Metastatic sites and survival in lung cancer.
OBJECTIVES
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.


MATERIALS AND 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.


CONCLUSION
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.
['Riihimäki|M|M|', 'Hemminki|A|A|', 'Fallah|M|M|', 'Thomsen|H|H|', 'Sundquist|K|K|', 'Sundquist|J|J|', 'Hemminki|K|K|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D005260:Female D006801:Humans D008175:Lung Neoplasms D008297:Male D008875:Middle Aged D009362:Neoplasm Metastasis D009367:Neoplasm Staging D012042:Registries D013548:Sweden
Bone metastasis Brain metastasis Liver metastasis Lung metastasis