03. 06. 2018 | Back to news overview

Landmark TAILORx Results Demonstrate the Oncotype DX Breast Recurrence Score® Test Definitively Identifies the majority of Women with Early-stage Breast Cancer Who Receive No Benefit from Chemotherapy

The Trial Assigning IndividuaLized Options for Treatment (Rx), or TAILORx, successfully defined the benefit of chemotherapy in early-stage breast cancer patients with Oncotype DX Breast Recurrence Score® results of 11 to 25. The long-awaited results of the TAILORx study, the largest ever breast cancer treatment trial, sponsored by the National Cancer Institute (NCI), and led by the ECOG-ACRIN Cancer Research Group (ECOG-ACRIN), provided definitive evidence that the Oncotype DX Breast Recurrence Score test identified 70 percent of early-stage breast cancer patients who receive no benefit from chemotherapy, and can be effectively treated with endocrine therapy alone. Additionally, the trial established that chemotherapy may provide life-saving benefit to 30 percent of patients.

The TAILORx results will be published today in TheNew England Journal of Medicine in conjunction with a presentation during the Plenary Session at the 2018 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago.

"TAILORx provides the most definitive answer about how to treat women with Oncotype DX Recurrence Scores of 11 to 25, as well as 0 to 10," said lead author Joseph A. Sparano, M.D., associate director for clinical research at the Albert Einstein Cancer Center and Montefiore Health System in New York City and vice chair of the ECOG-ACRIN Cancer Research Group.  "The results provide an unprecedented level of precision and highest level of evidence supporting the use of this test to guide adjuvant chemotherapy use in this population, which accounts for about one-half of all breast cancers."

About 50 percent of all breast cancer patients diagnosed worldwide each year have hormone-receptor positive, HER2-negative, node-negative cancer. The TAILORx study definitively established that chemotherapy may be spared in about 70 percent of these patients, including all women older than 50 with Breast Recurrence Score® results of 0 to 25 and all women age 50 or younger with Breast Recurrence Score results of 0 to 15.

Importantly, 30 percent of early-stage breast cancer patients will derive benefit from chemotherapy, including women of any age with Breast Recurrence Score results of 26 to 100, and in women younger than 50, where a modest (2 percent) benefit from chemotherapy was observed with Breast Recurrence Score results of 16 to 20, which gradually grew as scores increased up to and above 25. This important finding reveals a new level of precision of chemotherapy benefit for younger patients that only the Oncotype DX® test can provide.

"TAILORx, as well as the completed NSABP B-20 Oncotype DX study, are unparalleled in their design to define who does, and who does not, benefit from chemotherapy," said Steven Shak, M.D., chief scientific officer and chief medical officer, Genomic Health. "The long-term TAILORx results provide the highest level of evidence for Oncotype DX, allowing physicians to now tell every patient, with precision, what their magnitude of chemotherapy benefit will be."

The TAILORx trial was independently designed and conducted by ECOG-ACRIN under the sponsorship of the NCI, part of the National Institutes of Health. All major cancer clinical research groups with trial sites in the United States, Canada, Ireland, Peru, New Zealand and Australia participated in the study. Investigators used the Oncotype DX Breast Recurrence Score test on every patient to assign treatment or randomization in order to determine whether chemotherapy would be beneficial or not. The four research groups are the Alliance for Clinical Trials in Oncology, Canadian Trials Group, ECOG-ACRIN Cancer Research Group, NRG Oncology and SWOG.

TAILORx participants with Breast Recurrence Score results from 0 to 10 were treated with endocrine therapy alone based on the prior results from the NSABP B-20 study, which showed no opportunity for chemotherapy benefit. TAILORx participants with Breast Recurrence Score results from 26 to 100 were treated with chemotherapy plus endocrine therapy based on the prior results from the NSABP B-20 study, which showed an absolute benefit of chemotherapy greater than 20 percent.

To more precisely define the effect of chemotherapy for women considered to be at intermediate risk for recurrence, 6,711 women with Oncotype DX Breast Recurrence Score results of 11 to 25, the primary study group in TAILORx, were randomized to receive endocrine therapy with or without chemotherapy. These randomized patients comprised two-thirds of all patients enrolled in TAILORx and were followed by the investigators for approximately nine years on average. In total, 10,273 patients enrolled in TAILORx between 2006 and 2010.