Burden of Skeletal-Related Events (SRES) in Patients (PTS) with Solid Tumors: Results of the Stars Observational Study in the US vs EU

ABSTRACT Background The STARS study was a prospective, multicenter, international, observational study designed to measure the burden of SREs (radiation or surgery to bone, pathologic fracture, or spinal cord compression) in pts with advanced cancer and bone metastases. Here we report results in pts with solid tumors by geographical region for US vs EU (Germany, United Kingdom, Spain, and Italy). Methods This analysis included pts with bone metastases secondary to breast, prostate, or lung cancer and ≥1 SRE in the 97 days before enrollment (05/08 – 05/10). Data on SREs and health resource utilization (HRU), including inpatient stays, outpatient visits, emergency room visits, nursing home/long-term care facility stays, home health visits, procedures, and certain medications, were collected retrospectively for the 97 days before enrollment and prospectively for up to 21 months. Investigators were responsible for attributing HRU to each SRE. Results US = 190 pts with 354 SREs; EU = 478 pts with 893 SREs. Baseline demographics and disease characteristics were similar for US and EU. Inpatient stays were more frequent in EU compared with US, and the length of stay was longer in EU (table). Outpatient visits were more frequent in US vs EU, while emergency room visits were similar between regions. Nearly every SRE was associated with a procedure in both regions; however, the number of procedures per SRE was higher in US, which was in part due to a much greater number of external beam radiation procedures per SRE in US likely reflecting standard use of multi-fraction radiation. Slightly more pts were receiving bisphosphonates at/before enrollment in US compared with EU, and pts in US received IV bisphosphonates sooner than in EU. Conclusion The HRU burden of SREs was substantial in both US and EU. Some regional differences were observed, particularly with respect to hospitalization, length of stay, and time to receipt of IV bisphosphonates. HRU US (n = 354) * EU (n = 893) * Inpatient Stays (IS) Proportion of SREs with IS Number/SRE 14.7% 29.5% Mean 0.18 0.32 Median Length of Stay (days) 0.0 0.0 Mean 10.6 19.9 Median 7.0 17.0 Outpatient Visits (OV) Proportion of SREs with OV Number/SRE 88.1% 74.1% Mean 9.1 4.8 Median 9.0 2.0 Emergency Room Visits (ERV) Proportion of SREs with ERV Number/SRE 4.0% 4.1% Mean 0.05 0.04 Median 0.0 0.0 Inpatient/Outpatient Procedures (P) Proportion of SREs with P Number/SRE 95.5% 96.4% Mean 11.3 6.9 Median 12.0 5.0 Bisphosphate (BP) Use Proportion of pts receiving oral or IV BP 70.0% 63.0% at or before enrollment Time from diagnosis of bone metastasis to first IV BP use (months), median ** 1.8 6.7 * n = number of SREs; ** **Kaplan-Meier estimate Disclosure I. Duran: Advisory Board Member, Amgen. A. Bahl: Advisory Board member Amgen, Novartis. G. Hechmati: Employee of Amgen and owns Amgen stock. R. Wei: Employee of Amgen and owns Amgen stock. C. Atchison: Employee of Amgen and owns Amgen stock. All other authors have declared no conflicts of interest.