What side effects are associated with this type of intervention?

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, may lead to loss of bone density, increased risk of fractures, and cardiovascular issues. These therapies are essential for managing hormone receptor-positive breast cancer by inhibiting estrogen receptor signaling.

What prior FDA approvals exist?

The FDA has approved several endocrine therapies for the treatment of hormone receptor-positive breast cancer. These include tamoxifen, a selective estrogen receptor modulator, and aromatase inhibitors such as letrozole and anastrozole, which reduce estrogen production. These drugs are used to inhibit estrogen receptor signaling, thereby slowing the growth of hormone receptor-positive tumors in various stages of breast cancer, including early-stage, metastatic, and recurrent cases.

What other types of research exist?

Promising novel alternatives to endocrine therapy for breast cancer patients include: 1) CDK4/6 inhibitors (e.g., palbociclib, ribociclib) which target cell cycle regulation, 2) PI3K inhibitors (e.g., alpelisib) for patients with PIK3CA mutations, 3) mTOR inhibitors (e.g., everolimus) in combination with other therapies, and 4) immune checkpoint inhibitors (e.g., pembrolizumab) for certain subtypes of breast cancer. These therapies have shown efficacy in clinical trials and offer new avenues for treatment beyond traditional endocrine therapy.

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Hormone Therapy

Endocrine Therapy Before Surgery for Early-Stage Breast Cancer (POWER Trial)

Phase 2

Waitlist Available

Led By Shayna L Showalter, MD

Research Sponsored by Trish Millard, MD

Eligibility Criteria Checklist

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

Must have

Ability to take oral medication and be willing to adhere to the endocrine therapy for the 3 month period prior to BCS

ECOG performance status 0-2

Must not have

Prior or current use of endocrine therapy for breast cancer

History of ipsilateral breast radiation

Timeline

Screening 3 weeks

Treatment Varies

Follow Up up to 90 days after surgery, chemotherapy completion, or rt completion, whichever is later

Awards & highlights

No Placebo-Only Group

Summary

This trial is testing if giving hormone therapy helps older women with early-stage breast cancer tolerate the treatment and decide if they can skip radiation. The therapy works by blocking estrogen, which some breast cancers need to grow.

Who is the study for?

This trial is for women aged 65 or older with early-stage, hormone receptor-positive breast cancer. Participants must have a tumor size ≤ 2 cm, be able to take oral medication, and commit to pre-surgery endocrine therapy for three months. They should not have used endocrine therapy before, be pregnant or breastfeeding, or require treatment for another progressing malignancy.

What is being tested?

The study tests the tolerance of older women with breast cancer to pre-operative endocrine therapies like tamoxifen, letrozole, anastrozole, or exemestane over three months. Patient surveys will measure how well they tolerate the drugs before surgery.

What are the potential side effects?

Possible side effects from these medications can include hot flashes, mood swings, fatigue, joint pain and bone thinning (osteoporosis). Each woman's experience may vary based on her health and reaction to the medication.

Eligibility Criteria

Inclusion Criteria

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

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I can take pills and will follow hormone therapy for 3 months before surgery.

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I can take care of myself and perform daily activities.

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I have chosen breast-conserving surgery.

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My tumor is 2 cm or smaller.

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I can take tamoxifen or an aromatase inhibitor.

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I have early-stage breast cancer that is ER positive and may or may not be PR positive, but is not HER2 positive.

Exclusion Criteria

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

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I have used hormone therapy for breast cancer.

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I have had radiation therapy on the same side of my breast before.

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I am using or will use a strong medication that affects liver enzyme CYP2D6 and cannot switch to another that doesn't.

Timeline

Screening ~ 3 weeks3 visits

Treatment ~ Varies

Follow Up ~ up to 90 days after surgery, chemotherapy completion, or rt completion, whichever is later

Screening ~ 3 weeks

Treatment ~ Varies

Follow Up ~up to 90 days after surgery, chemotherapy completion, or rt completion, whichever is later

This trial's timeline: 3 weeks for screening, Varies for treatment, and up to 90 days after surgery, chemotherapy completion, or rt completion, whichever is later for reporting.

Treatment Details

Study Objectives

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

Primary study objectives

Change in participant preference for adjuvant radiation treatment

Change in surgeon preference for adjuvant radiation treatment

Secondary study objectives

Beliefs about medicine as predictive measure for endocrine therapy adherence and to assess effect of pre-ET on decision outcomes for adjuvant therapy after BCS

Breast cancer beliefs as predictive measure for endocrine therapy adherence and to assess effect of pre-ET on decision outcomes for adjuvant therapy after BCS

Depression and anxiety as predictive measure for endocrine therapy adherence

+6 more

Awards & Highlights

No Placebo-Only Group

All patients enrolled in this study will receive some form of active treatment.

Trial Design

1Treatment groups

Experimental Treatment

Group I: Pre-operative endocrine therapyExperimental Treatment2 Interventions

All participants enrolled to the study will receive 3 months of pre-operative endocrine therapy (e.g. tamoxifen or aromatase inhibitors (AIs) such as letrozole, anastrozole, or exemestane). The choice and dose of endocrine therapy will be at the discretion of the treating medical oncologist.

Treatment

First Studied

Drug Approval Stage

How many patients have taken this drug

Patient reported outcomes

2019

N/A

~100

0 / 9Eligibility 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 for breast cancer, such as selective estrogen receptor modulators (SERMs) like tamoxifen and aromatase inhibitors like letrozole and anastrozole, work by inhibiting estrogen receptor signaling. Tamoxifen blocks estrogen receptors on cancer cells, while aromatase inhibitors reduce estrogen production in the body. These treatments are particularly effective for hormone receptor-positive breast cancers. Additionally, targeted therapies like gefitinib are being explored to overcome resistance to treatments like tamoxifen. Understanding these mechanisms is vital for breast cancer patients as it aids in selecting the most effective treatment based on the tumor's hormone receptor status, potentially improving outcomes and reducing the risk of recurrence.

A review of an unfavorable subset of breast cancer: estrogen receptor positive progesterone receptor negative.Endocrine and targeted manipulation of breast cancer: summary statement for the Sixth Cambridge Conference.