Assessment Of Renal Function Among Patients With Bone Metastases From Solid Tumors

To examine the change in renal function among patients with bone metastases (BM) from solid tumors (ST) A retrospective cohort study was conducted using OSCER (Oncology Services Comprehensive Electronic Records) database, containing electronic medical records from >50 outpatient oncology/hematology practice groups in the US. The study sample included adults (age >= 18 years) diagnosed with a single ST and BM between 01/01/2012 through 09/30/2013. Changes in renal function from baseline (6 months prior to the BM diagnosis) over the follow-up period were assessed. The outcomes of interest include clinically-meaningful increase in serum creatinine (SeCr) [defined as 0.5 mg/dL increase in patients with normal baseline levels (<1.4 mg/dL), and 1.0 mg/dL increase in those with elevated baseline levels (≥1.4 mg/dL)], estimated glomerular filtration rate (eGFR), and chronic kidney disease (CKD) stage (1: eGFR>90 to 5: eGFR<15). Descriptive analysis was conducted to examine baseline patient characteristics and change in renal function. A total of 6,380 patients met the eligibility criteria; majority of them were female (52%), Caucasian (70%), with mean age of 67 years (Standard Deviation [SD]: 12), mean SeCr of 1.0 (SD: 0.5), and mean eGFR of 77 (SD: 23) at baseline. During a median follow-up of 191 days after BM diagnosis, an average 11-point (SD: 17) reduction (relative reduction: 13%) in eGFR from baseline was observed. Clinically-meaningful increases in SeCr were observed in 10.8% of the patients overall; among 7.2% patients from elevated (n=706) and 11.3% from normal (n=5,674) baseline SeCr levels. Increases in CKD stage from baseline levels were observed in 36% of the patients. Worsened renal function was observed among patients with ST and BM. Given the use of bone targeting agents in this patient population, future analysis is needed to understand the impact of those agents, such as zoledronic acid, on renal function.