Can the Six-Minute Walk Test Be Used to Individualize Physical Activity Intensity in Patients with Breast Cancer?

SIMPLE SUMMARY: Physical activity has proven to be effective in breast cancer patients. Appropriate exercise intensity for each patient is necessary to maintain this practice in patients with possible comorbidities and potential adverse events of specific treatments. These programs should be proposed to many patients so to prescribe the adapted program; this will necessitate easy and cost-effective tests. It is useful to use an adapted target heart rate (HR) to prescribe exercise intensity. In this work, we assessed the potential equivalence of the ventilatory threshold HR obtained during a cardiopulmonary exercise test and the HR measured over the last 3 min of the six-minute walk test (6MWT-HR). At baseline, the 6MWT-HR was in good agreement and showed moderate but statistical correlation with the VT-HR in breast cancer patients. The best correlation between these two tests was obtained after the APA program and chemotherapy. These results were independent of body mass index. The 6MWT is useful to prescribe APA programs before and also after chemotherapy concomitant with physical activity. ABSTRACT: Background: Adapted physical activity (APA) aids breast cancer patients. It is necessary to use an adapted target heart rate (HR) when prescribing exercise intensity. Methods: In total, 138 patients previously included in two published randomized clinical trials underwent the CPET and 6MWT before and after adjuvant therapy. Of these patients, 85 had performed APA, and 53 had received only the usual therapy. HRs were recorded during the two tests. Results: Before starting chemotherapy, good agreement (intraclass correlation (ICC) 0.69; confidence interval at 95% IC(0.95) (0.591–0.769); p < 0.001) and a moderate correlation were evident between the 6MWT-HR and ventilatory threshold HR of the CPET (r = 0.70; p < 0.001). Good agreement and a high positive correlation were noted only in the group who engaged in APA (ICC 0.77; IC(0.95) (0.659–0.848); p < 0.001; r = 0.8; p < 0.01); moderate agreement and a moderate positive correlation were apparent in the control group (ICC 0.57; IC(0.95) (0.329–0.74); p < 0.001; r = 0.6; p < 0.01). The correlations were independent of age and body mass index. Conclusions: The 6MWT-HR can be used to prescribe exercise intensity for breast cancer patients both before and after specific treatment with concomitant APA.