Toxicology expert witness advises on a case happened in South Dakota involving a diabetes sufferer who claims the drug caused bladder cancer. Plaintiff filed a product liability action against the defendant manufacturer of a Type II diabetes drug alleging she developed bladder cancer from the drug. The plaintiff alleges that the defendants concealed and continue to conceal their knowledge of the drug’s unreasonably dangerous risks from plaintiff, his physicians, other consumers and the medical community. The defendants failed to adequately inform consumers and the prescribing medical community about the risk of bladder cancer associated with the drug’s use.
Question(s) For Expert Witness
Is the drug at issue capable of causing bladder cancer in humans because it causes bladder tumors in rats?
Expert Witness Response
There is insufficient evidence to conclude that the pharmaceutical causes bladder cancer in humans based upon findings in rats. Cancer will afflict 40% of all people in their lifetime. Bladder cancer is the fifth most common cancer. Cancer is caused by lifestyle, spontaneous alterations in genetic material and other endogenous processes rather than other exogenous factors.
The use of animal tests cannot be used to determine causation in humans without sufficient evidence in studies in humans, because the cancer mechanism in experimental animals may not be relevant for human cancer. Chemicals, including pharmaceuticals, that are known human bladder carcinogens are genotoxic and have been shown to cause cancer through genotoxic mechanisms, whereas studies of this pharmaceutical do not show that it is genotoxic.
Studies of this pharmaceutical in experimental animals have identified some increases in bladder tumors but the likely mechanism involves indirect toxic effects mediated by the formation of crystals in the urine causing tumor promotion. These crystals would not be expected to occur in humans due to differences in the urine biochemistry between rats and humans. Consequently, the findings of bladder tumors in rodents are not predictive of the development bladder cancer in humans.
The expert relied on his experience as a toxicologist, researcher and physician, published scientific and toxicology literature on this pharmaceutical and similar drugs.
The expert is a physician, biochemist and certified toxicologist with more than 40 years of toxicology research. He has authored peer-reviewed articles on carcinogenicity, tumor promotion, cancer mechanism, and DNA changes associated with chemical exposure.
About the author
Kristin Casler
Kristin Casler is a seasoned legal writer and journalist with an extensive background in litigation news coverage. For 17 years, she served as the editor for LexisNexis Mealey’s litigation news monitor, a role that positioned her at the forefront of reporting on pivotal legal developments. Her expertise includes covering cases related to the Supreme Court's expert admissibility ruling in Daubert v. Merrell Dow Pharmaceuticals Inc., a critical area in both civil and criminal litigation concerning the challenges of 'junk science' testimony.
Kristin's work primarily involves reporting on a diverse range of legal subjects, with particular emphasis on cases in asbestos litigation, insurance, personal injury, antitrust, mortgage lending, and testimony issues in conviction cases. Her contributions as a journalist have been instrumental in providing in-depth, informed analysis on the evolving landscape of these complex legal areas. Her ability to dissect and communicate intricate legal proceedings and rulings makes her a valuable resource in the legal journalism field.
