What is a Daubert hearing?

A Daubert hearing is designed to allow courts to screen expert witnesses and prevent “junk science” from entering proceedings. In the Johnson & Johnson Daubert hearing, the opinion admitted experts with different interpretations of similar data. 

Judge Wolfson kept the door open for new information stating:

“Because of talc’s alleged carcinogenic properties, studies continue to be conducted by the scientific community. . . if supplemental reports impact my Daubert decisions made in this Opinion, I may amend my rulings at a later time.”

— Judge Freda L. Wolfson

Witnesses for the Plaintiffs

Judge Wolfson’s justification for admitting the expert testimonies of Dr. Ghassan Saed, Dr. William Longo, and Drs. Anne McTiernan, Daniel Clarkeson, and Arch Carson, composed 110 pages of her opinion. 

Drs. Longo and Saed completed studies or analyses while Drs. McTiernan, Clarkeson, and Carson conducted comprehensive epidemiological studies of available research. 

The first expert examined in Judge Wolfson’s opinion was Dr. Ghassan Saed. Dr. Saed is an expert in inflammation and oxidative stress and his lab “studies the effect of oxidative stress, inflammation in the causation of diseases, especially cancer.” Dr. Saed conducted lab study as part of his expert testimony. 

Dr. Saed’s experiment exposed in vitro, immortalized ovarian tissue to talc in solution in order to test whether talc could inflame ovarian tissue and lead to cancer. Using the results of his experiment, Dr. Saed testified that talc did inflame ovarian tissue and created an environment of oxidative stress, which could lead to ovarian cancer.

Because his study was conducted in an artificial environment, the court ruled that his experiment cannot prove a causal relationship. Furthermore, Dr. Saed could not measure ovarian cells that transformed into cancer cells as a result of talc exposure. The rest of Saed’s testimony was preserved.

Dr. William Longo, who was introduced as a materials science expert, has a Ph.D. in materials science and engineering. He worked in the U.S. Environmental Protection Agency in the peer review group for asbestos engineering. He helped craft the American Society for Testing of Materials (“ASTM”) protocols for testing asbestos materials with a transmission electron microscope (TEM).

In the TEM tests, Dr. Longo found “a total of 50 positive containers . . . out of 72 tested that gave an overall 69% positive result for the . . . containers and Imerys’ railroad car samples” from the 1960s until the 2000s. Dr. Longo was not allowed to testify that women were more likely than not to be exposed to airborne amphibole asbestos and asbestiform talc.

The defense representation frequently raised a variety of issues without evidence. In the testimony of Dr. Saed, the defense rebutted the replicability of Dr. Saed’s experiment but couldn’t explain why. 

Similarly, the defense argued that it was inappropriate for Dr. Longo to use the methodology recommended by the EPA Asbestos Hazard Emergency Response Act, but provided no suggestion for an alternative methodology. Judge Wolfson condemns these actions as having no merit or as a difference of opinion.

The final section addressing plaintiff witnesses combined the epidemiological studies of Dr. Anne McTiernan, Dr. Daniel Clarke-Pearson and Dr. Arch Carson. These experts were brought to prove through their research that talc causes ovarian cancer.

Dr. McTiernan possesses a Ph.D. in epidemiology as well as a medical degree and works at the Fred Hutchison Cancer Research Center in Seattle, Washington conducting epidemiologic research identifying risk factors for breast and ovarian cancer in women, and studies “prevention methods to reduce population and other markers of cancer risk.”

Dr. Clarke-Pearson possesses a Medical Doctorate (M.D.) and completed a residency in obstetrics/gynecology as well as a fellowship in oncology. Dr. Clarke-Pearson was also a faculty member of Duke University and has published approximately 250 peer-reviewed publications, the majority being “in the field of gynecologic oncology, and some have dealt with ovarian cancer, in particular, clinical trials describing advances in the treatment of ovarian cancer.”

Dr. Carson is an associate professor at the University of Texas School of Public Health and the Program Director of the Occupational and Environmental Medicine Residency training program at the University of Texas Health Center with an M.D. and a Ph.D. in toxicology. 

