TAILORx Finds Some Women With Hormone Receptor-Positive Breast Cancer Can Skip Chemotherapy

The trial shows surgery and hormonal therapy is enough for many women with mid-range Oncotype DX scores
Breast Cancer News
July 30, 2018
By: 
Eric Fitzsimmons, Copy Editor and Content Coordinator
Reviewed By: 
Pallav K. Mehta, MD

Most postmenopausalinfo-icon women with hormone receptorinfo-icon-positive, HER2-negative, node-negativeinfo-icon breast cancer and Oncotype DX scores below 25 can be treated with hormonal therapyinfo-icon alone after surgeryinfo-icon, according to TAILORx trial results published in the New England Journal of Medicineinfo-icon in June. The findings mean that for this specific group of women, chemotherapyinfo-icon and its side effects can be safely avoided while still effectively treating the cancer.

They also provide more information for women under age 50 with scores between 11 and 25, many of whom will still need chemotherapy treatment.

Background

Chemotherapy has long been recommended for many people with breast cancer to lower the risk of recurrenceinfo-icon. But past research seemed to suggest that some people, particularly those with hormone receptor-positive disease, may not need it. The problem was that doctors had few tools to identify who absolutely needed chemotherapy for successful treatment, and who did not.

Oncotype DX is a genomic assayinfo-icon, a test that looks at certain features of the DNA in the breast cancer tumorinfo-icon and predicts how likely the cancer is to come back after treatment. A piece of the tumor is tested and given a Recurrence Score, a number from 1 to 100.  Higher scores mean a higher risk of the cancer returning, and lower scores mean a lower risk of the cancer returning. Right now, the test is only available to people who have hormone receptor-positive, HER2-negative disease, although some clinicalinfo-icon trials are looking at its use in other subtypes.

Past research found breast cancers that score 10 or under have a very low risk of returning and that chemotherapy is not likely to lower that risk. But breast cancers that score above 30 have a higher risk of returning, and that risk may be lessened by adding chemotherapy to treatment.

While this meant clear guidance for people with a very low or very high risk of recurrence, many people who get the Oncotype DX test score somewhere between 10 and 30, and doctors had no certain measure of whether chemotherapy would be helpful for them or not.

TAILORx looked at those in this middle range of scores to see if certain people within it would clearly need chemotherapy to lower their risk of recurrence.

Design

TAILORx was designed to give more people a clear answer on whether they need chemotherapy to best avoid cancer coming back. The study included 9,719 women who

  • had hormone receptor-positive, HER2-negative, early-stage breast cancerinfo-icon
  • had no cancer in the lymphinfo-icon nodes
  • met clinical guidelines to have chemotherapy considered or recommended

As part of the study, the women were given the Oncotype DX test and agreed to have their treatment based on the score of that test. Women with a Recurrence Score between 11 and 25 were randomly assigned to get either

  • hormonal therapy alone, or
  • chemotherapy followed by hormonal therapy

Women with a Recurrence Score of 10 or below were assigned

  • hormonal therapy alone

Women with scored Recurrence Score above 25 were assigned

  • chemotherapy followed by hormonal therapy

The largest trial group — 6,711 women — had scores between 11 and 25. The goal of the researchers was to see if hormonal therapy alone could do as well as hormonal therapy and chemotherapy at stopping breast cancer from returning.

Results

TAILORx found that hormonal therapy alone was enough treatment for women with a Recurrence Score of 25 or lower.

After 9 years of follow-up,  there was little difference in outcomes for the women with a score of 11-25, regardless of the treatment they received:

  • 83.3 percent of the group given only hormonal therapy were alive and cancer free
  • 84.3 percent of the group given both chemotherapy and hormonal therapy were alive and cancer free

The results were also similar in the secondary endpoints (goals) of the trial, which included:

  • how many women lived without breast cancer returning to other parts of the body
  • how many women lived without breast cancer returning to the breast or chest
  • overall survival, the time from start of participation in the study to death from any cause

When the researchers looked at the results of the 11 to 25 score group by age, one group had a lower chance of cancer returning when treated with chemotherapy: women under age 50. The younger women had low rates of cancer returning if they had tumors that scored 15 or lower. But starting at scores of 16, chemotherapy lowered the risk of breast cancer returning. How much chemotherapy lowered the risk of recurrence was larger for higher scores.

What This Means for You

The TAILORx results are expected to lead to fewer women getting chemotherapy for early-stage breast cancer. About half of all breast cancer cases in the U.S. are hormone receptor-positive and have not traveled to the axillary lymph nodes, according to the researchers. The recommendations are expected to go into practice quickly.

If you have recently been diagnosed with hormone receptor-positive, HER2-negtive, node-negative breast cancer, the Oncotype DX test will likely be a part of your treatment decisions. It is OK to ask your doctor why they do or do not recommend certain treatments or tests. Even if your Recurrence Score suggests you don’t need chemotherapy, other features of the cancer may lead your doctor to recommend it. If you do not feel your questions were clearly answered, consider getting a second opinion.

If you already had chemotherapy but fit into these categories, know that your doctors made the best decision they could with the information they had at the time. As our knowledge of cancer and treatments move forward, doctors will better understand who benefits from certain medicines and who does not.

If are under the age of 50, you may still have chemotherapy recommended even if the cancer has a Recurrence Score as low as 20. Researchers were not sure why this is, but they suggested it may be because chemotherapy stops the function of your ovaries. This will encourage ongoing research into treatments that combine ovarianinfo-icon function suppression with hormonal therapy.

Sparano, JA; Gray, RJ; Makower, DF; et al. Adjuvant Chemotherapy Guided by a 21-Gene Expression Assay in Breast CancerNew England Journal of Medicine. June 2018; DOI: 10.1056/NEJMoa1804710

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