burning building in Quebec
Photo by Sylvain Pedneault
New research suggests that prolonged exposure to work-related stress may increase a man’s risk of several cancers.
The study showed a significant association between work-related stress lasting 15 years or more and non-Hodgkin lymphoma (NHL) as well as lung, colon, rectal, and stomach cancers.
Men who had worked as firefighters, engineers, mechanics, and repair workers were most likely to report work-related stress.
Marie-Élise Parent, PhD, of Institut national de la recherche scientifique (INRS) in Laval, Quebec, Canada, and her colleagues conducted this research and published
the results in Preventive Medicine.
The researchers studied 3103 men with 11 different types of cancer who were diagnosed from 1979 to 1985. The team compared these men to 512 control subjects from the general population.
Both cases and controls were interviewed and asked to describe each job they had during their lifetime, including the occurrence of stress related to a job and the reason for that stress.
The researchers then calculated odds ratios (OR) for the association between perceived workplace stress and its duration, and each cancer site. The analyses were adjusted for lifestyle and occupational factors.
The team found that having at least one stressful job in a lifetime was associated with increased odds of 5 cancers:
- Lung—OR=1.33
- Colon—OR=1.51
- Bladder—OR=1.37
- Rectal—OR=1.52
- Stomach—OR=1.53.
When the researchers looked at the duration of stress, they found no significant association between any of the cancers and work-related stress lasting less than 15 years.
However, there were significant associations for several cancers and work-related stress lasting 15 to 30 years or more than 30 years. These included:
- NHL—15-30 years, OR=1.47; >30 years, OR=1.69 (P=0.02)
- Lung cancer—15-30 years, OR=1.47; >30 years, OR=1.51 (P=0.01)
- Colon cancer—15-30 years, OR=1.32; >30 years, OR=1.64 (P<0.01)
- Rectal cancer—15-30 years, OR=1.84; >30 years, OR=1.48 (P=0.01)
- Stomach cancer—15-30 years, OR=2.15; >30 years, OR=1.48 (P=0.01).
The occupations with the highest prevalence of work-related stress were firefighter (40% of firefighting jobs reported as stressful), industrial and aerospace engineer (31%), and motor vehicle and rail transport mechanic/repair worker (28%).
For the same individual, stress varied depending on the job held.
The study also showed that perceived stress was not limited to high work load and time constraints. Customer service, sales commissions, responsibilities, having an anxious temperament, job insecurity, financial problems, challenging or dangerous work conditions, employee supervision, interpersonal conflict, and a difficult commute were all sources of stress listed by study participants.
The researchers said one of the biggest flaws in previous studies of this kind is that none of them assessed work-related stress over a full working lifetime. The team said this made it impossible to determine how the duration of exposure to work-related stress affects cancer development.
This study, on the other hand, shows the importance of measuring stress at different points in an individual’s working life, the researchers said. They added that their results raise the question of whether chronic psychological stress should be viewed as a public health issue.
However, the team also pointed out that these results are unsubstantiated because they are based on a summary assessment of work-related stress for a given job. There is a need for epidemiological studies based on reliable stress measurements, repeated over time, and that take all sources of stress into account.
