Can Asbestos Exposure Cause Colon Cancer?

While the medical and scientific communities are not in total agreement as to whether asbestos exposure directly causes colon cancer, there is much evidence to suggest that there is some relationship between the two.

Scientific Research on Asbestos and Colon Cancer

One study found that individuals with high-grade exposure to asbestos were twice as likely to contract the disease; however, the majority of research on the topic does not substantiate so high an increase in colon cancer risk as a result of asbestos exposure.  Another study on cement workers (including asbestos cement workers) found increased incidence of cancer in the right portion of the colon, and that cancer distribution was noticeably different than that in other blue-collar workers.  A population-level study conducted in Montreal found an increased risk of colon cancer among asbestos-exposed workers, findings that were reiterated in a Stockholm population-based study, as well as by a study conducted in the Netherlands.

There is, however, disagreement within the scientific community as to the causal relationship between asbestos exposure and colon cancer.  A meta-analysis of existing research in 1994 suggested a possible association between asbestos and colon cancer, however the study authors qualified that these results may be skewed because of misdiagnosis of the type of cancer or a tendency to misclassify the cause of death in asbestos-exposed subjects.  Another weight of evidence meta-study concluded there simply wasn’t enough evidence to support the claim that asbestos exposure causes colon cancer in humans, and that animal testing in laboratory settings showed no such relationship.

The consensus within the scientific community on the connection between asbestos exposure and colon cancer seems to be that there is insufficient evidence to conclude a causal relationship, and that more research is needed.  However, there are many studies of particular populations that find higher rates of colon cancer among asbestos-exposed populations, suggesting a possible link.

Legal Opinions

This disagreement within the research community is reflected in the legal record, as judges and workers’ compensation boards have been inconsistent in their rulings in cases hinging on the connection between asbestos and colon cancer.  To date, cases have been decided based on the facts of individual cases, and the courts have deferred establishing a strong precedent on the matter.