title: The relationship between lung cancer histology and the clinicopathological characteristics of bone metastases.
abstract: Lung cancer is the leading cause of death due to cancer, and bone is one of the most frequent sites of metastasis. However, there is no published evidence regarding an association between lung cancer histology and skeletal complications. Therefore, we evaluated the influence of lung cancer histology on the frequency of bone metastases (BMs), skeletal-related events (SREs), and survival after BM.
  
  
  
  This retrospective study evaluated medical records from 413 patients who were diagnosed with lung cancer between 2003 and 2012. The prevalences of BMs and SREs were calculated, and their associations with the histological subtypes were evaluated using the chi-square test, odds ratios (OR), and 95% confidence intervals (CI). Overall survivals and associations with the histological subtypes were evaluated using the Kaplan-Meier method and the log-rank test.
  
  
  
  The prevalences of BM, synchronous BM, and SREs were 28.2%, 70.4%, and 68.7%, respectively. Adenocarcinoma was the most common histological subtype (46.7%), and was significantly more frequent among patients with BM (58.3% vs. 42.1%; p=0.003; OR: 1.92; 95% CI: 1.29-2.97). Squamous cell was significantly less frequent among patients with BM (13.0% vs. 29.8%; p=0.0004; OR: 0.35; 95% CI: 0.19-0.64). The median survival time after the first BM diagnosis was 4 months, and there was no significant difference in the survival periods for the various histological subtypes.
  
  
  
  Adenocarcinoma and squamous cell were significantly associated with higher and lower risks of developing BM, respectively.
authors.affiliation: Trauma-Orthopaedics Service, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: marreis@bol.com.br.
authors.forename: Marcelo Bragança Dos Reis
authors.initials: MB
authors.lastname: Oliveira
authors.affiliation: Faculty of Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Thoracic Diseases Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Fernanda Carvalho de Queiroz
authors.initials: FC
authors.lastname: Mello
authors.affiliation: Thoracic Diseases Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Marcos Eduardo Machado
authors.initials: ME
authors.lastname: Paschoal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000473:pathology / Q000556:secondary*; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D012306:Risk; D013534:Survival
keywords: Bone metastasis; Histology; Lung cancer; SRE