Hospitalizations for fracture in patients with metastatic disease: Primary source lesions in the United States

Background Breast, lung, thyroid, kidney, and prostate cancers have high rates of metastasis to bone in cadaveric studies. However, bone metastasis at time of death may be less clinically relevant than occurrence of pathologic fracture and related morbidity. No population-based studies have examined the economic burden from pathologic fractures. Objectives To determine primary tumors in patients hospitalized with metastatic disease who sustain pathologic and nonpathologic (traumatic) fractures, and to estimate the costs and lengths of stay for associated hospitalizations in patients with metastatic disease and fracture. Methods The Healthcare Cost and Utilization Project’s National (Nationwide) Inpatient Sample was used to retrospectively identify patients with metastatic disease in the United States who had been hospitalized with pathologic or nonpathologic fracture during from 2003-2010. Patients with pathologic fracture were compared with patients with nonpathologic fractures and those without fractures. Results Of 674,680 hospitalizations of patients with metastatic disease, 17,313 hospitalizations were for pathologic fractures and 12,770 were for nonpathologic fractures. The most common primary cancers in patients hospitalized for fractures were lung (187,059 hospitalizations; 5,652 pathologic fractures; 3% of hospitalizations were for pathologic fractures), breast (124,303; 5,252; 4.2%), prostate (79,052; 2,233; 2.8%), kidney (32,263; 1,765; 5.5%), and colorectal carcinoma (172,039; 940; 0.5%). Kidney cancer had the highest rate of hospitalization for pathologic fracture (24 hospitalizations/1,000 newly diagnosed cases). Patients hospitalized for pathologic fracture had higher billed costs and longer length of stay. Limitations Hospital administrative discharge data includes only billed charges from the inpatient hospitalization. Conclusion Metastatic lung, breast, prostate, kidney, and colorectal carcinoma are commonly seen in patients hospitalized with pathologic fracture. Pathologic fracture is associated with higher costs and longer hospitalization. Funding Grants from the NIH (K08 AR060164-01A), American Society for Surgery of the Hand Hand Surgeon Scientist Award grant, and University of Rochester Medical Center Clinical & Translational Science Institute grants, in addition to institutional support from the University of Rochester and Pennsylvania State University Medical Centers.