medwireNews: Work-related stress is unlikely to be a major cause of cancer, say researchers who found no link between job strain and the risk for overall or site-specific malignancy.
The meta-analysis, published in the BMJ, combined data from 12 European cohort studies for 116,056 men and women aged 17 to 70 years who completed the Job Content Questionnaire (JCQ) and Demand-Control Questionnaire.
In all, 5765 incident cancers were reported for participants over a median 12 years of follow up, including 522 cases of colorectal cancer, 374 lung cancers, 1010 breast cancers, and 865 prostate cancers.
In multivariate analysis, high psychosocial strain, defined as a job with high demands and low control, did not significantly predict overall cancer risk, after adjusting for age, gender, socioeconomic status, body mass index, and smoking and alcohol habits.
Nor was there any link between high job strain and the likelihood of developing site-specific cancers of the lung, breast, prostate, or colon and rectum, report Katriina Heikkilä (Finnish Institute of Occupational Health, Helsinki) and co-authors.
"Though reducing work stress would undoubtedly improve the psychological and physical wellbeing of the working individuals as well as the working population, it is unlikely to have an important impact on cancer burden at a population level," the researchers comment.
The meta-analysis was unable to exclude residual confounding from the impact of shift work on diet or exposure to harmful chemicals, such as pesticides or solvents, during working hours. But the team believes this is unlikely to have hidden a strong link between job strain and cancer risk.
"We did not investigate the possible influence of non-work related stress or its co-occurrence with work stress in our meta-analyses, but future studies would do well to examine whether these have an effect on risk," Heikkilä et al add.
"It is also possible that work related psychosocial stress could be related to the risk of some other cancers."
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