Motor vehicle exposure and risk of oesophageal adenocarcinoma

The introduction of motor vehicles in industrialised countries during the mid 20th century seems to fit with the increasing incidence and the strong male predominance of oesophageal adenocarcinoma. The aim of the study was to test this new hypothesis in a large case-control study.

A nationwide, Swedish, population-based case-control study included 189 and 262 cases of oesophageal and cardia adenocarcinoma, respectively, 167 cases of oesophageal squamous-cell carcinoma and 820 frequency-matched controls during 1995-1997. Tumours were uniformly classified. Exposure data were collected at face-to-face interviews. Odds ratios (ORs), with 95% confidence intervals (CIs), were estimated and adjusted for confounding in multivariable logistic regression models.

There were no associations between regular contact with cars or airplanes regarding duration, frequency and age of contact and risk of oesophageal adenocarcinoma. The adjusted ORs for oesophageal adenocarcinoma, cardia adenocarcinoma and oesophageal squamous-cell carcinoma among persons spending at least two hours per day in cars were 1.3 (95%CI 0.7-2.3), 1.2 (95%CI 0.7-1.8), and 0.7 (95%CI 0.4-1.3), respectively. The corresponding ORs among frequent airplane passengers were 0.8 (95%CI 0.2-2.3), 1.1 (95%CI 0.5-2.2), and 0.9 (95%CI 0.3-2.5), respectively.

This large, population based case-control study does not support the hypothesis that frequent contact with motor vehicles has contributed to the increasing incidence or the male predominance of oesophageal adenocarcinoma.