Study: Extending aromatase inhibitor duration to 10 years lowers recurrence for ER/PR+ breast cancer patients
Contents
At a glance | In-depth |
Findings | Limitations |
Clinical trials | Guidelines |
Questions for your doctor | Resources |
STUDY AT A GLANCE
This study is about:
Whether patients will benefit (lower risk of recurrence or new breast cancer in the other breast) if they stay on aromatase inhibitor therapy for 10 years rather than the standard 5 years.
Why is this study important?
According to the lead author of this research study, patients with breast cancer live for a long time, but “face an indefinite risk of relapse.”
Study findings:
- When the study ended, 95% of women who had 10 years of aromatase inhibitor therapy (Letrozole) had disease-free survival (meaning they did not develop a recurrence or a new cancer in the other breast), while 91% of women who had 5 years of aromatase inhibitor therapy had disease-free survival at the study endpoint.
- Women who took the aromatase inhibitor for 10 years compared to 5 had no benefit in overall survival.
What does this mean for me?
This data suggests that extending aromatase inhibitor therapy to 10 years instead of stopping it at 5 may improve patient outcomes. Women who were on aromatase inhibitor therapy for 10 years did not have recurrences or develop new cancers in the other breast, although the difference between the 5-year and 10-year groups was relatively low. Women on 10 years of aromatase inhibitors experienced more side effects related to bone density and fractures. Women should have a risk/benefit conversation with their healthcare providers to discuss if extending aromatase inhibitor therapy is right for them. Patients also need to consider the side effects of aromatase inhibitors and the cost of the drug.
Posted 7/26/16
Share your thoughts on this XRAYS article by taking our brief survey.
References
Goss PE, Ingle JN, Pritchard K, et al, “Extending Letrozole for 5 years after completing an initial 5 years of Aromatase Inhibitor therapy alone or preceded by Tamoxifen in Postmenopausal Women with Breast Cancer: A Phase III Open Label Trial.” Presented by Paul Goss at the 2016 American Society of Clinical Oncology Meeting.
Goss PE, Ingle JN, Pritchard K, et al, “Extending Aromatase-Inhibitor Therapy to 10 Years.” The New England Journal of Medicine. Published online first on June 5th, 2016.
Goss, Pe. “Letrozole in the extended setting: MA.17.” Breast Cancer Research and Treatment. 2007;105:45-53.
This article is relevant for:
This article is also relevant for:
people with breast cancer
people with ER/PR + cancer
Be part of XRAY:
IN DEPTH REVIEW OF RESEARCH
Study background:
Researchers of this current study explored whether extending the length of time women took the aromatase inhibitor provided additional benefit. Paul Goss and his colleagues at Massachusetts General Hospital and other institutions presented their data on this new clinical trial (MA.17R) at the 2016 American Society of Clinical Oncology Meeting, Their observations of what happens when women take an aromatase inhibitor for 10 years instead of 5 were also published in The New England Journal of Medicine.
This study follows previous research showing that taking an aromatase inhibitor (Letrozole) after 5 years of tamoxifen improved disease-free survival.
Researchers of this study wanted to know:
Whether patients who stay on an aromatase inhibitor for 10 years have fewer recurrences and develop fewer new breast cancers than patients who take aromatase inhibitors for 5 years.
Population(s) looked at in the study:
The study enrolled 1,918 postmenopausal women who had receptor (ER)- and/or progesterone receptor (PR)-positive, breast cancer.
Women in the study fell into 1 of 3 groups:
- One group had received about 5 years of aromatase inhibitor (AI) therapy (Letrozole) in the researchers’ previous study, and took tamoxifen before AI therapy.
- The second group of women was not included in the previous study, and had received any of the 3 aromatase inhibitors currently in use for about 5 years, and took tamoxifen before AI therapy.
- The third group received about 5 years of any of the 3 current aromatase inhibitors currently in use, but never took tamoxifen.
Among the 3 groups of women, some were to receive another 5 years of AI therapy (Letrozole) or 5 years of receiving a .
Study findings:
- When the study ended, 95% of women who had 10 years of aromatase inhibitor therapy (Letrozole) had disease-free survival (meaning they did not develop a recurrence or a new cancer in the other breast), while 91% of women who had 5 years of aromatase inhibitor therapy had disease-free survival at the study endpoint.
- In total, 67 patients who took Letrozole for 10 years developed a recurrence of cancer in the other breast, compared to 98 patients who took Letrozole for 5 years.
- Women who took an aromatase inhibitor for 10 years had no additional benefit in overall survival compared to those who took an aromatase inhibitor for 5 years.
- Patients who took Letrozole for 10 years were more likely to develop bone fractures than the patients who took it only for 5 years (14% versus 9%).
Limitations:
This research did not take genetic status into account, so how women with mutations in or other genes that increase cancer risk respond to an additional 5 years of aromatase inhibitor therapy is unknown. Some patients involved in the study had previously taken tamoxifen, while some had not. From the data presented, it is not known if the use of tamoxifen before an aromotase inhibitor affected a patient’s risk of recurrence or new cancer. Finally, a number of aromatase inhibitors are available, and not all women in the study took the same aromatase inhibitor for the first 5 years.
