Exact Sciences Corp, Madison, Wis, announced the presentation of new data at the virtual 2020 San Antonio Breast Cancer Symposium (SABCS) building on the clinical value of the Oncotype DX Breast Recurrence Score test. These data highlight the role of the test in further individualizing treatment decisions in early breast cancer.
“These latest presentations, including data from the RxPONDER trial, further highlight the unique value of the Recurrence Score result in providing critical information to personalize and improve the quality of treatment decisions in node-negative and node-positive early breast cancer,” says Rick Baehner, MD, chief medical officer of Precision Oncology at Exact Sciences.
Five-year outcomes from ADAPT study show that not all clinically high-risk patients with node-negative or node-positive disease need chemotherapy
First efficacy results from the ADAPT study (4,691 patients) were presented at SABCS.[i] Patients were all considered candidates for chemotherapy by traditional parameters and were stratified using the Oncotype DX test and changes in the immunohistochemical prognostic marker Ki67 after three weeks of pre-operative anti-hormonal therapy. Patients with clinically high-risk node-negative disease, and node-positive disease with up to 3 positive nodes, were treated with anti-hormonal therapy alone if the Recurrence Score result was 0–11 or if the Recurrence Score result was 12-25 with a Ki67 response. This group of patients had, regardless of their age, favorable outcomes with anti-hormonal therapy alone, with 5-year distant disease-free survival of 96%.
Another analysis from the ADAPT trial also presented at SABCS evaluated 864 breast cancer patients who received neoadjuvant chemotherapy primarily based on their Recurrence Score result.[ii] These results from a large neoadjuvant trial showed that the Recurrence Score result is a strong predictor of response to chemotherapy as assessed by the rate of pathologic complete response (no residual invasive tumor).
ADAPT is one of the largest prospective, randomized studies in early-stage breast cancer and was conducted by the West German Study Group (WSG) in 80 centers across Germany. It utilized a pioneering trial design to assess individualization of (neo)adjuvant decision-making.
“Our study shows the unique value of the complementary biological information provided by the Oncotype DX test and sequential Ki67 testing. Risk stratification using the Recurrence Score result and changes in Ki67 after brief pre-operative anti-hormonal therapy allows us to identify those patients with node-negative or node-positive disease who can be spared the toxicity and side effects of chemotherapy without a negative impact on treatment outcome,” says Prof. Nadia Harbeck, Scientific Director of the WSG and Head of the Breast Centre at LMU Klinikum Munich (LMU), Germany. “This is especially important for patients who would be considered at high risk of relapse based on traditional clinical parameters.”
New patient-specific meta-analysis provides individualized estimates for both prognosis and absolute chemotherapy benefit in node-negative breast cancer
A new patient-specific meta-analysis of data from more than 10,000 patients with node-negative disease assessed individualized estimates of distant recurrence risk and absolute chemotherapy benefit based on the integration of the Recurrence Score result with clinicopathologic features.[iii]
This analysis builds on the practice-changing results from the TAILORx study, which prospectively defined the groups of patients who will and will not benefit from chemotherapy.[iv]
The meta-analysis was conducted by the ECOG-ACRIN Cancer Research Group (ECOG-ACRIN) and was presented in an oral session at SABCS by lead author Joseph A. Sparano, MD, associate director for clinical research at Albert Einstein Cancer Center and associate chair for clinical research in the department of oncology at Montefiore Health System in New York, and leader of the TAILORx study for the ECOG-ACRIN Cancer Research Group. The data was published concurrently in the December 2020 issue of the Journal of Clinical Oncology.
The patient-specific meta-analysis estimates will initially be made available to physicians in the United States, starting in December 2020, as an online educational tool called RSClin. The tool provides a more individualized prediction of absolute chemotherapy benefit that can enhance treatment decisions, particularly for patients whose Recurrence Score result is close to the TAILORx defined cut-off point of 25. By presenting the data in a new, easy-to-understand, visual format, RSClin empowers physicians with information that may be used to facilitate treatment conversations and decision-making with patients.
“As confirmed in TAILORx, for the great majority of patients, treatment based on the Recurrence Score result alone is clear,” says Sparano. “The RSClin tool, which now incorporates data from TAILORx to reflect contemporary treatment outcomes, provides individualized estimates for both risk of distant recurrence and absolute chemotherapy benefit and continues to demonstrate the role of TAILORx in informing early-stage breast cancer treatment.”
ECOG-ACRIN conducted the analysis primarily with funding from the National Cancer Institute. Mention of commercial products does not imply endorsement by the United States government. Additional support was provided by the Breast Cancer Research Foundation, the Komen Foundation, and the Breast Cancer Research Stamp issued by the United States Postal Service.
For more information, visit Exact Sciences.
[i] Harbeck, N. et al. Oral Presentation: GS4-04. San Antonio Breast Cancer Symposium; December 2020.
[ii] Kuemmel, S. et al. Oral Presentation: GS4-03. San Antonio Breast Cancer Symposium; December 2020.
[iii] Sparano, J. et al. Oral Presentation: GS4-09. San Antonio Breast Cancer Symposium; December 2020.
[iv] Sparano JA, Gray RJ, Makower DF, et al. Adjuvant Chemotherapy Guided by a 21-Gene Expression Assay in Breast Cancer. N Engl J Med. 2018;379(2):111-121. doi:10.1056/NEJMoa1804710