Pathologic fracture in metastatic kidney cancer: Identifying widening disparities and opportunity for quality improvement

Background: Management and palliation of pathologic fracture (PFx) secondary to metastatic prostate (mCaP) and renal cancer (mRCa) is hospital resource intensive. Using a national all-payer database, we assessed the burden of PFx secondary to mCaP and mRCa nationwide. Admission rates, mortality, surgical fixation rates, and risk factors for high-cost admissions for pathologic fractures were assessed Methods: National Inpatient Sample was queried from 2013 to 2015 for mCaP and mRCa admissions. Hospitalization costs of PFx was assessed over time by cancer type. Hospitalization outcomes were stratified by cancer type. Multivariable logistic regression models were constructed to examine predictors of high-cost admission for PFx (>75th percentile). Results: From 2013 to 2015, there were 21,466 and 6,334 admissions for mCaP and mRCa with bone metastasis, respectively. Proportion of admissions for PFx was greater in mRCa than mCaP (15.9% vs. 7.2%, P < 0.01). PFx secondary to mRCa was associated with longer length of stay, hospitalization cost, and greater rate of surgical fixation. Costs of admission for PFx increased by $4,005 dollars from 2013 to 2015 for mRCa (P = 0.03), but did not increase for mCaP (P = 0.5). On multivariable analysis, mRCa was associated with greater odds of PFx (OR:2.12, P < 0.01), and high-cost hospitalization for mRCa associated PFx (OR:1.37, P = 0.02). Conclusions: PFx secondary to mRCa represents a significant health care burden. mRCa was associated with greater odds of PFx compared to mCaP, as well as greater inpatient morbidity and cost. Formalized guidelines on screening and management of bone lesions in mRCa may be needed to mitigate this under-recognized health care burden.