Most Early-Stage Breast Cancer Patients Can Safely Avoid Chemotherapy, According to Landmark TAILORx Results Presented at ASCO 2018 and Published in The New England Journal of Medicine

Seventy percent of early-stage breast cancer patients can safely forego
chemotherapy and use hormonal therapy alone (such as Arimidex®, tamoxifen or
Faslodex®), according to the long-awaited results of the landmark TAILORx (Trial
Assigning IndividuaLized Options for Treatment (Rx)) study presented at the 2018
American Society of Clinical Oncology (ASCO) Annual Meeting on June 3. The
largest-ever breast cancer treatment study, TAILORx is a prospective, randomized
clinical trial sponsored by the NCI and designed to more precisely define the
effect of chemotherapy for women with Oncotype DX Breast Recurrence Score®

Based on the TAILORx results, most patients with Breast Recurrence Scores of
0 to 25 – the majority of early-stage breast cancer patients – will not benefit
from chemotherapy. In women 50 and younger, those with Recurrence Scores
16 to 20 showed a modest (2%) chemotherapy benefit, 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. For all women with Recurrence Scores 26 to 100 regardless
of age, there was a clear and large chemotherapy benefit. These findings are
expected to set a new era in breast cancer treatment, since the Oncotype DX
Recurrence Score test can now be used to determine the precise magnitude of
chemotherapy benefit for each individual patient. As a result, many more women
should be able to pursue hormonal therapy alone, avoiding the negative side
effects of unnecessary chemotherapy, while the women who will benefit from
chemotherapy will be guided to potentially life-saving treatment.
The TAILORx trial was independently designed and led by the ECOG-ACRIN
Cancer Research Group (ECOG-ACRIN) with advocacy organizations playing
a major direct role in the design, implementation, and funding of the trial.
In the international trial, thousands of investigators in six countries enrolled
approximately 10,000 patients, more than 6,700 of whom were women with
Oncotype DX Recurrence Score results of 11 to 25. This primary study group was
randomized to receive hormonal therapy with or without chemotherapy, and
was followed for approximately nine years on average. It is estimated that about
260,000 women worldwide will be impacted by these landmark trial results.