Black women diagnosed with early-stage, hormone-receptor-positive, HER2-negative breast cancer had higher rates of recurrence (the cancer coming back) and worse survival compared to white women with the same diagnosis, even though all the women received similar treatment, according to new analysis of TAILORx study information.
The research was presented on Dec. 6, 2018, at the San Antonio Breast Cancer Symposium. Read the abstract of “Race, ethnicity and clinical outcomes in hormone receptor-positive, HER2-negative, node-negative breast cancer: results from the TAILORx trial.”
The results echo earlier research suggesting that breast cancer diagnosed in black women is biologically different than breast cancer diagnosed in white women. Still, this idea hasn’t been well studied because black women traditionally make up a very small percentage of participants in clinical trials. In this study, only 7% of the women were black. So while the results are upsetting, it’s hard to know how widely applicable they are. This also highlights the importance of more black women participating in clinical trials so researchers can figure out the biology of breast cancer in women of different races.
The TAILORx trial
The TAILORx (Trial Assigning IndividuaLized Options for Treatment) trial was designed to figure out which women, if any, diagnosed with early-stage, hormone-receptor-positive, HER2-negative breast cancer with no cancer in the lymph nodes (node-negative), could safely skip chemotherapy after surgery, based on the Oncotype DX Recurrence Score.
The Oncotype DX test is a genomic test that analyzes the activity of a group of 21 genes from a breast cancer tissue sample that can affect how a cancer is likely to behave and respond to treatment.
Doctors use the Oncotype DX test to help figure out a person’s risk of recurrence for early-stage, estrogen-receptor-positive, HER2-negative breast cancer, as well as how likely a person is to benefit from chemotherapy after breast cancer surgery.
The Oncotype DX test results assign a Recurrence Score — a number between 0 and 100 — to the breast cancer. People and their doctors use the following ranges to interpret the Recurrence Score:
- Recurrence Score lower than 18: The cancer has a low risk of recurrence. The benefit of chemotherapy is likely to be small and will not outweigh the risks of side effects.
- Recurrence Score of 18 to 30: The cancer has an intermediate risk of recurrence. It’s unclear whether the benefits of chemotherapy outweigh the risks of side effects.
- Recurrence Score of 31 or higher: The cancer has a high risk of recurrence, and the benefits of chemotherapy are likely to be greater than the risks of side effects.
Results from TAILORx published in 2015 showed that women with a Recurrence Score of 10 or lower could safely skip chemotherapy.
TAILORx results published in June 2018 found that most women with a Recurrence Score of 11 to 25 also could safely skip chemotherapy.
The TAILORx study included 10,273 women diagnosed with hormone-receptor-positive, HER2-negative breast cancer that had not spread to the lymph nodes. The researchers performed Oncotype DX tests on tissue samples from all the cancers, and all the women were then assigned an Oncotype DX Recurrence Score.
- Women with a Recurrence Score of 0 to 10 were treated with hormonal therapy alone after surgery.
- Women with a Recurrence Score of 26 and higher were treated with hormonal therapy and chemotherapy after surgery.
- Women with a Recurrence Score of 11 to 25 were randomly assigned to receive either hormonal therapy alone or hormonal therapy and chemotherapy after surgery.
Comparing outcomes by race, ethnicity
Information from 9,719 women was studied for this analysis:
- 8,189 (84%) were white
- 693 (7%) were black
- 405 (4%) were Asian
- 432 (4%) were other or unknown race
- 7,635 (79%) were non-Hispanic
- 889 (9%) were Hispanic
- 1,195 (12%) were of unknown ethnicity
There were no differences in Recurrence Score averages or Recurrence Score range between black and white women.
Similar numbers of black and white women, as well as similar numbers of Hispanic and non-Hispanic women, were treated with chemotherapy. The type of chemotherapy used also was similar for all these groups of women.
Similar numbers of black and white women, as well as similar numbers of Hispanic and non-Hispanic women, were treated with hormonal therapy. The type of hormonal therapy and the length of time the women took hormonal therapy also were similar for all these groups of women.
At 9 years of follow-up, researchers compared breast cancer outcomes between the racial and ethnic groups. Compared to white women, black women had:
- a 39% higher risk of breast cancer recurrence
- a 52% higher risk of dying from breast cancer
Overall, 68% of the black women in the study had a Recurrence Score of 11 to 25, considered an intermediate score. Compared to white women in this group, black women had:
- an 80% higher risk of breast cancer recurrence
- a 67% higher risk of dying from breast cancer
Hispanic women generally had better outcomes than non-Hispanic women.
"The study adds to an emerging body of evidence suggesting there are biological factors contributing to racial disparities in breast cancer outcomes," said Kathy Albain, M.D., FACP, FASCO, Huizenga Family Endowed Chair in Oncology Research and professor of medicine at Loyola University Chicago Stritch School of Medicine and director of the Breast and Thoracic Oncology Programs at the Cardinal Bernardin Cancer Center of Loyola Medicine, who presented the research. "The racial disparities observed in this trial were not explained by differences in Recurrence Score, duration, or reported adherence to hormone therapy, nor were they explained by use of chemotherapy, or characteristics such as age, tumor size, or tumor grade. This suggests that additional research is required to determine the basis for these racial disparities and also highlights the need to enhance accrual of minority populations in cancer clinical trials."
What this means for you
All people — no matter their race, ethnicity, age, economic status, or other health conditions — deserve the best breast cancer care possible.
Because so many treatment factors were similar between black and white women in this study, the results strongly suggest that there are biological factors about cancer in black women that contribute to worse outcomes.
Still, it's important to remember that only 7% of women in the study were black. As Albain suggested, enrolling more black women in breast cancer studies likely will help researchers find answers to questions about these biological factors.
Researchers don't know what the results of clinical trials will be. (If they did, they wouldn't have to do the trials.) This uncertainty can make it hard to decide if you want to participate in clinical trial. In rare cases, clinical trial volunteers have been hurt by the treatment or procedure being tested. At the same time, hundreds of thousands of people have been helped and are alive because other people chose to participate in a trial that resulted in a new, more effective treatment. While clinical trials are important, the choice to participate in one is very personal and depends on your unique situation. As with any breast cancer treatment, you and your doctor need to weigh the benefits against the risks and decide what's best for you.
As you're considering your choices, it can be helpful to ask the doctors doing the trial the following questions:
- Why are you doing this trial?
- Why do you think this new treatment will be effective?
- What phase is this trial?
- Has this treatment been tested before?
- What were the results of any previous trials?
- Can I talk to someone who's already in the trial?
- Who is paying for the trial?
- What are the possible treatments I can get? How often are they given?
- What types of tests will I have to have, and how often will I have to have them?
- How will being part of this study affect my daily routine?
- What side effects am I likely to have?
- Will my treatment be free? Will my insurance cover any of the cost? Exactly what will I have to pay for?
- How long will the trial last?
- Is long-term follow-up care part of the trial? What does it involve?
- If the treatment works for me, can I continue to get it after the trial is done?
- How do I get the results of the trial?
For more information, visit the Breastcancer.org Clinical Trials pages.
To discuss clinical trial experiences and results with others, join the Breastcancer.org Discussion Board forum Clinical Trials, Research News, Podcasts, and Study Results.
Editor’s Note: This article was updated on Jan. 22, 2019, with some clarifications.
Written by: Jamie DePolo, senior editor
Reviewed by: Brian Wojciechowski, M.D., medical adviser