Exercise Program Study for Early Breast Cancer Patients Taking Aromatase Inhibitors With or Without CDK4/6 Inhibitors to Improve Quality of Life

3 1 1 1

What is this study about?

This study involves patients with early breast cancer who are receiving specific hormone treatments. The disease being studied is hormone receptor positive and HER2 negative breast cancer that has been treated and shows no signs of remaining disease. The treatments used in this study include several types of hormone-blocking medications. These include anastrozole, which is given as a tablet by mouth, letrozole, also taken as a tablet, and exemestane, another tablet form medication. Some patients may also receive medications that suppress hormone production, such as goserelin, which is given as an implant injection into the muscle, or leuprorelin acetate, which is given as an injection that releases medication slowly over time. Additionally, some patients may be taking medications called CDK4/6 inhibitors, which include abemaciclib or ribociclib, both given as tablets. These CDK4/6 inhibitors help prevent cancer cells from growing and dividing.

The purpose of this study is to find out if a six-month exercise training program can improve the quality of life for patients who are taking these hormone treatments. Hormone treatments can cause various side effects that affect daily life, and exercise may help reduce these effects. The study will look at how exercise impacts symptoms related to the hormone treatment, overall quality of life, joint and muscle pain, tiredness, body composition including weight and muscle mass, sexual health, thinking abilities, and how well patients are able to continue taking their prescribed medications.

Patients who join the study will be randomly assigned to either participate in a supervised exercise program for six months or to continue with their usual activities. Those in the exercise group will work with exercise professionals and use a virtual training platform to help them follow the program. Throughout the study, all patients will continue taking their regular breast cancer medications as prescribed by their doctors. Patients will be asked to complete questionnaires at different times during the study to assess their quality of life, pain levels, and fatigue. They will also have measurements taken of their body composition and will have regular medical check-ups to monitor their health and any side effects from their cancer treatment. The study will track how well patients stick to both their exercise program and their cancer medications.

1 Starting treatment and baseline assessment

At the time of joining this trial, your treatment with hormone therapy will already be underway. You will have been taking an aromatase inhibitor medication (a type of hormone therapy that reduces estrogen in your body) for 10 to 18 weeks.

If applicable, you may also be receiving a luteinizing hormone-releasing hormone agonist, which is a medication that stops your ovaries from producing hormones. This is given as an injection into the muscle.

Some patients may also be taking a CDK4/6 inhibitor medication (which helps prevent cancer cells from growing). If this applies to you, you will have been taking it for at least 6 weeks before joining the trial.

At this starting point, you will complete questionnaires about your quality of life, any pain you may be experiencing, and how tired you feel.

Your body composition will be measured using a special scale that assesses your weight, body mass index, muscle mass, fat mass, water percentage, bone density, and metabolic rate.

2 Randomization into treatment groups

You will be assigned to one of two groups. This assignment will be done randomly, meaning neither you nor your doctor can choose which group you will be in.

One group will participate in a supervised exercise program in addition to continuing hormone therapy. The other group will continue with hormone therapy alone without the structured exercise program.

Regardless of which group you are assigned to, you will continue taking your prescribed hormone therapy medications as directed by your doctor.

3 Continuing hormone therapy medications

You will continue taking your aromatase inhibitor medication daily by mouth. The specific medication may be anastrozole (1 mg tablet), letrozole (2.5 mg tablet), or exemestane (25 mg tablet), depending on what your doctor has prescribed.

If you are receiving hormone injections, these will continue according to your treatment plan. Goserelin may be given as an implant (either 3.6 mg or 10.8 mg), or you may receive leuprorelin acetate injections into the muscle (either 3.75 mg monthly or 22.5 mg every three months).

If you are taking a CDK4/6 inhibitor, you will continue with either ribociclib (200 mg tablets) or abemaciclib (available as 50 mg, 100 mg, or 150 mg tablets) by mouth, according to your prescribed schedule.

Your adherence to these medications will be monitored through pill counting and a patient diary that you will be asked to maintain.

4 Six-month intervention period

This phase will last for 6 months.

If you are in the exercise group, you will participate in a structured physical activity program supervised by exercise professionals. Your participation in the exercise sessions will be tracked through a virtual training platform.

If you are in the other group, you will continue with your regular activities and hormone therapy without the structured exercise program.

Throughout these 6 months, you will attend scheduled visits and complete questionnaires at specific time points to assess your quality of life, pain levels, fatigue, and other aspects of your well-being.

Your body composition will be measured again using the bioimpedance scale at designated times during this period.

Standard blood tests will be performed to monitor your health and check for any side effects from the medications.

5 Ongoing assessments during the trial

You will complete questionnaires about symptoms related to your hormone therapy, including questions about sexual health, body image, cognitive function, and overall quality of life.

Any side effects or health changes you experience will be recorded and assessed according to standard medical criteria.

