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12-Gene Colon Cancer Recurrence Score Identifies Stage II Colon Cancer With Higher Risk of Recurrence
Background

Among patients with stage II colon cancer, gene expression profiling provides information about the risk of cancer recurrence and may help guide treatment decisions for this patient population. Results of CALGB 9581, which evaluated a 12-gene colon cancer assay in patients with stage II colon cancer, were presented by Venook and colleagues1 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 including breast and 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. Stage II colon cancer may be cured by surgical resection alone and most oncologists do not advocate adjuvant chemotherapy for patients with stage II colon cancer without features of a higher risk of recurrence. Although the overall prognosis after a curative resection is generally excellent, about 20% of patients with resectable stage II colon cancer will experience a recurrence and die from the disease. Higher-than-average risk for recurrence includes those with anatomic features such as tumor adherence to adjacent structures, perforation, complete obstruction, or with biologic characteristics such as aneuploidy, high S-phase analysis, or deletion of 18q.2

In the current study, the 12-gene colon cancer Recurrence Score and other factors were evaluated among patients with stage II colon cancer who participated in the CALGB 9581 study.1 Study findings included:

  • 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). 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.
The authors concluded that these results confirm that the 12-gene colon cancer assay provides new information about recurrence risk in patients with stage II colon cancer and suggest the test may help guide treatment decisions by identifying stage II patients with more aggressive disease.1

The 12-gene colon cancer assay is marketed as Oncotype DX® Colon Cancer Assay by Genomic Health, Inc., Redwood City, CA.

ManageCRC.com Commentary

ManageCRC.com reported the preliminary results of a similar study (QASAR) of a 20-gene colon cancer assay in 2009 http://managecrc.com/Articles/ArticleReader.aspx?article=119&page=1. The current study by Venook and colleagues1 has reported that the 12-gene colon cancer assay is a valid method of predicting recurrence in patients with stage II colon cancer. Having a well-validated prognostic tool helps optimize treatment plans by identifying those patients for whom chemotherapy is needed and sparing those with a low risk of recurrence from the physical, economic and quality of life burden of systemic chemotherapy.

References

  1. 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. J Clin Oncol. 2011; 29 (suppl): Abstract 3518. Abstract can be accessed at http://www.asco.org/ASCOv2/Meetings/Abstracts?&vmview=abst_detail_view&confID=102&abstractID=77737
  2. National Cancer Institute. Colon Cancer Treatment (PDQ®). Stage II Colon Cancer. Retrieved from http://www.cancer.gov/cancertopics/pdq/treatment/colon/HealthProfessional/page7


Article Created On : 6/24/2011 11:22:05 AM             Article Updated On : 6/24/2011 11:22:05 AM