The Intergroup Trial E2197 reported that Oncotype DX identifies women with hormone positive, HER2-negative breast cancer with 0-3 positive axillary nodes who are at a 3-4 fold increase in the risk of relapse despite standard chemotherapy and hormonal therapy. These results were presented at the 2007 annual meeting of the American Society of Clinical Oncology (ASCO) and it involved 465 women who had received chemotherapy and hormonal therapy for hormone receptor-positive early breast cancer. Of these women, 262 were node-negative and 203 had between one and three involved axillary lymph nodes.
• The Oncotype DX Recurrence Score was a significant predictor of recurrence risk in both node-negative and node-positive women.
• Women with a low Recurrence Score had excellent outcomes after standard therapy.
• Women with an intermediate or high Recurrence Score had a two- to threefold increase in recurrence risk compared to women with a low Recurrence Score.
On March 8th, 2010 another study was published in the Journal of Clincal Oncology. The researchers collected information from 1,231 women who participated in the ATAC (Arimidex, Tamoxifen, Alone or in Combination) study. The study enrolled postmenopausal women with early, hormone receptor-positive breast cancer. Study participants received hormonal therapy with either tamoxifen or Arimidex.
The Recurrence Score (RS) predicted the risk of distant cancer recurrence among women with node-negative and node-positive breast cancer.
NCCN has not yet changed its recommendations for Oncotype only for node negative disease. Nevertheless, two studies now suggests that the Oncotype DX test provides information about risk of distant cancer recurrence in both node-negative and node-positive, hormone-receptor positive breast cancer. Furthermore, Oncotype DX was predictive of distant recurrence risk among women treated with tamoxifen as well as women treated with Arimidex.
Medicare covers Oncotype in women with 1-3 + nodes. A 2012 analysis by Maumounas et al, also suggests that the test is beneficial in node positive women. 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. Many physicians use it for node + disease (http://www.drugs.com/clinical_trials/genomic-health-announces-results-clinical-survey-showing-oncotype-dx-changes-recommendations-women-8638.html).
With the exception of BCBS TEC, none of the professional or independent groups evaluated Oncotype DX for lymph node-positive breast cancer. BCBS TEC concluded that there is insufficient evidence to determine the clinical validity or utility of Oncotype DX as a predictor of breast cancer recurrence or response to adjuvant chemotherapy in patients with node-positive breast cancer.
Naoko Ishibe, et al, Evidence on Genomic Tests Use of Oncotype DX in Women with Node-Positive Breast Cancer PLoS Curr. 2011 July 21; 3: RRN1249
Tuma, Rabiya S, Breast oncotype predicts in node-positive disease Oncology Times UK:October 2012 – Volume 9 – Issue 10 – p 7
Conlon N et al, Is There a Role for Oncotype Dx Testing in Invasive Lobular Carcinoma?Breast J. 2015 Sep-Oct;21(5):514-9.