Among women with node-positive, estrogen receptor-positive breast cancer, the Oncotype DX test provides information about expected recurrence risk and survival after treatment with chemotherapy and hormone therapy. These results were presented at the 2012 Breast Cancer Symposium.
Among women with early-stage breast cancer, the expression, or activity, of certain genes has been linked with the likelihood of cancer recurrence. Oncotype DX is a genomic test that predicts risk of recurrence among selected women with early-stage breast cancer. The test evaluates 21 genes in a sample of tumor tissue and generates a recurrence score. The information provided by the recurrence score can help guide treatment decisions.
The Oncotype DX test was originally developed for use in women with estrogen receptor (ER)-positive, node-negative breast cancer, but the test has also been shown to predict outcomes in women with ER-positive, node-positive breast cancer.
To further explore use of the test among women with node-positive breast cancer, researchers assessed more than 1000 women who had participated in a clinical trial known as NSABP B-28. All of the women in the current analysis had ER-positive breast cancer that was treated with chemotherapy and hormone therapy.
- Disease-free survival (survival without a recurrence or new cancer) varied significantly depending on a woman’s recurrence score. Ten-year disease-free survival was 76% among women with a low recurrence score, 57% among women with an intermediate recurrence score, and 48% among women with a high recurrence score.
- The recurrence score also provided information about overall survival. Ten-year overall survival was 90% among women with a low recurrence score, 75% among women with an intermediate recurrence score, and 63% among women with a high recurrence score.
- The recurrence score remained an important predictor of long-term outcomes even after accounting for factors such as age, tumor size, tumor grade, number of positive lymph nodes, and type of surgery.
These results indicate that the Oncotype DX recurrence score predicts risk of recurrence and survival outcomes among women with ER-positive, node-positive breast cancer treated with chemotherapy and hormone therapy. High-risk women may benefit from more extensive treatment or enrollment in a clinical trial.
Reference: Mamounas EP, Tang G, Paik S et al. Prognostic impact of the 21-gene recurrence score (RS) on disease-free and overall survival of node-positive, ER-positive breast cancer patients (pts) treated with adjuvant chemotherapy: Results from NSABP B-28. Presented at the 2012 Breast Cancer Symposium. September 13-15, 2012. San Francisco, CA. Abstract 1.
Posted September 14, 2012