Highlights of Noteworthy Decisions

Decision 105 19
L. Gehrke - R. Ouellette - K. Hoskin
  • Board Directives and Guidelines (cancer) (gastrointestinal)
  • Cancer (esophagus)
  • Exposure (asbestos)

The worker was an underground mechanic in uranium, gold, and nickel mines from 1972 until 2007. He was diagnosed with gastroesophageal junction adenocarcinoma in October 2007 and passed away in December 2007. The worker's estate appealed a decision of the Appeals Resolution Office denying entitlement to survivors' benefits. In the first interim decision, Decision No. 105/19I, the panel found that the worker had a smoking history of 34-pack years and that his father, who worked in a uranium mine, was diagnosed with prostate cancer. The panel also made findings on the worker's employment history and requested a report of an occupational hygiene expert on the worker's exposures. Based on that report, the panel made findings regarding the worker's occupational exposures and requested the assistance of a Tribunal Medical Assessor in Decision No. 105/19I2.

The appeal was allowed.
The worker had entitlement under the Board's policy on gastrointestinal cancer (Operational Policy Manual, Document No. 16-02-11). Gastroesophageal junction cancer falls within the classification of gastro-intestinal cancers in the policy, as it is located at the junction of the esophagus and stomach. Both gastric and esophageal cancers are within the classification of gastro-intestinal cancer as described in the policy.
The policy provides that claims are favourably considered if there is a clear and adequate history of occupational exposure to asbestos dust of a continuous and repetitive nature that represents or is a manifestation of the major component of the occupational activity.
The interpretation of the policy was addressed in a 2009 ODPRB research paper that was discussed in Decision No. 144/12. That paper states that the policy intended that regular significant exposure to asbestos would provide sufficient exposure to explain the development of gastro-intestinal cancers; "clear and adequate" was intended to refer to known asbestos exposure and not exposure that is hypothetical or speculative; "continuous" refers to ongoing exposure and not a brief exposure such as a period of six months; "repetitive" describes the frequency of exposure, which should be daily or three to five times per week; and consistent with the continuous and repetitive nature of the exposure, the asbestos exposure must be a major component of the occupational activity.
The evidence established that the worker had a clear and adequate history of exposure to asbestos that represented a major component of the worker's work activity. The worker was exposed to asbestos dust on a daily basis from 1972 to 1979 for approximately 9 to 20 hours per week. As he was diagnosed 35 years after his first exposure, the 20 year latency period in the policy was also met.
The Tribunal's Medical Assessor noted that the association between gastroesophageal junction cancer and asbestos is uncertain based on the current medical literature. He concluded that it was not possible to rule out the contribution of occupational exposures, but that the evidence for non-occupational risk factors of smoking and obesity was much stronger and it was more likely that these played a causative role.
However, medical certainty was not the test for causation. Rather, the test was whether, on a balance of probabilities, the worker's exposure to asbestos was a significant contributing factor in his cancer.
The Board policy, which was developed based upon expert medical advice, considers entitlement for all gastro-intestinal cancers where the exposure criteria are met, and states that the site of the gastro-intestinal cancer is not taken into account when determining entitlement. The policy takes into account the potential for scientific uncertainty and provides a structure for making decisions about whether asbestos exposure was a significant contributing factor in a particular case. The policy is also silent on the role of non-compensable factors.
While the non-compensable factors of smoking and obesity may have been significant contributing factors, the worker's exposure to asbestos was also a significant contributing factor and met the criteria for entitlement under Board policy.