What side effects are associated with this type of intervention?

The most common treatments for breast cancer, particularly endocrine therapies like tamoxifen and aromatase inhibitors, have several known side effects. Tamoxifen can cause hot flashes, vaginal dryness or discharge, and an increased risk of blood clots and endometrial cancer. Aromatase inhibitors, such as anastrozole, are associated with bone density loss, increased risk of fractures, and cardiovascular issues. Both treatments can also lead to joint pain and fatigue. These side effects are important considerations, especially in older patients with lower-risk breast cancer, where the balance between treatment benefits and quality of life is crucial.

What prior FDA approvals exist?

The FDA has approved several endocrine therapies for the treatment of breast cancer, particularly for hormone receptor-positive (HR+) types. Tamoxifen, a selective estrogen receptor modulator, was one of the first to be approved and is commonly used in both premenopausal and postmenopausal women. Aromatase inhibitors such as anastrozole, letrozole, and exemestane are also approved for postmenopausal women and work by reducing estrogen levels in the body. These therapies are often used as adjuvant treatments to reduce the risk of recurrence. The trial on the omission of endocrine therapy in older patients with lower-risk breast cancer is evaluating the impact of not using these standard treatments to understand their necessity in this specific patient group.

What other types of research exist?

Promising alternatives to the omission of endocrine therapy for older patients with lower-risk breast cancer include the use of lower-dose tamoxifen (10 mg every other day) and aromatase inhibitors like anastrozole. Lower-dose tamoxifen has shown a similar relative risk reduction in recurrence with fewer severe toxicities compared to the standard dose. Anastrozole is a reasonable alternative for postmenopausal women, though it comes with risks such as bone density loss and cardiovascular issues. These alternatives aim to balance efficacy in reducing recurrence rates with a better side effect profile, making them suitable for older patients.

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Hormone Therapy

Endocrine Therapy for Older Patients with Breast Cancer

Phase 4

Waitlist Available

Led By Marie-France Savard, MD

Research Sponsored by Ottawa Hospital Research Institute

Eligibility Criteria Checklist

Specific guidelines that determine who can or cannot participate in a clinical trial

Must have

The primary tumour characteristics are either: Grade 1 and ≤5 cm on microscope exam, OR Grade 2 and ≤3 cm on microscope exam, OR Grade 3 and ≤1 cm on microscope exam

New invasive estrogen and/or progesterone receptor-positive (ER+ and/or PR+), HER2-negative (HER2-) invasive breast carcinoma diagnosis as per ASCO-CAP guidelines

Must not have

Metastatic cancer

Timeline

Screening 3 weeks

Treatment Varies

Follow Up 4 weeks after study enrolment

Awards & highlights

Summary

This trial is testing if older women (70+) with low-risk early breast cancer can safely skip hormone-blocking treatment. The goal is to see if they can avoid the side effects of this treatment without increasing the risk of cancer returning.

Who is the study for?

This trial is for patients aged 70 or older with early-stage, lower-risk hormone receptor-positive breast cancer. They must be able to consent and fill out questionnaires in French or English, have a new diagnosis of certain types of breast carcinoma, and have undergone specific surgeries without metastatic cancer.

What is being tested?

The study is testing the necessity of endocrine therapy (ET) after surgery in older patients with low-risk breast cancer. It randomly assigns participants to either receive ET or no ET post-surgery to see if omitting ET can still effectively manage their condition.

What are the potential side effects?

Endocrine therapy may cause hot flashes, fatigue, mood swings, reduced sex drive, bone thinning (osteoporosis), joint pain, and an increased risk of blood clots.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below

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My tumor is small and varies in aggressiveness based on its size.

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My breast cancer is ER+ and/or PR+, and HER2-.

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I had surgery to remove my breast cancer and then received radiation.

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My cancer has not spread to the lymph nodes under my arm.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:

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My cancer has spread to other parts of my body.

Timeline

Screening ~ 3 weeks3 visits

Treatment ~ Varies

Follow Up ~ 4 weeks after study enrolment

Screening ~ 3 weeks

Treatment ~ Varies

Follow Up ~4 weeks after study enrolment

This trial's timeline: 3 weeks for screening, Varies for treatment, and 4 weeks after study enrolment for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.

Primary study objectives

90% treatment allocation rate

Accrual of 100 participants across 8 centres within 2 years

Participation rate of at least 60%

Secondary study objectives

Endocrine therapy related toxicity

Health-related quality of life scores

Rate of treatment discontinuation

+1 more

Trial Design

2Treatment groups

Experimental Treatment

Active Control

Group I: Omission of endocrine therapyExperimental Treatment1 Intervention

Omission of endocrine therapy

Group II: Administration of endocrine therapy for at least 5 yearsActive Control1 Intervention

Administration of endocrine therapy for at least 5 years

0 / 5Eligibility criteria met

Research Highlights

Information in this section is not a recommendation. We encourage patients to speak with their healthcare team when evaluating any treatment decision.

Mechanism Of Action

Side Effect Profile

Prior Approvals

Other Research

Endocrine therapies, such as tamoxifen and aromatase inhibitors (e.g., anastrozole), are commonly used to treat hormone receptor-positive breast cancer. Tamoxifen works by blocking estrogen receptors on breast cancer cells, preventing estrogen from binding and stimulating cancer growth. Aromatase inhibitors reduce the production of estrogen in postmenopausal women by inhibiting the enzyme aromatase, which converts androgens to estrogen. These treatments are crucial for reducing the risk of cancer recurrence and improving survival rates in patients with hormone receptor-positive breast cancer. Understanding their mechanisms helps in tailoring treatment plans, especially for older patients with lower-risk profiles, where the balance between benefits and potential side effects must be carefully considered.

Extended Adjuvant Endocrine Therapy in Breast Cancer: Evidence and Update - A Review.Implementing neoadjuvant endocrine strategies in ER-positive, HER2-negative breast cancer.Extending the clinical benefit of endocrine therapy for women with hormone receptor-positive metastatic breast cancer: differentiating mechanisms of action.