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 node-positive, hormone receptor-positive breast cancer and a low Oncotype DX Recurrence Score.
You can learn more about OncoyypeDX at www.MyTreatmentDecision.com
Albain KS, Barlow WE, Shak S et al. Prediction of 10-year chemotherapy benefit and breast cancer-specific 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.
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