LAUSR

12115 Background: In the United States, an estimated 1 in 8 women will be diagnosed with breast cancer during her lifetime. Of those with metastasis, over half have bone metastases leading to risk for pathological fractures. Further, approximately 1 in 4 women over 65 years have osteoporosis of the femur neck or lumbar spine. We performed a retrospective analysis on outcomes in pathological fractures secondary to breast cancer metastasis in comparison to osteoporosis, including disposition at discharge. Methods: The Nationwide Inpatient Sample (NIS) database was queried to include all adult women admitted with osteoporotic fractures and pathological fractures due to metastatic breast cancer between 2016 and 2018. T-test was used to compare means of continuous variables and chi-square test to compare proportions of categorical variables. Multivariate analysis of predictors of pathological fractures in women with breast cancer metastatic to bone, as well as mortality, resource utilization and disposition in this group were performed. Results: A total of 91,494 fractures, combining osteoporosis and pathological fractures secondary to metastatic breast cancer were identified, of which the latter accounted for 4.9%. Patients with pathologic fractures secondary to metastatic breast cancer were younger (mean age 62.8 vs 79.5 years, p < 0.0001) and were more likely to be black (14.6% vs 3.1%, p < 0.0001) or Hispanic (8.3% vs 4.7%, p < 0.0001). Adjusting for demographic variables and comorbidity burden, pathological fractures secondary to metastatic breast cancer were not associated with a significant increase in inpatient mortality (aOR 1.57, 95% CI 0.84-2.95, p = 0.16), but were independently associated with increased length of hospital stay by 0.7 days per admission (p = 0.01) and higher hospitalization costs by $3,381 USD per admission (p < 0.01). Regarding disposition, patients with pathological fractures secondary to breast cancer were less likely to be discharged to a nursing facility (aOR 0.57, 95% CI 0.48-0.68, p < 0.001) and were more likely to be transitioned to home health care (aOR 1.46, 95% CI 1.20-1.78, p < 0.001). Conclusions: In adult women, pathological fractures secondary to breast cancer are less frequent than osteoporotic fractures and were not independent predictors of inpatient mortality. They do however prolong length of stay and increase healthcare costs. Further efforts should focus on risk prediction and prophylactic management of high risk bone lesions in order to enhance patient’s quality of life, decrease hospitalization admissions, stay and cost.