Aim:
Healthy levels of physical activity have shown better quality of life outcomes and improved survival in women with breast cancer. This study aimed to define baseline fitness levels in a culturally and linguistically diverse outpatient breast clinic.
Methods:
N=200 women aged 18-85 were surveyed on their general health status and details of treatments for those with a breast cancer diagnosis. A validated 6-minute walk test (6MWT) was then performed on a single-turn 30m walking track. Single and multiple linear regression models were performed with analysis of variance.
Results:
The mean 6-minute walk distance (6MWD) was 486.6m (95%CI±12.8m), which is comparable with reference ranges. The mean age of participants was 47.5 (range 18-85). N=97(48.5%) participants had a diagnosis of breast cancer. Breast cancer diagnosis had a negative effect on 6MWD of -33.6m walked (SE=12.8m, p=0.010). Body mass index (BMI) had a negative effect on 6MWD of -4.2m walked per unit of BMI increase (SE=1.0m, p<0.001). The presence of any major medical comorbidity also had a negative effect on 6MWD of -56.9m walked (SE=14.7m, p<0.001). Smoking was not associated with a difference in 6MWD. Multiple regression analysis showed that only age, BMI and presence of comorbidities but not breast cancer had statistically significant effects on 6MWD. Self-reported exercise tolerance correlates significantly with 6MWD, but this may be clinically irrelevant because there is a high degree of variance.
Conclusion:
The 6MWT was easily performed within the outpatient environment during routine clinics and a set of baseline fitness data has been established for patients attending a breast clinic. No set of variables predicts 6MWD well; the combination of age and BMI performed better than any single self-reported measure. This indicates that the 6MWT provides additional information from the general health status and self-reported measures and can be a valuable assessment tool in the outpatient setting. We now plan to incorporate the 6MWT into routine clinic use. This will allow us to identify changes in fitness during cancer treatments and make appropriate referrals for prescribed exercise interventions in our Breast Cancer population.