Study: Moderate exercise delays time to breast cancer recurrence

Relevance: Medium-High

Strength of Science: Medium-High

Research Timeline: Post Approval

Relevance Rating Details

What is this study about?

This study looks at the impact of exercise on the risk of distant recurrence (metastasis) in premenopausal and postmenopausal women with different types of early-stage breast cancer. Researchers looked at how often participants exercised each week to determine if more exercise more effectively reduces risk. Note: This study specifically looked at people assigned female at birth.

Why is this study important?

Early-stage breast cancer is often treatable. Yet, even with successful treatment, some breast cancers come back, often in other organs. Metastatic breast cancer (cancer that returns and spreads) is typically much harder to treat. The uncertainty of whether or when this might happen can cause anxiety.

In addition to treatment, people who have had breast cancer are often willing to make changes in their lifestyles to prevent the disease from coming back. For this reason, studies that look at the effects of diet, exercise and other lifestyle changes are of high importance to people with breast cancer.

Exercise, in particular, is a significant topic of research in breast cancer. Studies have shown its value in improving quality of life, managing side effects, preventing lymphedema and delaying death. Continued research on whether exercise can prevent cancer from returning and spreading is needed.

Study findings

A moderate amount of exercise may help prevent early-stage breast cancer (stages 1-3) from coming back in premenopausal women, especially those with HR-negative breast cancer. The study tracked the time before the cancer returned and spread.

This study included 10,359 people in France with stage 1, 2 or 3 breast cancer who were followed up to six years after diagnosis. Their average age was 56. Some participants were smokers and some were non-smokers. Most had been treated with hormone therapy and more than half were treated with chemotherapy.

Participants completed a questionnaire and self-reported exercise during their study visits (Global Physical Activity Questionnaire-16). The study team conducted the questionnaire with participants and then measured the amount of exercise reported. The amount of exercise was tracked in metabolic task hours/week. The metabolic equivalent (MET) count for each person is based on the rate at which they expend energy relative to their mass while performing some specific physical activity.  For example, a score of 1 indicates inactivity, while a score of 3.5 indicates leisurely biking. The higher the MET count, the greater the intensity of the workout.

Researchers found that:

• Moderate, weekly exercise benefited premenopausal women with HR-negative breast cancer.
• Participants with HR-negative, HER2-positive breast cancer saw the greatest benefit. Their risk of distant recurrence was 63% lower during the study period.
• Participants with triple-negative breast cancer had a 41% lower risk of distant recurrence.
• People who benefited reported exercising between 90 minutes to 5 hours each week.
• Exercising more than 5 hours per week did not add benefit for participants, including people who had already gone through menopause.

Although a significant benefit for people with HR+ breast cancers was not found, the researchers mention that this could be because HR+ participants were not followed long enough. Additional research on this topic would be beneficial.

What does this mean for me?

If you have HR-negative breast cancer and have not gone through menopause, regular moderate exercise may help prevent breast cancer from coming back. If you currently have breast cancer or have had breast cancer in the past, including weekly exercise in your schedule is beneficial.

Exercise has additional benefits beyond cancer. Including moderate exercise in your weekly schedule can help improve your heart health and overall health, both mentally and physically.

Speak with your healthcare provider to make sure that the intensity level of your exercises is ideal for you.

Reference

Soldato D, Michiels S, Havas J, et al. Dose/exposure relationship of exercise and distant recurrence in primary breast cancer. Journal of Clinical Oncology. 2024; 42:3022-3032.

Disclosure: FORCE receives funding from industry sponsors, including companies that manufacture cancer drugs, tests and devices. All XRAYS articles are written independently of any sponsor and are reviewed by members of our Scientific Advisory Board prior to publication to assure scientific integrity.

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posted 11/14/24