Oncotype DX Test and Node Positive Br Ca
You may be familiar with the Oncotype DX test which has been available for approximately 5 years. This test has been a major help to women with node-negative, ER positive breast cancer and their doctors as they decide whether chemotherapy would be a useful part of treatment. At last week's meeting in San Antonio, results of a study with node positive women were announced and suggest that this test may also be valuable for this group. Anything that helps us better individualize treatment is progress, and certainly no one wants to undergo chemotherapy if it is not necessary or helpful.
Here is a summary:
Oncotype Dx® Predicts Chemotherapy Benefit in Node-positive Breast Cancer
Among women with node-positive, hormone receptor-positive breast cancer, use of the Oncotype DX® test identifies a subset of women who do not appear to benefit from adjuvant (post-surgery) anthracycline-based chemotherapy. These results were presented at the 2009 San Antonio Breast Cancer Symposium and were also published in Lancet Oncology. Oncotype DX is a genomic test that previously has been shown to predict the likelihood of cancer recurrence in women with early-stage, estrogen receptor-positive breast cancer that is treated with hormonal therapy. Women with a low risk of recurrence may derive little benefit from chemotherapy.
Oncotype DX evaluates the activity of 21 genes from a sample of the patient's cancer to determine the patient's Recurrence Score. The Recurrence Score ranges from 0 to 100, with a higher score indicating a greater risk of recurrence. Oncotype DX has been added to U.S. medical guidelines for early-stage breast cancer. Oncotype DX was initially validated among women with node-negative breast cancer, but the test also appears to provide important information about women with node-positive breast cancer. To further assess the test among women with node-positive, hormone receptor-positive breast cancer, researchers evaluated information from 367 patients. Some patients received adjuvant therapy with tamoxifen [Nolvadex®] alone, and some received tamoxifen plus anthracycline-based chemotherapy.
• The addition of chemotherapy to tamoxifen significantly improved breast cancer survival among women with a high Oncotype DX Recurrence Score (RS≥31).
• The addition of chemotherapy did not improve breast cancer survival among women with a low Recurrence Score.
These results suggest that anthracycline-based chemotherapy may not benefit women with nodepositive, hormone receptor-positive breast cancer and a low Oncotype DX Recurrence Score.
Albain KS, Barlow WE, Shak S et al. Prediction of 10-year chemotherapy benefit and breast cancerspecific survival by the 21-gene Recurrence Score (RS) assay in node-positive, ER-positive breast cancer—An update of SWOG-8814 (INT0100). Presented at the 32nd CTRC-AACR San Antonio Breast Cancer Symposium. December 9-13, 2009. San Antonio, TX. Abstract 112.
Albain KS, Barlow WE, Shak S et al. Prognostic and predictive value of the 21-gene recurrence score assay in postmenopausal women with node-positive, oestrogen-receptor-positive breast cancer on chemotherapy: a retrospective analysis of a randomised clinical trial. Lancet Oncology [early online publication]. December 10, 2009.