All of these doctors have completed a type of analysis known as a Bradford Hill Analysis, which is the benchmark for determining a medical causal relationship. The Bradford Hill Analysis consists of nine factors that together can create a causal relationship:

  1. Temporal relationship 
  2. Strength of association 
  3. Dose-response relationship
  4. Replication 
  5. Biological plausibility
  6. Consideration of alternative explanations
  7. Cessation of exposure
  8. Specificity of the association
  9. Consistency with other knowledge

In a review of the available epidemiologic studies, including 28 case control studies, three cohort studies, three meta-analyses, and one pooled analysis, all three experts stated that they believed that all of these criteria were sufficiently met.

Through the Bradford Hill Analysis, the experts concluded the risk of ovarian cancer among users of talcum powder is 22-31% higher than those who never used those products. Judge Wolfson agreed with the experts’ methods, stating “I find that the opinions of the general causation experts with respect to this factor are admissible. . . . Defendants have not presented any compelling grounds for the Court to find otherwise.”

The Defendants did not “challenge the experts’ basis for this conclusion,” that talc exposure increased ovarian cancer risk by 20-60% “and in fact, do not suggest that the experts’ calculation of relative risk, based on the aggregate studies, was not reliably reached.”

The defendants also did not argue that talc irritation didn’t cause cancer. Judge Wolfson wrote, “Importantly, Defendants do not dispute the known fact about the link of cellular inflammation to cancers in general.”

Key Witnesses for the Plaintiffs

  • Dr. Ghassan Saed
  • Dr. William Longo
  • Dr. Anne McTiernan
  • Dr. Daniel Clarke-Pearson
  • Dr. Arch Carson

Witnesses for the Defendants

Judge Wolfson spent 22 pages analyzing defense experts. The opinion stated: 

“Unlike, for example, Drs. Longo and Saed, Defendants’ experts, for the most part did not conduct their own individual testing, . . . Instead, Defendants’ experts rebut the opinions offered by Plaintiffs’ experts.”

The first defense expert examined was Dr. Gregory Diette. Dr. Diette was called to rebut the plaintiff’s Bradford Hill Analyses. The plaintiffs asserted, “Dr. Diette is not qualified to provide an epidemiological opinion as to the relationship between talc use and ovarian cancer, because the primary focus of his research is pulmonary disease.” Judge Wolfson denied the plaintiff’s motion to dismiss.

The second defense expert brought by Johnson & Johnson was Dr. Cheryl Saenz, an oncologist and gynecologist who claimed to have expertise in refuting the causal nature of the talc-ovarian cancer link. Dr. Saenz “considered certain of the Bradford Hill criteria in rendering her opinion” rather than conducting a full Bradford Hill analysis.  Despite the plaintiffs complaining of her insufficient research to critique their experts’ Bradford Analyses, Dr. Saenz was permitted.

The final defense expert was Dr. Benjamin Neel. Dr. Neel was criticized for opining on the safety of talc despite not having knowledge of talc’s “constituent components,” or the risks posed by contaminants. The defense responded that Dr. Neel only intended to rebut the reliability of Dr. Saed’s study and his testimony was allowed. 

The second accusation levied at Dr. Neel was that he was “not qualified to testify ‘regarding the strengths and weaknesses of the epidemiological studies,’ nor is he qualified to conduct a Bradford Hill analysis, as he did here.” Judge Wolfson ruled that Dr. Neel’s possession of an M.D. allowed him to conduct his analysis and his testimony was allowed.

Key Witnesses for the Defense

  • Dr. Gregory Diette
  • Dr. Cherly Saez
  • Dr. Benjamin Neel

What's Next?

With the Daubert hearing concluded, the plaintiffs and defendants have received the rules regarding their experts and the testimony they may provide. From this point, both sides will now prepare for either settlement negotiations or, if those fail, trial. 

The mountainous claims that plaintiffs brought “junk science” that has long dogged talc litigation has been summited. In its place is a new clifface: the admitted testimony will argue causation in front of juries. 

Although the Daubert hearing has allowed the experts to testify, a vital hurdle to overcome, the hearing does not establish an assumption of correctness for those experts.

For plaintiffs, this victory is only in gaining a foot in the door that may prove Johnson & Johnson acted with negligence. Many talc plaintiffs who previously had their cases and monetary recovery reversed due to the “unreliability” of expert witnesses claiming causation may also be able to appeal.

Fundamentally, this Daubert hearing has set a new precedent for how courts admit experts claiming talcum powder can cause ovarian cancer.