title: Metastatic sites and survival in lung cancer.
abstract: OBJECTIVE
  Population-based data on metastatic sites and survival in site-specific metastases are lacking for lung cancer and for any cancer because most cancer registries do not record metastases. This study uses a novel population-based approach to identify metastases from both death certificates and national inpatient data to describe metastatic pathways in lung cancer patients.
  
  
  METHODS
  17,431 deceased lung cancer patients diagnosed 2002-2010 were identified from the nationwide Swedish Cancer Registry, which is based on compulsory reports. The influence of age at diagnosis, sex, and histological subtype on metastatic spread was investigated. Survival in metastatic lung cancer was assessed by histology and metastatic site.
  
  
  RESULTS
  The most frequent metastatic sites were the nervous system, bone, liver, respiratory system, and adrenal gland. Liver (35%) and nervous system (47%) metastases were common in patients with metastases from small cell lung cancer, and bone (39%) and respiratory system (22%) metastases in adenocarcinoma. Women (43% vs. 35%) and younger patients had more metastases to the nervous system. Median survival after diagnosis was 13 months for non-metastatic and five months for metastatic lung cancer. In this novel data, liver metastases conferred the worst prognosis (three months), especially for large cell histology. Bone metastases also featured poor survival, whereas survival in respiratory and nervous system metastases was better.
  
  
  CONCLUSIONS
  Metastatic sites and survival in metastatic lung cancer is influenced by sex, histological subtype, and age at diagnosis. Liver and bone metastases signal poor survival, compared with nervous system metastases.
authors.affiliation: Division of Molecular Genetic Epidemiology, German Cancer Research Centre (DKFZ), 69120 Heidelberg, Germany; Center for Primary Health Care Research, Lund University, Malmö, Sweden. Electronic address: matias.riihimaki@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Riihimäki
authors.affiliation: Cancer Gene Therapy Group, Transplantation Laboratory & Haartman Institute, University of Helsinki, 00290 Helsinki, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Hemminki
authors.affiliation: Division of Molecular Genetic Epidemiology, German Cancer Research Centre (DKFZ), 69120 Heidelberg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Fallah
authors.affiliation: Division of Molecular Genetic Epidemiology, German Cancer Research Centre (DKFZ), 69120 Heidelberg, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Thomsen
authors.affiliation: Center for Primary Health Care Research, Lund University, Malmö, Sweden; Stanford Prevention Research Center, Stanford University School of Medicine, CA, USA.
authors.forename: K
authors.initials: K
authors.lastname: Sundquist
authors.affiliation: Center for Primary Health Care Research, Lund University, Malmö, Sweden; Stanford Prevention Research Center, Stanford University School of Medicine, CA, USA.
authors.forename: J
authors.initials: J
authors.lastname: Sundquist
authors.affiliation: Division of Molecular Genetic Epidemiology, German Cancer Research Centre (DKFZ), 69120 Heidelberg, Germany; Center for Primary Health Care Research, Lund University, Malmö, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Hemminki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology / Q000401:mortality* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D012042:Registries; D013548:Sweden / Q000453:epidemiology
keywords: Bone metastasis; Brain metastasis; Liver metastasis; Lung metastasis