Your doctor will monitor how well you are tolerating the medications, including any need for dose adjustments or changes to your treatment plan.

Information about your treatment adherence will be collected through your patient diary and pill counts at visits.

6 End of the six-month period

At the completion of the 6-month period, you will undergo final assessments including questionnaires and body composition measurements.

The information collected will be used to evaluate the impact of the exercise program on quality of life for patients receiving hormone therapy.

Your participation in the trial procedures will be complete at this point, though you will continue with your prescribed cancer treatment as recommended by your doctor.

Who Can Join the Study?

  • You must sign a written informed consent document before any study procedures begin, showing that you are willing and able to follow the physical activity program if assigned to that group, and attend all scheduled visits and complete study procedures.
  • Your doctor must agree that it is safe for you to participate in physical training based on your medical history.
  • You must be at least 18 years old when you sign the consent document.
  • You must have early breast cancer that was confirmed by examining tissue under a microscope, showing it is hormone receptor positive (meaning the cancer grows in response to hormones) and HER2 negative (meaning the cancer does not have too much of a certain protein called HER2). Your cancer must have been properly treated and there must be no signs of cancer remaining in your body or spreading to other areas.
  • Your overall health and ability to carry out daily activities must be rated as good to moderate on a scale called ECOG performance status, with a score between 0 and 2, where 0 means fully active and 2 means able to care for yourself but unable to work.
  • You must be a woman of any menopausal status (before, during, or after menopause) and already taking a medication called an aromatase inhibitor (a hormone therapy that lowers estrogen levels) for 10 to 18 weeks before joining the study. If you also need a medication called a CDK4/6 inhibitor, you must have started it at least 6 weeks before joining the study.
  • You must have completed appropriate local treatment for your breast cancer, which includes surgery with or without radiation therapy (treatment using high-energy rays to kill cancer cells), and you may or may not have received chemotherapy (medications to kill cancer cells) before or after surgery.
  • Your organs and bone marrow (the soft tissue inside bones that makes blood cells) must be functioning adequately according to standard medical practice.
  • You must be able and willing to complete repeated questionnaires about your quality of life, pain, and tiredness, and follow the physical activity program.
  • You must speak Spanish fluently to fully understand the questionnaires.

Who Cannot Join the Study?

  • You cannot participate if you are male. This study is only for female patients.
  • You cannot participate if you are outside the specified age range for this study.
  • You cannot participate if you do not have early breast cancer, which means breast cancer that has been found at an early stage and has not spread widely in the body.
  • You cannot participate if you are not receiving ET, which stands for endocrine therapy. This is a treatment that uses medications to block hormones that help cancer cells grow.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name City Country Status
Hospital Universitario De Navarra Pamplona Spain
Hospital Clinico San Carlos Madrid Spain

Other Sites

Site Name City Country Status
Hospital Quironsalud Sagrado Corazon Sevilla Spain
Izlcuual Cpqwnb Djcnjvhhgsfycilij L'hospitalet De Llobregat Spain

Want to learn more about this study or check if you can participate? Contact us.

Trial status

Country Status Recruitment Start
Spain Spain
Not yet recruiting
02.02.2026

Trial locations

Aromatase Inhibitors are medications used to treat breast cancer. They work by blocking an enzyme called aromatase, which helps produce estrogen in the body. Since some breast cancers need estrogen to grow, these medications help slow or stop the cancer by reducing estrogen levels.

CDK4/6 inhibitors are medications that help treat breast cancer by blocking proteins called CDK4 and CDK6. These proteins help cancer cells grow and divide. By blocking them, these medications can slow down or stop the growth of cancer cells.

Early Breast Cancer – Early breast cancer refers to cancer that is confined to the breast or has only spread to nearby lymph nodes under the arm, but has not spread to other parts of the body. The disease begins when cells in the breast tissue start to grow abnormally and form a lump or mass. These abnormal cells can multiply and invade surrounding breast tissue over time. In early stages, the cancer is still localized and has not reached distant organs. The condition may progress from a small tumor confined to the breast tissue to involvement of nearby lymph nodes. Without intervention, early breast cancer can advance to more extensive disease affecting larger areas of the breast and surrounding tissues.

Trial ID:
2025-522848-40-00
Protocol code:
GEICAM/2023-09
Trial Phase:
Therapeutic confirmatory (Phase III)

Other Trials to Consider

  • Study Comparing Sacituzumab Govitecan with Other Treatments for Patients with HR+/HER2- Metastatic Breast Cancer After Endocrine Therapy

    Not recruiting

    3 1 1 1
    Austria Belgium Czechia France Germany Greece +5
  • Study on the Impact of Fluoroestradiol F-18 PET on Treatment for Patients with ER+ HER2- Metastatic Breast Cancer After First-Line Hormone Therapy Relapse

    Not recruiting

    3 1 1 1
    Investigated drugs:
    France