The effects of exercise on cancer-related fatigue in breast cancer patients during primary treatment: a meta-analysis and systematic review

ABSTRACT

Introduction

Cancer-related fatigue is one of the most prevalent symptoms reported by breast cancer survivors. Despite a corpus of literature dedicated to understanding and identifying evidence-based treatments for cancer-related fatigue, gaps in the literature remain, particularly for breast cancer survivors during their primary treatment. Exercise training may represent an efficacious behavioral modality for mitigating fatigue symptoms in cancer survivors; yet, the effects of exercise during adjuvant therapy is an understudied area.

Areas covered

In this review, we synthesize the most recent evidence of exercise’s effects on cancer-related fatigue during active treatment for breast cancer. We summarize the overall effects of exercise, moderators of these effects, and areas requiring further research.

Expert opinion

Strong evidence supports at least modest effects of exercise on cancer-related fatigue during breast cancer treatment. However, several knowledge gaps persist, including the need to: risk stratify patients to tailor exercise promotion strategies; implement higher-quality studies and translate this evidence to clinical practice; adopt biobehavioral models to better understand exercise’s effects on cancer-related fatigue; evaluate the effects of exercise modes besides aerobic and combined training; and integrate technology to better understand and promote fatigue-reducing behaviors, such as exercise, across cancer care.

KEYWORDS:

• Exercise
• physical activity
• breast cancer
• cancer-related fatigue
• meta-analysis

Article highlights

• Cancer-related fatigue remains one of the most prevalent and debilitating symptoms among breast cancer survivors

• Recent randomized controlled trials indicate that exercise during treatment has significant, but modest effects on cancer-related fatigue in breast cancer survivors undergoing active treatment

• The moderating effects of intervention length, cancer treatment modality (e.g. during chemotherapy versus radiation therapy), and exercise mode remain equivocal

• Supervised and unsupervised exercise programs demonstrated similar benefits to fatigue, while high-quality studies demonstrated stronger benefits compared to medium- and low- quality studies

• Exercise training is beneficial for reducing cancer-related fatigue; however, further research to better understand effect moderators and biobehavioral mechanisms is needed

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.