27 The search identified 1978 papers, of which 361 were retrieved and screened for eligibility and 85 met our inclusion criteria (Figure 1). A full list of included studies can be found in Appendix 2 (in the eAddenda). The most common reasons for exclusion were that the outcomes assessed did not meet the inclusion criteria, or the studies did not examine women diagnosed with breast cancer. Study designs and relevant participant
characteristics are listed in Table 1. Of the studies included, 42 were randomised trials, 19 were non-randomised intervention studies, and 24 were observational studies with no intervention. The majority of studies (n = 61) included women who were off treatment, while others included women following surgery but before chemotherapy/radiation therapy (n = 20) and/or during chemotherapy/radiation therapy (n = 9), and for the purposes of the find more present review were classified as on treatment (n = 28). Some observational studies included assessments at multiple time points and were included in both groups. Normative values for comparison are presented in Table 2. The most common test used to assess aerobic capacity was a maximal cardiopulmonary exercise test (n = 16) using either a cycle ergometer (n = 9) or treadmill (n = 8) protocol (see Table 3 in the eAddenda). Pooled relative
VO2peak was a mean of 23.7 mL/kg/min (95% CI 20.4 to 27.0) for women on treatment and 22.8 mL/kg/min (95% CI 20.7 to 24.9) for women off treatment (Figure 2). The pooled absolute VO2peak was a mean of 1.65 L/min (95% CI: 1.59 to 1.72) from study groups on treatment and 1.60 L/min (95% CI 1.48 to 1.72) from study Paclitaxel mouse groups off treatment (Figure 3). Compared to published normative data, pooled means of VO2peak fell into the ‘very
Tolmetin poor’ category for women age 50 to 59 (Table 2).11 No heterogeneity was identified (all I2 values < 30%). Submaximal exercise tests were used to predict VO2max in 15 studies, more commonly using a treadmill (n = 12) than a cycle ergometer (n = 3) protocol. Predicted VO2max values tended to be higher than measured VO2peak. The pooled mean for predicted VO2max for women on and off treatment was 25.2 mL/kg/min (95% CI 19.1 to 31.3) and 23.9 mL/kg/min (95% CI 22.5 to 25.4), respectively (Figure 4). These mean values fall into the ‘very poor’ category for women age 50 to 59 (Table 2).11 No heterogeneity was identified (all I2 values < 30%). The 6MWT was used as a measure of aerobic capacity in nine studies. The pooled mean value for distance walked was 523 m (95% CI 499 to 548) for women on treatment, and 500 m (95% CI 476 to 524) in women off treatment (Figure 5). These pooled means fall between the 25th and 50th percentiles of community-dwelling adults aged 60 to 64 (Table 2).28 The 12MWT was used in 11 studies. The pooled mean value for distance walked was 1020 m (95% CI 982 to 1058) in women on treatment and 904 m (95% CI 831 to 976) in women off treatment (Figure 6).