Work-related stress not a cancer hazard

While a commonly perceived cause of cancer, stress does not appear to contribute to an increased risk of developing cancer, a study has found.

The study used data from Swedish national registries and included 56,146 male and 56,911 female participants in the Västerbotten Intervention Programme. Researchers used the well-established Karasek job demand/control model to assess prediagnostic work-related stress in relation to cancer risk.

The mean age of the cohort at baseline was 46 years, with 20 percent of men and 22 percent of women being current smokers. The median body mass index was 26 kg/m² for men and 24 kg/m² for women. Over a median follow-up of 16 years, 11,971 individuals received a cancer diagnosis (6,280 men, 5,691 women), with the cumulative cancer incidence at age 80 years estimated to be 38 percent for men and 28 percent for women.

Multivariable Cox proportional hazards regression analysis showed that compared with “low-strain” work (low demand/high control), “high-strain” work (high demand/low control) did not confer an increased risk of cancer. This was true for both men (hazard ratio [HR], 1.01, 95 percent confidence interval [CI], 0.94–1.08) and women (HR, 0.99, 95 percent CI, 0.92–1.07).

Risk estimates were also null for most cancer types assessed, including prostate, breast, colorectal, lung, and gastrointestinal (GI).

The risk of GI cancer was lower with “passive” (low demand/low control) vs “low-strain” work, specifically for colorectal cancer in women (HR, 0.71, 95 percent CI, 0.55–0.91), although statistical significance was lost after further adjustments.

The findings do not support a role for work-related stress in determining cancer risk. This helps fill an important knowledge gap, given the common concern about stress being a risk factor for cancer.