Trends of skeletal related events in patients with breast cancer metastasized to bone.

Abstract

1098 Background: Up to three-quarters of women with advanced breast cancer develop bone metastases, predisposing to Skeletal Related Events (SRE), which are associated with a significant health care burden, poor prognosis, loss of functional independence and a decrease in quality of life. We performed a retrospective analysis on predictors of SRE in this population. We also evaluated temporal trends of outcomes and resource utilization in those with SRE. Methods: Adult breast cancer patients with metastases to bone, admitted from January 2012 to September 2015 were identified from the Nationwide Inpatient Sample database. Based on previous studies, SRE was defined by using ICD-9 codes for pathologic fracture, spinal cord compression, necessity for radiation to bone or surgery to bone. Multivariable analysis of predictors of SRE in patients with breast cancer metastatic to bone, as well as mortality in the SRE group were performed. Temporal trends of resource utilization across the years were evaluated. Results: A total of 143,455 patients with breast cancer with metastases to bone were identified, of which 17.2% had SRE. Patients with SRE had a mean age of 66 years and were predominantly white (70.2%). After adjusting for confounders, African Americans and Hispanics were less likely than Whites to develop SRE. On multivariable analysis, only comorbidity burden (in the form of high Charlson comorbidity index) predicted inpatient mortality. Rates of SRE in breast cancer patients with bone metastases did not change over the years (17.2% to 17.1%). Inpatient mortality of patients with SRE remained stable (3.76% to 3.79%). There was a statistically significant increase in surgical intervention (43.4% to 47.7%, p<0.01) and decrease in radiation to bone (25.7% to 19.7%, p<0.001) over time. Length of hospital stay and total hospital charges, after adjusting for inflation, remained largely unchanged. Conclusions: Incidence of SRE, inpatient outcomes and health care costs remained stagnant in those with metastatic breast cancer between 2012 and 2015, despite the advent of novel bone-targeted agents. There has been an increased trend towards surgical intervention and less utilization of local radiation over time. [Table: see text]