Causes of death and metastatic patterns in Swedish cancer patients

Abstract: This thesis aimed to investigate possibilities to utilize death certificates in cancer epidemiology by analyzing nationwide databases from Sweden. Excessive information is available when investigating causes of death in cancer patients, including comorbidities and metastatic patterns. We used the Swedish Family- Cancer Database, which includes data from e.g. the Cause of Death Register and the Cancer Registry, in our analyses. Half of prostate and breast cancer patients die from other causes than the respective cancers. Cox regression models were applied, and prostate paper I and breast paper II cancer patients were found to be at an increased risk of death from various causes, e.g. heart failure, diseases of pulmonary circulation, and external causes, including suicide and falls. Additional information may be found in the multiple causes of death, which reveal that prostate cancer patients are at an increased risk to die from anemia and urinary system diseases. These findings can be explained by both cancer and treatment related mechanisms. Metastatic patterns in lung cancer were assessed: metastatic sites varied depending on the histological subtype, age, and gender paper III. Squamous cell lung cancer was less prone to metastasize than other histological subtypes. Adenocarcinoma tends to metastasize to the bone and within the respiratory system. Small cell lung cancer frequently metastasizes to the liver. Survival in metastatic lung cancer is worst in liver metastases, elderly, and men. Survival in metastatic cancer is better if the location of the primary tumor is known compared with if the primary location is unknown paper IV. There are some exceptions however, cancers of the pancreas, liver, and stomach. Metastases to the liver, irrespective whether the primary tumor is known or unknown are associated with a poor prognosis.