Risk of skeletal-related events (SREs) following initial diagnosis of bony metastases in breast, lung, and prostate cancer.

Abstract

e19630 Background: Bony metastases (mets) are a common source of morbidity in patients (pts) with cancer, cause spinal cord compression (SCC), pathological fracture (PF), and bone pain, and often require radiotherapy (RT) and/or surgery to bone (SB). 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 years with primary breast, lung, or prostate cancer diagnosed between 1995 and 2009. Registry and electronic medical records were then used to identify pts with diagnosis of bone mets at initial cancer diagnosis or at recurrence. Trained technicians reviewed medical records for occurrence of SCC, PF, RT and SB—outcomes that have been collectively referred to as SREs. Cumulative incidence of these events was calculated in the presence of competing risk of death. Results: We identified 378 pts with breast cancer and bone mets, 272 with lung cancer and bone mets, and 420 with prostate cancer and bone mets. SREs were present at initial diagnosis of bone mets in 23% of breast cancer pts, 24% of lung cancer pts, and 10% of prostate cancer pts (Table). At 12 months, cumulative incidence of SREs was 57.3% for breast cancer (SCC, 5.1%; PF, 37.9%; SCC and/or PF, 40.2%; SB, 5.9%; RT, 27.4%), 62.7% for lung cancer (SCC, 8.9%; PF, 37.8%; SCC and/or PF, 43.3%; SB, 3.5%; RT, 32.4%), and 38.4% for prostate cancer (SCC, 7.9%; PF, 21.3%; SCC and/or PF, 26.7%; SB, 4.0%; RT, 22.9%). Use of bisphosphonates was largely confined to pts with breast cancer. Conclusions: Though breast, lung, and prostate cancers differ considerably in presentation, clinical course, and treatment, SREs are a common and serious problem in all three cancers among patients with bone mets. [Table: see text]