Meta-analysis of the effects of exercise intervention on quality of life in breast cancer survivors

Breast cancer is the most common type of cancer among women worldwide. Diagnosis and treatment of breast cancer pose an array of physical and psychological threats to the survivors. Exercise interventions may be particularly appropriate for cancer survivors because they have the potential to improve physical and psychological functioning. The review aims to examine the effectiveness of exercise intervention on the quality of life (QOL) of breast cancer survivors. Five databases (Medline, CINAHL, Scopus, The Cochrane Library, and CAJ Full-text Database) were searched from 2003 to July 2013. Clinical controlled trials of exercise interventions for breast cancer survivors who were at least 18 years old and had completed active cancer treatment were included. A total of 25 trials were included in this study, of which 19 were pooled together statistically. Subjects in the exercise interventions had higher overall QOL than subjects in the control group. The standardized mean difference (SMD) for changes in overall general QOL scores was 0.70 (95 % CI 0.21, 1.19). The SMD for changes in cancer-specific QOL scores was 0.38 (95 % CI 0.03, 0.74). For cancer-specific QOL domains, there were positive but non-significant trends in two QOL domains (breast symptoms: Z score = 1.12, p = 0.26; arm symptoms: Z score = 1.32, p = 0.19). This study provides updated findings supporting the idea that exercise interventions have statistically significant effects on overall QOL in breast cancer survivors, as well as positive trends for cancer site-specific QOL domains (breast and arm symptoms).