Work stress is unlikely to be an important risk factor in developing common cancers, a large, long-term study suggests.

Stress has been attributed to helping to trigger and maintain chronic inflammation and is associated with heart disease and depression. Work stress has also been suggested to increase the risk of cancer but few high-quality studies have checked into it.

Job stress is defined as having high demands and low control at work. (iStock)

After analyzing data from studies involving 116,000 participants aged 17 to 70 in six European countries, occupational health experts concluded work-related stress is "unlikely to be an important risk factor for colorectal, lung, breast or prostate cancers."

Investigators focused on participants' self reports of job strain — having high demands and low control at work. They analyzed data on hospital admissions, cancer cases and deaths from national cancer registries.

About five per cent of the participants, 5,765 out of 116,056, developed some form of cancer over the average 12 year followup.

Job strain was not associated with overall risk of cancer after adjusting for age, sex, socioeconomic position, body mass index, smoking and alcohol intake, Katriina Heikkilä of the Finnish Institute of Occupational Health and co-authors said in Thursday's issue of the British Medical Journal.

The data analysis did show an association between job strain and increased risk of coronary heart disease.

"Reducing work stress would undoubtedly improve the psychological and physical well-being 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 authors said.

The research was funded by the Finnish Work Environment Fund, Swedish Research Council for Working Life and Social Research, Danish National Research Centre for the Working Environment, BUPA Foundation and the Economic and Social Research Council, U.K.