotype DX test provides information about recurrence risk.
To determine whether the Oncotype DX colon cancer test may also be useful for patients with Stage III colon cancer, researchers collected information from four large studies. The researchers evaluated the biological similarities and differences between Stage II and Stage III colon cancer.
The results indicated that although there are some differences between Stage II and Stage III colon cancer that warrant additional evaluation, there were notable similarities for most of the 375 genes studies and for the 12-gene Oncotype DX colon cancer Recurrence Score.
In a prepared statement, the lead author of the study said, “Earlier this year physicians began incorporating Oncotype DX into clinical practice for stage II colon cancer patients. We are now conducting additional research to evaluate this test for treatment planning in stage III disease, based on the similarities observed in this study.”
Reference: O’Connell MJ, Lavery IC, Gray RG et al. Comparison of molecular and pathologic features of stage II and stage III colon cancer in four large studies conducted for the development of the 12-gene colon cancer recurrence score. Presented at the 2010 annual meeting of the American Society of Clinical Oncology. June 4-8, 2010. Chicago, IL. Abstract 3503.