1793PUse of skeletal-related events preventive agents in patients with solid tumours and bone metastases in central Denmark

Abstract Background Bone metastases (BM) are common in patients with solid tumours, especially breast, prostate and lung cancer. Patients with BM may experience skeletal-related events (SRE) including pathological fractures and spinal cord compression. Bisphosphonates and denosumab, known as SRE preventive agents (SPA), are indicated for patients with BM and are recommended by ESMO guidelines. However, data on the clinical use of these agents are lacking. The aim of this study was to estimate the proportion of SPA- and SRE-naive patients receiving SPA treatments at SRE preventive doses following BM diagnosis. Methods Adult patients with solid tumours, a record of BM and no record of SPA treatment or an SRE before the first-recorded BM were identified from March 2011 to June 2016 in the Danish National Patient Registry or Danish Cancer Registry. The proportion of patients receiving hospital-administered SPA, identified via the Health Services Database of the Central Denmark Region, was calculated over the 6-month period after their first-recorded BM diagnosis along with the 95% confidence interval (CI). Follow-up was until death or December 31, 2016. Results A total of 2,556 eligible patients were included (m/f 1501/1055; median age 70 years (IQR 63–77). SPA treatment was recorded for 822 (32%) patients, mainly before the development of an SRE (86%, n = 706), in contrast to post-SRE (14%, n = 116). Across all solid tumours, a greater proportion of younger than older patients received SPA treatment. Receipt of SPA before an SRE varied by cancer site: lung (50%, 95% CI 46%–54%), breast (42%, 95% CI 37%–47%), prostate (3%, 95% CI 2%–5%), and other solid tumours (20%, 95% CI 18%–23%). Median [IQR] time from first-recorded BM diagnosis to first SPA before an SRE also varied by cancer site: breast (22 [7, 51] days), lung (6 [3, 26] days), prostate (43 [17, 57] days) and other solid tumours (24 [5, 44] days). Conclusions In this descriptive study, variations in the use of SPA for SRE prevention in routine clinical settings were observed across different solid tumours, warranting further cancer-specific investigations while accounting for patients’ characteristics. Clinical trial identification Amgen study 20160169. Legal entity responsible for the study Amgen (Europe) GmbH. Funding Amgen (Europe) GmbH through an institutional grant; administered by Aarhus University. Disclosure J. Acquavella: Shareholder / Stockholder / Stock options; JA retired from Amgen in 2014. A.M. Seesaghur: Shareholder / Stockholder / Stock options, Full / Part-time employment: Amgen; Shareholder / Stockholder / Stock options, Full / Part-time employment: Amgen. R.K. Hernandez: Shareholder / Stockholder / Stock options, Full / Part-time employment: Amgen. V. Ehrenstein: Full / Part-time employment; VE is a salaried employee of Aarhus University and has nothing to declare. All other authors have declared no conflicts of interest.