Muscle Strength, Body Composition, and Physical Activity in Women Receiving Chemotherapy for Breast Cancer

Abstract

There is evidence to suggest that treatment of breast cancer with chemotherapy can induce metabolic changes in skeletal muscle. Women undergoing treatment for breast cancer with certain chemotherapeutic agents can experience declines in lean body mass and muscle strength and a subsequent increase in body weight. These alterations not only can lead to declines in physical function but also predispose women to weight-related chronic illness. Excess body weight may also play a role in the development or recurrence of breast cancer. There is evidence that physical exercise may improve body composition and enhance muscular endurance, flexibility, and quality of life (QOL) in women with breast cancer. While studies of aerobic, resistance, and combinations of aerobic and resistance exercise for women with breast cancer have been conducted, most studies employed supervised aerobic exercise sessions. Few studies have examined the role of resistance exercise or the combination of resistance and aerobic exercise in maintaining or increasing muscle strength while preserving lean body mass in this population. The relatively small sample sizes and short duration of physical activity interventions in previous studies make it difficult to detect dose responses to exercise training. Physical activity interventions with larger sample sizes and of longer duration are necessary to achieve longterm health outcomes. Physical activity interventions that include the older or more obese women with breast cancer are also needed, as this population may be most at risk of functional decline and the development of chronic illness. Interventions appropriate for women treated for breast cancer who have comorbid disease are also needed. Newer, more intense chemotherapy regimens may induce a differential effect on muscle strength and body composition. However, the role of physical activity during dose-dense chemotherapy protocols has not been established. Keywords: breast cancer; muscle strength; body composition; physical activityThe role of exercise and physical activity in cancer prevention, recovery, and rehabilitation has been the focus of much recent literature. In terms of cancer prevention, physical activity and exercise have been touted as part of a healthy lifestyle that can reduce the incidence of obesity-related chronic illnesses, cancer, and cancer recurrence. However, the mechanism by which physical activity or exercise exerts its effect and the amount of activity necessary remains unknown. There is evidence that physical exercise may improve body composition and enhance muscular endurance, flexibility, and quality of life (QOL) in women with breast cancer. However, most studies of exercise and cancer survivorship have been limited by small sample sizes, similar cancer disease stages, the use of single-modality exercise regimens, and limited duration of follow-up. Investigations of breast cancer disease and treatment side effects on muscle strength and body composition have been limited. The purpose of this article is to examine t...

Rehabilitation in patients with radically treated respiratory cancer: A randomised controlled trial comparing two training modalities

“…Surgery, chemotherapy, and radiation therapy are known to decrease exercise capacity, muscle strength and QoL in lung cancer patients [15,17,20,27,28,35,36]. The results of the present study are in line with previously reported data.…”

Efectividad del ejercicio físico en la fatiga de pacientes con cáncer durante el tratamiento activo: revisión sistemática y metaanálisis

“…El ejercicio físico es considerado una intervención no farmacológica eficaz en la promoción del bienestar físico, mental y funcional de pacientes con cáncer 10,11,12 . Cramp & Byron 13 en una revisión sistemática encontraron que el ejercicio físico produjo mejoras significativas en la fatiga de pacientes con cáncer durante y después del tratamiento activo; aunque los autores no realizaron estimaciones del efecto de las modalidades de ejercicio estudiadas.…”

Is bra discomfort a barrier to exercise for breast cancer patients?

“…Studies have also shown promising effects of physical activity on fatigue, physical function, physical capacity and muscular fitness during, and after cancer treatment [5,[10][11][12][13]. In particular, breast cancer patients who exercise have reported decreased levels of anxiety and depression, coupled with overall mood elevation [3].…”