Stress susceptibility, beta-blocker use and cancer survival

Sammanfattning: Accumulating evidence suggests that chronic stress may influence tumour biology through activation of neuroendocrine pathways and thus impair survival. However, measuring stressful exposures and their influence on health is challenging, partly due to substantial inter-individual variation in stress susceptibility. The thesis aimed to explore whether stress resilience and use of β-adrenergic receptor blockers, which are implicated in regulation of neuroendocrine stress response pathways, are linked to survival after a primary cancer diagnosis using data from Swedish national registers. In a cohort of male cancer patients born during 1952-1956 who had their stress resilience assessed during a mandatory conscription examination in late adolescence, low compared with high stress resilience was associated with a higher overall mortality rate. Statistically significant reductions in survival were observed among men with carcinomas of the oropharynx, prostate, upper respiratory tract, and Hodgkin’s lymphoma. In a cohort of patients diagnosed with pancreatic adenocarcinoma during 2006-2009, β-blocker users had a lower pancreatic cancer mortality rate than non-users, particularly among patients without distant metastases at diagnosis. In a cohort of patients diagnosed with non-small cell lung cancer during 2006-2014, there was no clear association between β-blocker use and lung cancer survival, but we cannot exclude the possibility of associations in some sub-groups defined by histology, stage and β-blocker types. In a cohort of patients diagnosed with hepatocellular carcinoma during 2006-2014, β-blocker use was associated with lower liver cancer mortality, particularly among patients with localised disease. A higher-magnitude inverse association was observed for non-selective β-blocker use. In conclusion, greater stress resilience and β-blocker use are associated with improved survival among patients with some cancer types, and this may be explained by a variety of pathways.