Risk of skeletal-related events (SREs) in patients with prostate cancer (PC) and newly diagnosed metastases to bone.

Abstract

e15197 Background: Bone is a common site of metastatic involvement in patients (pts) with PC. Bony metastases (mets) are often associated with SREs (spinal cord compression [SCC], pathologic fracture [PF], surgery to bone [SB], radiotherapy to bone [RT]). Skeletal complications cause significant morbidity and mortality. Current estimates of SRE risk come principally from randomized clinical trials. Information from routine clinical practice is limited. Methods: Using the tumor registry and electronic data stores at a large U.S. Midwest healthcare system that serves approximately 800,000 persons, we retrospectively identified all pts aged ≥18 yrs with primary PC and newly diagnosed bone mets between 1/1/95 and 12/31/09. Electronic medical records were reviewed by trained abstractors for evidence of SREs between date of bone mets diagnosis and death, loss to follow-up, or end of study for evidence of first SRE. Cumulative incidence of SREs was estimated in the presence of competing risk of death. Results: We identified a total of 420 men with primary PC and newly diagnosed bone mets; 42 pts had evidence of SREs at initial diagnosis of bone mets and were excluded from the analyses. Among the remaining 378 pts, mean (SD) age was 72.7 yrs (9.8 yrs); 38% were Caucasian and 58% were African-American. Median duration of follow-up after diagnosis of bone mets was 17.1 months (mos). At 12 mos, cumulative incidence of SREs was 31.6% (SCC, 6.1%; PF, 15.0%; SCC and/or PF, 19.1%; SB, 3.9%; RT, 24.4%) (Table). Corresponding figures at 24 mos were 45.3% (SCC, 12.5%; PF, 22.2%; SCC and/or PF, 30.2%; SB, 6.2%; RT, 34.9%). Relatively few pts (14.6%) received intravenous bisphosphonates prior to SRE. Conclusions: Pts with PC in routine clinical practice are at high risk of SREs following initial diagnosis of bone mets. [Table: see text]