Objective Assessment of Physical Activity During Chemotherapy for Breast Cancer

Over 3.1 million women are currently living with a diagnosis of breast cancer in the United States (US), representing 41% of all female cancer survivors in the US. The increased breast cancer survival rate has necessitated a shift in cancer care toward developing interventions to empower patients to improve their quality-of-life, and perhaps prognosis, during and after treatment. Among women diagnosed with early-stage (I or II) breast cancer, around 40% will receive chemotherapy. Among women diagnosed with late-stage (III or IV), around 75% will receive chemotherapy. Adjuvant chemotherapy is associated with many side effects, including fatigue, nausea, disturbed sleep, decreased activity, and weight gain. Women receiving chemotherapy gain an average of 2.5 to 6.2 kg during therapy. Weight gain increases the risk of breast cancer recurrence and mortality, as well as cardiovascular disease, diabetes, and second primary cancers. Physical activity alleviates or reduces both short and long term treatment side effects of chemotherapy, including weight gain, and restores physical functioning in breast cancer patients. Additionally, randomized controlled trials in breast cancer patients have shown that adding exercise to chemotherapy programs can improve breast cancer outcomes.

Although there are many benefits of engaging in physical activity during cancer treatments, activity levels typically decline throughout treatment. Existing research has relied on self-reported activity levels, which is a poor measure of low-intensity activities and can only capture a periodic snap shot of activity levels. This study will provide objective physical activity data across the entirety of the patient's chemotherapy treatments. This in depth data will provide a new perspective on the patterns of activity levels and help to identify if there are critical times in which to intervene to prevent physical activity declines.