Psychosocial working conditions and the risk of esophageal and gastric cardia cancers.

Abstract

For reasons yet unknown, the incidence of esophageal and gastric cardia adenocarcinoma is increasing rapidly and moderately, respectively. These tumors occur predominantly among males. We hypothesized that stressful psychosocial working conditions might be involved in the etiology of these cancers. To study if job strain, work pace satisfaction and coping are linked to the risk of esophageal or cardia cancers. A nationwide Swedish population-based case-control study including 189 and 262 esophageal and cardia adenocarcinoma cases, respectively, 167 esophageal squamous-cell carcinoma cases, and 820 controls. All study subjects were interviewed. The relative risk was estimated using odds ratios, with 95% confidence intervals, adjusted for potential confounders. We found no statistically significant associations between two different measures of job strain and the three cancer types, except between one job strain measure and risk of cardia adenocarcinoma (OR: 2.2; 95% CI: 1.0-4.8). There was a moderately strong association between having a covert coping style, compared to an overt, and risk of both esophageal (OR: 1.8; 95% CI: 1.2-2.8) and cardia adenocarcinoma (OR: 1.5; 95% CI: 1.0-2.3). Among subjects reporting low work pace satisfaction we found an almost 4-fold increased risk of esophageal squamous-cell carcinoma (OR: 3.8; 95% CI: 1.3-11.0), and a nearly 3-fold increased risk of esophageal adenocarcinoma (OR: 2.8; 95% CI: 1.1-7.0). Work-related stress does not seem to be of importance in the etiology of adenocarcinoma of the esophagus or the gastric cardia. However, the interaction of a stressful work environment and the individual's responses to it may be associated with a moderately increased risk of these cancer types.