Epidemiology of bone metastases

Background: This study evaluated the incidence of de novo bone metastasis across all primary cancer sites and their impact on survival by primary cancer site, age, race, and sex. Questions/purposes: Our objectives were (I) characterize the epidemiology of de novo bone metastasis with respect to patient demographics, (II) characterize the incidence by primary site, age, and sex (2010–2015), and (III) compare survival of de novo metastatic cancer patients with and without bone metastasis. Methods: This is a retrospective, population-based study using nationally representative data from the Surveillance, Epidemiology, and End Results program, 2010–2015. Incidence rates by year of diagnosis, annual percentage changes, Kaplan-Meier, univariate and multiple Cox regression models are included in the analysis. Results: Of patients with cancer in the SEER database, 5.1% were diagnosed with metastasis to bone, equaling ~18.8 per 100,000 bone metastasis diagnoses in the US per year (2010–2015). For adults >25, lung cancer is the most common primary site (2015 rate: 8.7 per 100,000) with de novo bone metastases, then prostate and breast primaries (2015 rates: 3.19 and 2.38 per 100,000, respectively). For patients <20 years old, endocrine cancers and soft tissue sarcomas are the most common primaries. Incidence is increasing for prostate (Annual Percentage Change (APC) = 4.6%, P < 0.001) and stomach (APC = 5.0%, P = 0.001) cancers. The presence of de novo bone metastasis was associated with a limited reduction in overall survival (HR = 1.02, 95%, CI = [1.01–1.03], p < 0.001) when compared to patients with other non-bone metastases. Conclusion: The presence of bone metastasis versus metastasis to other sites has disease site-specific impact on survival. The incidence of de novo bone metastasis varies by age, sex, and primary disease site.