Occupational asbestos exposure and digestive cancers - a cohort study

Although the role of asbestos in the genesis of mesothelioma and primary bronchopulmonary cancers has been established, results from studies focusing on the relationship between occupational exposure to asbestos and digestive cancer remain contradictory.

To determine whether occupational asbestos exposure increases the incidence of digestive cancers.

Our study was a retrospective morbidity study based on 2024 subjects occupationally exposed to asbestos. The incidence of digestive cancer was calculated from 1st January 1978 to 31st December 2004 and compared with levels among the local general population using Standardized Incidence Ratios. Asbestos exposure was assessed using the company's job exposure matrix.

Eighty-five cases of digestive cancer were observed within our cohort, for an expected number of 66.90 (SIR = 1.27 [1.01; 1.57]). A significantly elevated incidence, particularly notable among women, was observed for peritoneal mesothelioma, independently of exposure levels. A significantly elevated incidence was also noted among men for cancer of small intestine and oesophagus, for cumulative exposure indexes for asbestos above 80 fibres/mL x years. A significantly elevated incidence of cancer of the small intestine was also observed among men having been exposed to asbestos for periods in excess of 25 years and for mean exposure levels in excess of 4 fibres/mL.

This study suggests the existence of a relationship between exposure to asbestos and cancer of the small intestine and of the oesophagus in men.