Can Step-Based Metrics Predict Current and Future Health-Related Fitness and Patient-Reported Outcomes among Women Diagnosed with Breast Cancer?

ABSTRACT – Purpose – Wearable sensors that track physical activity in daily life may offer insights that help health care providers optimize care plans for individuals with cancer. Therefore, we examined the links between lower health-related fitness and worse patient-reported health and various step-based metrics. Methods – The Alberta Moving Beyond Breast Cancer Study enrolled 1528 women recently diagnosed with breast cancer and measured health-related fitness and patient-reported health outcomes near diagnosis and 1 yr later. Step counts and intensity (cadence, peak steps) were measured by activPAL® over 7 d at baseline. We estimated cross-sectional associations (odds ratios (OR)) at baseline and prospective associations between low baseline stepping and low fitness and poorer health at 1 yr, adjusting for age, demographics, height, weight, and cancer diagnosis/treatment. Results – At baseline, 1408 breast cancer survivors (mean age, 56 yr; early stage (90%)) provided valid activPAL measures (mean, 5.5 d of wear). Taking <5000 steps per day (lower quintile) at baseline was associated with lower aerobic fitness, muscular strength and endurance, lower physical and mental quality of life, and greater fatigue and upper extremity disability at baseline and 1 yr later. Taking <5000 steps per day at baseline was associated with a greater risk of moving from favorable to unfavorable categories of aerobic fitness (OR, 2.64), curlups (OR, 1.84), chest endurance (OR, 2.38), self-reported health (OR, 2.37), physical quality of life (OR, 2.13), and fatigue (OR, 1.81) 1 yr later. Preferred cadence and peak stepping were inconsistently associated after adjustment for total steps. Conclusions – Although our findings need to be replicated, they suggest that simple step counts measured near diagnosis could help health care providers assess the fitness and health status of women recently diagnosed with breast cancer and improve their survivorship care plans.