June 8, 2011

Oncotype DX Identifies Stage II Colon Cancer with Higher Risk of Recurrence

By Anonymous User

Among patients with Stage II colon cancer, the 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 2011 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 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 study, the Oncotype DX Recurrence Score and other factors were evaluated among patients with Stage II colon cancer who participated in the CALGB 9581 study.

  • Even after accounting for factors such as stage, grade, number of lymph nodes examined, and mismatch repair (MMR) protein status, the Recurrence Score was a significant predictor of recurrence risk.
  • The researchers also evaluated the Recurrence Score in a subset of patients for whom traditional factors such as grade do not provide prognostic information (patients with T3 stage II cancer and intact MMR protein function). Once again, the Recurrence Score was able to identify patients who had a high risk of cancer recurrence: five-year risk of recurrence was more than 20% among patients with the highest Recurrence Scores.

These results confirm that the Oncotype DX colon cancer test provides new information about recurrence risk in patients with Stage II colon cancer. The test may help guide treatment decisions by identifying patients with more aggressive disease.

Reference: Venook AP, Niedzwiecki D, Lopatin M et al. Validation of a 12-gene colon cancer recurrence score (RS) in patients (pts) with stage II colon cancer (CC) from CALGB 9581. Paper presented at: 2011 Annual Meeting of the American Society of Clinical Oncology; June 3-7, 2011; Chicago, IL. Abstract 3518.

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

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