title: Distribution of metastatic sites in patients with prostate cancer: A population-based analysis.
abstract: BACKGROUND
  There is few data on what constitutes the distribution of metastatic sites in prostate cancer (PCa). The aim of our study was to systematically describe the most common sites of metastases in a contemporary cohort of PCa patients.
  
  
  METHODS
  Patients with metastatic PCa were abstracted from the Nationwide Inpatient Sample (1998-2010). Most common metastatic sites within the entire population were described. Stratification was performed according to the presence of single or multiple (≥ 2 sites) metastases. Additionally, we evaluated the distribution of metastatic sites amongst patients with and without bone metastases.
  
  
  RESULTS
  Overall, 74,826 patients with metastatic PCa were identified. The most common metastatic sites were bone (84%), distant lymph nodes (10.6%), liver (10.2%), and thorax (9.1%). Overall, 18.4% of patients had multiple metastatic sites involved. When stratifying patients according to the site of metastases, only 19.4% of men with bone metastases had multiple sites involved. Conversely, among patients with lymph nodes, liver, thorax, brain, digestive system, retroperitoneum, and kidney and adrenal gland metastases the proportion of men with multiple sites involved was 43.4%, 76.0%, 76.7%, 73.0%, 52.2%, 60.9%, and 76.4%, respectively. When focusing exclusively on patients with bone metastases, the most common sites of secondary metastases were liver (39.1%), thorax (35.2%), distant lymph nodes (24.6%), and brain (12.4%).
  
  
  CONCLUSIONS
  Although the majority of patients with metastatic PCa experience bone location, the proportion of patients with atypical metastases is not negligible. These findings might be helpful when planning diagnostic imaging procedures in patients with advanced PCa.
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, Montreal, Canada; Department of Urology, Urological Research Institute, Vita Salute San Raffaele University, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Gandaglia
authors.forename: Firas
authors.initials: F
authors.lastname: Abdollah
authors.forename: Jonas
authors.initials: J
authors.lastname: Schiffmann
authors.forename: Vincent
authors.initials: V
authors.lastname: Trudeau
authors.forename: Shahrokh F
authors.initials: SF
authors.lastname: Shariat
authors.forename: Simon P
authors.initials: SP
authors.lastname: Kim
authors.forename: Paul
authors.initials: P
authors.lastname: Perrotte
authors.forename: Francesco
authors.initials: F
authors.lastname: Montorsi
authors.forename: Alberto
authors.initials: A
authors.lastname: Briganti
authors.forename: Quoc-Dien
authors.initials: QD
authors.lastname: Trinh
authors.forename: Pierre I
authors.initials: PI
authors.lastname: Karakiewicz
authors.forename: Maxine
authors.initials: M
authors.lastname: Sun
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000453:epidemiology / Q000556:secondary; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000453:epidemiology* / Q000556:secondary*; D001932:Brain Neoplasms / Q000453:epidemiology / Q000556:secondary; D016208:Databases, Factual; D006801:Humans; D007680:Kidney Neoplasms / Q000453:epidemiology / Q000556:secondary; D008113:Liver Neoplasms / Q000453:epidemiology* / Q000556:secondary*; D008175:Lung Neoplasms / Q000453:epidemiology / Q000556:secondary; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011471:Prostatic Neoplasms / Q000473:pathology*; D012189:Retrospective Studies; D013899:Thoracic Neoplasms / Q000453:epidemiology* / Q000556:secondary*; D014481:United States
keywords: bone metastases; metastatic disease; prostate cancer; sites of metastases