Imaging and clinical characteristics predict near-term disablement from bone metastases: Implications for rehabilitation

Objective To distinguish which patients with bone metastases are at risk for near-term disablement in order to assist clinicians in assessing the appropriateness of referrals for rehabilitation services. Design Prospective cohort study. Setting National Cancer Institute-designated comprehensive cancer center imbedded in a tertiary medical center. Participants Data were collected from members (n=78) of a patient cohort (N=311) with stage IIIB or IV non-small-cell lung cancer or extensive-stage small-cell lung cancer who developed new or progressive imaging-confirmed bone metastases during the 2-year course of the study. Interventions Not applicable. Main Outcome Measures Functional capabilities were assessed at 3- to 4-week intervals over the study's 2-year duration with the Activity Measure for Post-Acute Care Computer Adaptive Testing. Results Seventy-eight participants developed new or progressive bone metastases during the study. Most were men, and 83% had non-small-cell lung cancer. Metastases were most frequently located in the ribs (n=62), pelvis (n=49), or the thoracic (n=60) and lumbar spine (n=44). While neither the number of bone metastases nor their specific location was associated with near-term changes in patient mobility, their association with pain or a focal neurologic deficit was strongly associated with large declines in mobility. Similarly, patients whose imaging studies revealed new metastases and the expansion of established metastases were more likely to lose mobility. Conclusions The total burden, specific locations, and overall distribution of bone metastases did not predict disablement. Patients with lung cancer-associated bone metastases are at markedly increased risk for declining mobility when their metastases are expanding in size and increasing in number, or are associated with pain or with new neurologic deficits.