Conclusions:
The results of this study suggest that taking an aromatase inhibitor for 10 years instead of 5 may benefit ER- and/or PR-positive breast cancer patients. But there was no increase in overall survival between women who took aromatase inhibitors for 5 years and those who took aromatase inhibitors for 10 years. Patients should discuss with their health care provider all the risks and benefits when thinking about extending their aromatase inhibitor for longer than 5 years.
Posted 7/26/16
Share your thoughts on this XRAYS article by taking our brief survey.
In 2019, the American Society of Clinical Oncology (ASCO) published updated guidelines on endocrine treatment (hormonal therapy) for women with breast cancer. The guidelines recommended:
- Women with node-positive breast cancer should receive extended therapy, including an aromatase inhibitor, for up to a total of 10 years of endocrine treatment.
- Women with node-negative breast cancer should consider extended therapy for up to a total of 10 years of endocrine treatment based on considerations of their risk for recurrence.
- The decision to extend or not extend hormone therapy should be a shared decision between doctors and patients based on discussions that weighs the benefits of lowering the risk for breast cancer recurrence and preventing second breast cancers versus the negative impact of treatment side effects.
The ASCO Panel notes that the benefits of reduction are small and that a substantial portion of the benefit for extended aromatase inhibitor therapy comes from preventing a new breast cancer diagnosis.
Updated: 01/02/2022
- Should I extend aromatase inhibitor therapy to 10 years?
- What other ways can help me to prevent or lower my risk of breast cancer recurrence?
- I have taken tamoxifen for 5 years; should I consider changing to an aromatase inhibitor?
- What are the side effects and of hormonal therapies like tamoxifen?
- What are the side effects and of aromatase inhibitors?
- What are the added side effects of extending hormonal therapy beyond 5 years?
- I have been on an aromatase inhibitor and my bone density has gone down. Is there anything I can do to improve my bone density?
The following are studies enrolling people with early ER-positive, breast cancer.
- NCT03053193: MammaPrint, BluePrint, and Full-genome Data Linked With Clinical Data to Evaluate New Gene EXpression Profiles (FLEX). The FLEX Registry is a large-scale, population based, registry. All patients with I to III breast cancer who receive MammaPrint® and BluePrint testing on a primary breast tumor are eligible for entry into the FLEX Registry.
- NCT05607004: (Z)-Endoxifen for the Treatment of Premenopausal Women With ER+/HER2- Breast Cancer (EVANGELINE). This study is looking at drug called (Z)-endoxifen as a possible treatment for pre-menopausal women with ER+/HER2- breast cancer. (Z)-endoxifen is a type of hormone therapy that blocks the body's natural from binding to cancer cells.
- NCT04584255: Treating HER2-Negative Breast Cancer with a () and (Dostarlimab) in People with a or Mutation. This study will look at how well the drugs (a ) and Dostarlimab (an ) treat breast cancer in people with an inherited , or mutation.
- NCT03749421: Prosigna Assay on Clinical Decision-making in Women With HR+/Her2- Breast Cancer. This research study is evaluating a genomic analysis called Predictor Analysis of Microarray 50 (PAM50, by Prosigna®) as a tool to possibly guide the participant and the treating physician to choose the most personalized pre-operative treatment for breast cancer.
- NCT04567420: DNA-Guided Second Line Therapy For High Residual Risk, II-III, Hormone Receptor Positive, Negative Breast Cancer. This study will monitor people with , high-risk breast cancer for possible recurrence using a test called circulating tumor (). People who test positive for but who have no other signs of recurrence, will receive either the drugs palbociclib combined with fulvestrant or standard-of-care hormone therapy.
-
NCT04852887: De-Escalation of Breast Radiation Trial for Hormone Sensitive, HER-2 Negative, Oncotype Recurrence Score Less Than or Equal to 18 Breast Cancer (DEBRA). This study evaluates whether breast conservation surgery and endocrine therapy results in a non-inferior rate of invasive or non-invasive ipsilateral breast tumor recurrence (IBTR) compared to breast conservation with breast radiation and endocrine therapy.
A number of other clinical trials for patients with breast cancer can be found here.
Updated: 02/01/2024
The following organizations offer peer support services for people with, or at high risk for breast cancer:
- FORCE peer support:
- Our Message Boards allow people to connect with others who share their situation. Once you register, you can post on the Diagnosed With Cancer board to connect with other people who have been diagnosed.
- Our Peer Navigation Program will match you with a volunteer who shares your mutation and situation.
- Connect online with our Private Facebook Group.
- Join our virtual and in-person support meetings.
- Other organizations that offer breast cancer support:
Updated: 05/07/2024
Who covered this study?
Clinical Oncology News
What Is the benefit of extending AIs beyond five years? This article rates 4.5 out of 5 stars
Washington Post
Extending anti-estrogen therapy to 10 years reduces breast-cancer recurrence, new cancers This article rates 4.5 out of 5 stars
The Guardian
Breast cancer drugs should be given for 10 years, study shows This article rates 3.0 out of 5 stars