Genomic Health: New Validation Shows Oncotype DX Breast Recurrence Score Test Predicts Clinical Response to Neoadjuvant Hormonal Therapy to Improve Surgical Outcomes in Certain Patients with Large Tumors

Ten Oncotype DX® studies presented at the 40th San Antonio Breast Cancer Symposium

Geneva, Switzerland, December 11, 2017 / B3C newswire / -- Genomic Health, Inc. today announced highlights from new data presentations with the Oncotype DX Breast Recurrence Score® test at the 2017 San Antonio Breast Cancer Symposium (SABCS).

“These latest presentations further our understanding of breast cancer biology across the continuum of the disease and highlight the unique value of the Oncotype DX® test in providing critical information to personalize and improve the quality of treatment decisions in both the adjuvant and neoadjuvant settings,” said Calvin Chao, Vice President of Global Medical Affairs at Genomic Health.

Analyzing tumor biology with Oncotype DX can help guide treatment decisions prior to breast cancer surgery  

Neoadjuvant systemic therapy such as chemotherapy and hormonal therapy can shrink tumor size and allow breast conserving surgery (BCS) for patients diagnosed with hormone receptor positive (HR+) large tumors (≥2cm) who may otherwise be advised to undergo a mastectomy. However, chemotherapy comes with its many debilitating side effects and, in some patients, does not provide improved surgical outcomes over hormonal therapy. Identifying patients whose tumors may not respond to chemotherapy is difficult using traditional parameters and as a result some patients receive chemotherapy treatment in this setting, yet unfortunately they do not derive any benefit.

Core needle biopsy samples from approximately 300 postmenopausal patients with HR+, HER2-, node negative invasive breast cancer enrolled in the randomized Phase 3 NEOS study were analyzed to determine clinical response to six months of hormonal therapy before surgery based on Recurrence Score® results.

The analysis(1) showed that Recurrence Score results are significantly associated with clinical response to hormonal neoadjuvant therapy (p<0.001). Specifically, findings suggest that, for patients with a Recurrence Score result below 18, treatment with neoadjuvant hormonal therapy alone could be an effective treatment strategy. Such patients could thus potentially avoid chemotherapy without reducing their chances of successful BCS.

“This important validation study demonstrates that analyzing tumor biology with Oncotype DX in the neoadjuvant setting can help guide treatment decisions,” said Prof. Hiroji Iwata, Principal Study Investigator, Department of Breast Oncology, Aichi Cancer Center Hospital, Nagoya, Japan. “In particular, patients with a low Recurrence Score result tend to have higher clinical response rate with neoadjuvant hormonal therapy, which makes it possible to shrink the tumor size and achieve breast conserving surgery leading to better cosmetic outcomes whilst limiting the impact of treatment side effects on their quality of life.”

New results from large registry with 10-year follow up show excellent outcomes for patients with low Recurrence Score results treated with hormonal therapy alone

In this study(2) from Clalit Health Services, the largest health services organization in Israel, medical records of more than 1,500 patients with node negative breast cancer or with micro metastases tested between January 2006 and December 2009 were examined to verify given treatment and subsequent outcomes. The findings showed that use of chemotherapy was aligned with Recurrence Score results. Patients who had been diagnosed with HR+, node negative breast cancer and who had Recurrence Score results of less than 18, the vast majority of whom (98.2% or 632) were treated with hormonal therapy alone, had excellent outcomes with 10-year Kaplan Meier estimates of distant recurrence of 3.9% and breast cancer specific survival rate of 98.1%.  

“This important analysis with long-term follow up shows that patients with low Recurrence Score results can be treated with hormonal therapy alone and indicates that withholding chemotherapy is possible in those with intermediate risk and Recurrence Score results up to 25,” said Prof. Salomon Stemmer, Lead investigator of the study, Department of Oncology, Davidoff Center, Rabin Medical Center affiliated to Tel Aviv University, Israel. “The genomic information provided by the Oncotype DX test is important in order to identify patients who can be spared the toxicity of chemotherapy.”

New data reinforce specific value of examining tumor biology with Oncotype DX in older women

This analysis(3) from the prospective West German Study Group’s (WSG) PlanB trial examined Oncotype DX Breast Recurrence Score results in patients aged 70 years and greater versus those under 70. It then evaluated disease free survival (DFS) in both groups. For patients with higher risk tumors (Recurrence Score result over 25) treated with chemotherapy, results showed comparable DFS rates regardless of which age bracket they were in.

The findings reinforce the value of the Oncotype DX Breast Recurrence Score test for older patients to identify more accurately those who would derive benefit from chemotherapy.

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