A Thorough Explanation Of The ‘Cancer Presumption’

Many states have enacted laws that create a presumption that a public safety officer’s cancer (among other things) is presumed to be caused by the job. In a case involving the widow of Littleton, Colorado firefighter Jeffrey Christ, who succumbed to brain cancer, the Colorado Court of Appeals explained at length the rationale behind “presumptive causation” statutes.

The Court began by examining traditional workers’ compensation law on whether an illness or injury is caused by the job: “In a traumatic injury case, causation is usually a simple matter. But causation is not simple when the employee claims that he developed a disease through an exposure to a toxic substance. In that case, employees usually try to prove general causation through two types of evidence. First, they offer toxicological evidence, which is usually based on in vitro experiments and animal studies. Second, they offer testimony based on epidemiological studies. Courts regard epidemiology as the best evidence of general causation.”

The Court then turned to how these standards of proof have applied to public safety employees: “Consider now a firefighter who believes that his disease was caused by an exposure to a toxic substance that he encountered while battling fires. How will he fare under the traditional model?

“The answer is ‘badly.’ And it is easy to see why. First, the firefighter may have no way of identifying the substances to which he was actually exposed. Rarely is monitoring equipment installed at a fire scene before the firefighters arrive. Consequently, he may be unable to locate the relevant epidemiological studies, if indeed those exist. Second, even if the firefighter can show that he was exposed to a substance that is known to cause his type of disease, he may lack the kind of information needed to prove specific causation.”

It was for this reason, the Court found, that the Colorado Legislature adopted a presumption that a firefighter’s cancer is presumed to be caused by the job. Under the Colorado law, a firefighter can rely on the statute if he meets the following conditions: (1) He has worked as a firefighter for at least five years; (2) he suffers from one of the listed forms of cancer; and (3) after becoming a firefighter, he underwent a physical exam that revealed no evidence of his current disease.

If those conditions are met, specific causation is presumed. The firefighter’s cancer is considered an occupational disease that resulted directly from employment. The presumption of causation is not irrebuttable, and it may be overcome by a preponderance of the medical evidence.

The Court explained that the presumption was a broad one: “First, it contemplates a wide range of potential exposures. The statute presumes that the pertinent type of cancer can be caused by an exposure to some unspecified substance or intangible agent (such as radiation). It presumes that the claimant was exposed to such substances or agents while working as a firefighter. And it presumes that those exposures caused the firefighter’s particular cancer.

“Second, it contemplates a wide range of biological mechanisms. The statute presumes that the unspecified exposure caused the firefighter’s cancer directly, or in combination with other genetic or environmental factors. It presumes that the exposure either caused a disease that would not otherwise have occurred, or hastened the onset of a disease that the firefighter would have developed later.

“The statute places a formidable burden on the firefighter’s employer. The difficulty lies not in the degree of proof required (which, as noted, is merely a preponderance of the evidence), but in the breadth of the presumption, the nature of the facts presumed, and its practical effect under traditional toxic tort principles. The Legislature considered whether firefighting exposures can cause certain cancers. And it responded with a statute that presumes causation. That statute reflects a valid policy choice, and an employer gains nothing by challenging the wisdom or the evidentiary foundation of the legislature’s decision.”

Applying these principles, the Court concluded that the City had not overcome the presumption that Christ’s cancer was caused by the job. The Court held that “the City produced no evidence about Christ’s workplace exposures. In the absence of evidence about Christ’s specific exposures, the City relied on general causation evidence. The City suggested, in effect, that firefighting exposures could not have caused the cancer because such exposures cannot cause any form of brain cancer. But that effort fell short.

“The City’s evidence supports a reasonable inference that claimant’s brain cancer was not caused by any of the carcinogens commonly associated with firefighting. But the City presented no evidence to support an inference that Christ’s workplace exposures were limited to that group of substances. In the absence of such evidence, a fact finder could only speculate that the exposures were so limited. And speculation is insufficient to rebut a substantive presumption that Christ, while acting as a firefighter, was exposed to a substance or agent that caused his particular cancer.

“It would similarly be unreasonable to infer that no substance can cause brain cancer. The administrative law judge in this case found ‘no known or putative carcinogen has been definitely associated with brain tumor development in either humans or animals.’ However, in light of the limits of existing scientific knowledge (limits acknowledged by the City’s experts), it would be farfetched to further conclude, from the absence of evidence showing a definite link, that no such link exists. The absence of medical evidence linking a known carcinogen with a particular form of cancer simply represents a void of information, and cannot be considered proof a reasonable link does not exist.”

City of Littleton v. Industrial Claim Appeals Office of State, 2012 WL 5360912 (Colo. App. 2012).