The TAILORx results provide definitive answers

"Adjuvant chemotherapy may now be guided with an unprecedented level of evidence and precision" said lead author Joseph A. Sparano, MD. "The 21-gene assay ... [can] identify the 70% of women with no chemotherapy benefit, and the others where chemotherapy may be life-saving." Know with confidence who will benefit from chemotherapy and who will not.1-4

The largest randomized adjuvant breast cancer trial ever conducted, the Trial Assigning IndividuaLized Options for Treatment (Rx) (TAILORx) was independently led by ECOG-ACRIN Cancer Research Group with sponsorship from the National Cancer Institute.

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As presented at ASCO 2019, a new analysis of TAILORx confirms the original, definitive conclusions reported previously with additional detail on clinical risk, focusing on patients with early-stage breast cancer who are age 50 years or younger.

See the new analysis on NEJM from ASCO 2019

The publication describes clinical outcomes for women with a high Recurrence Score (RS) result 26-100, who received adjuvant chemotherapy (CT) plus endocrine therapy (ET) in the TAILORx trial, a population expected to have a high distant recurrence rate with endocrine therapy alone. In this secondary analysis, among 1389 women with early breast cancer and a high RS result of 26-100, who received adjuvant CT, the estimated proportion free from distant recurrence at 5 years was 93%. These patients with RS results 26-100 had consistently better outcomes with CT+ET than what would be expected with ET alone.

Read the article on JAMA

Participating cancer research groups included the Alliance for Clinical Trials in Oncology, NCIC-Clinical Trials Group, NRG Oncology, and SWOG.

In early stage ER+, HER2-, N0 breast cancer, who benefits from chemotherapy?

25% of patients with a low Recurrence Score (RS) result (0–25) had high clinical risk* and would have been overtreated without the RS result

*High clinical risk: Grade 1, > 3 cm; Grade 2, > 2 cm; Grade 3, > 1 cm.
43% of patients with a high Recurrence Score (RS) result (26–100) had low clinical risk** and would have been undertreated without the RS result

**Low clinical risk: Grade 1, ≤ 3 cm; Grade 2, ≤ 2 cm; Grade 3, ≤ 1 cm.

No more “Intermediate” Recurrence Score results

  • No statistically significant difference in invasive disease-free survival was found among patients with Recurrence Score (RS) results 11–25, proving that they do not benefit from chemotherapy2
  • TAILORx expanded on previous data, confirming excellent outcomes at 9 years for patients with RS results 0–25 treated with endocrine therapy alone1,2
  • For RS results 26–100, there was a significantly higher event rate despite treatment with adjuvant chemotherapy2

*Driven largely by the higher likelihood of having an event in the cohort with an RS 26–100.

Clarity on which patients can be spared chemotherapy

  • No statistically significant difference between treatment groups for freedom from distant recurrence at 9 years2
  • TAILORx showed that patients with Recurrence Score results 11–25 can be spared chemotherapy2

Subset analysis in patients aged 50 or younger

In an exploratory analysis, TAILORx showed a chemotherapy benefit for early breast cancer patients aged 50 or younger with RS scores of 16–25. This subgroup represents about 8% of patients.5

View Subset Analysis
View Subset Analysis

Backed by clinical data

The landmark TAILORx trial is not the only large, randomized clinical trial supporting the use of the Breast Recurrence Score® report.

View more evidence



TAILORx: Transforming the Treatment of Breast Cancer

The TAILORx trial reports 9-year outcomes for >10,000 women with early breast cancer. Over 1,000 trial sites in 6 countries participated.

ASCO = American Society of Clinical Oncology
ECOG-ACRIN = Eastern Cooperative Oncology Group - American College of Radiology and Imaging Network
NIH = National Institutes of Health
NRG = Non-profit Research Group
RS = Recurrence Score
SWOG = Southwest Oncology Group
TAILORx = A Clinical Trial Assigning IndividuaLized Options for Treatment (Rx)

The TAILORx trial was conducted independently by the ECOG-ACRIN Cancer Research Group.


1. Sparano et al. N Engl J Med. 2015.
2. Sparano et al. N Engl J Med. 2018.
3. Sparano et al. ASCO 2018.
4. Paik et al. J Clin Oncol. 2006.
5. Data on file, Genomic Health Inc.


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