Higher levels of psychological distress may be associated with an increased risk of death from certain cancers, found a meta-analysis by the universities of Edinburgh, Sydney and University College London.
The findings are observational, so no firm conclusions about cause and effect can be drawn. However, the authors say their findings add to the growing evidence that psychological distress could have some predictive capacity for certain physical conditions.
There is some evidence that psychological distress (anxiety and depression) is related to increased rates of cardiovascular disease, but links with different types of cancer are either unclear or untested. So a team of researchers from University College London, University of Edinburgh, and University of Sydney set out to examine if psychological distress is a potential predictor of site specific cancer mortality.
They analysed data from 16 studies (13 from England and three from Scotland), which started between 1994 and 2008. In total, 163,363 men and women aged 16 or over and free from cancer at the start of the study, were included.
Psychological distress scores were measured using the general health questionnaire and participants were monitored for an average of nine and a half years. During this time, there were 4,353 deaths from cancer.
Several factors that could have influenced the results were taken into account, including age, sex, education, socioeconomic status, BMI, smoking and alcohol intake.
Dr David Batty from University College London, the lead author, said: “After statistical control for these factors, the results show that compared with people in the least distressed group, death rates in the most distressed group were consistently higher for cancer of the bowel, prostate, pancreas, and oesophagus and for leukaemia.”
The authors point out that this association may also be affected by reverse causality, where undiagnosed (early) cancer might have had an underlying impact on mood.
In a bid to correct for this, they carried out a further analysis excluding study participants who died in the first five years of follow-up, but this made no difference to the findings -the links between distress and cancer remained.
Batty said: “Our findings contribute to the evidence that poor mental health might have some predictive capacity for certain physical diseases but we are a long way off from knowing if these relationships are truly causal.”
Abstract
Objective: To examine the role of psychological distress (anxiety and depression) as a potential predictor of site specific cancer mortality.
Design: Pooling of individual participant data from 16 prospective cohort studies initiated 1994-2008.
Setting: Nationally representative samples drawn from the health survey for England (13 studies) and the Scottish health survey (three studies).
Participants: 163 363 men and women aged 16 or older at study induction, who were initially free of a cancer diagnosis, provided self reported psychological distress scores (based on the general health questionnaire, GHQ-12) and consented to health record linkage.
Main outcome measure: Vital status records used to ascertain death from 16 site specific malignancies; the three Scottish studies also had information on cancer registration (incidence).
Results: The studies collectively contributed an average of 9.5 years of mortality surveillance during which there were 16 267 deaths (4353 from cancer). After adjustment for age, sex, education, socioeconomic status, body mass index (BMI), and smoking and alcohol intake, and with reverse causality (by left censoring) and missing data (by imputation) taken into account, relative to people in the least distressed group (GHQ-12 score 0-6), death rates in the most distressed group (score 7-12) were consistently raised for cancer of all sites combined (multivariable adjusted hazard ratio 1.32, 95% confidence interval 1.18 to 1.48) and cancers not related to smoking (1.45, 1.23 to 1.71), as well as carcinoma of the colorectum (1.84, 1.21 to 2.78), prostate (2.42, 1.29 to 4.54), pancreas (2.76, 1.47 to 5.19), oesophagus (2.59, 1.34 to 5.00), and for leukaemia (3.86, 1.42 to 10.5). Stepwise associations across the full range of distress scores were observed for colorectal and prostate cancer.
Conclusion: This study contributes to the growing evidence that psychological distress might have some predictive capacity for selected cancer presentations, in addition to other somatic diseases.
Authors
G David Batty, Tom C Russ, Marjorie MacBeath, Emmanuel Stamatakis, Mika Kivimäki
[link url="http://www.bmj.com/company/wp-content/uploads/2017/01/anxiety-depression-cancer.pdf"]BMJ material[/link]
[link url="http://www.bmj.com/content/356/bmj.j108"]BMJ abstract[/link]