Risk factors for reduced function in women with a history of breast cancer

Purpose: People with a history of breast cancer are at risk of losing function during and after treatment. Unfortunately, little is known about the individual and additive effects of specific treatment, disease-related, and demographic factors that may contribute to functional decline. This manuscript reports the results of a multi-center study to evaluate the effects of these factors on function. Methods: In this cross-sectional study, women with a history of breast cancer referred to physical medicine and rehabilitation cancer rehabilitation clinics were administered the PROMIS® Cancer Function Brief 3D Profile to evaluate function in the domains of physical function, fatigue, and social participation. Clinical and demographic information, including treatment history and disease status, was recorded by clinicians. Patients were analyzed in two groups: those with active disease on antineoplastic treatment, and those with no evidence of disease (NED). A multivariable model was constructed to detect associations between clinical and demographic factors. Results: In patients with NED, the presence of chemotherapy-induced peripheral neuropathy (CIPN) was strongly associated with reduced function in all three domains. In those with active disease, having brain metastases was significantly associated with reduced function in all domains and CIPN with reduced physical function. Radiation was associated with improved function in both cohorts. Conclusions: Among women seeking rehabilitative care, CIPN and the presence of brain metastases were most strongly associated with a decline in function. The effects of radiation on function were unexpected and may be partially explained by the treatment’s role in symptom management. Clinicians who treat breast cancer should consider a patient’s functional status when providing supportive care.