Oncology Expert Partly Allowed to Opine on Specific Causation

Plaintiff, Robert Mullenhour, as the personal representative of Richard Lee Mullenhour’s estate, brings this toxic tort action under the Federal Employers’ Liability Act (“FELA”), against his Decedent’s former railroad employers, APU Consolidated, Inc. (“APU”), Consolidated Rail Corporation (“Conrail”) and Norfolk Southern Railway Company (“NS”).

Plaintiff alleged that Defendants each negligently exposed Decedent, over the course of his railroad career, in a manner that resulted in his development of lung cancer, which led to his death.

Defendants sought to exclude the testimony of Plaintiff's expert Dr. Mark Levin. Plaintiff made a reciprocal motion to exclude the testimony of Defendants' expert Dr. Peter G. Shields.

Oncology Expert Witnesses

Dr. Mark Levin is a licensed, board-certified physician with specialties in Internal Medicine and Oncology, and he is eligible in Hematology. Over the course of his career, Levin has been involved in clinical research and patient treatment, and has served as Chief or Director of Hematology and Oncology divisions at four institutions, including a medical school. He has also developed clinical research programs at two institutions.

Want to know more about the challenges Mark Levin has faced? Get the full details with our Challenge Study report.

Dr. Peter Gary Shields has served as a tenured Professor in the Departments of Internal Medicine in the College of Medicine and the Department of Epidemiology at the College of Public Health at The Ohio State University. He also worked at Georgetown University, where he was the Deputy Director of the Lombardi Comprehensive Cancer Center.

Other positions that he has held in the past several years at Georgetown included Interim-Chair of the Department of Medicine, Chief of the Division of Cancer Genetics and Epidemiology in the Department of Oncology, Vice-Chair of the Department of Oncology and Associate Director for Cancer Control and Population Sciences.

Get the full story on challenges to Peter Shields' expert opinions and testimony with an in-depth Challenge Study.

Discussion by the Court

A. Defendants' Motion to Exclude

Plaintiff brought Levin to testify on both general and specific causation with regard to welding fume exposure. Defendants have moved to exclude Levin, arguing that his methodology is flawed. First, Defendants argued that Levin's process for researching and arriving at his general causation opinion on welding fume exposure was not reliable. Second, they objected to a portion of Levin's testimony on specific causation, arguing that he had no basis to claim that exposure to any welding fume levels "above background" could have contributed to Plaintiff's cancer. Third, they objected to the entirety of Levin's specific causation opinion on the basis that he used an unreliable source for his facts and data.

1. General Causation Opinion

Levin's general causation opinion heavily relies on work by the International Agency for Research on Cancer ("IARC"), which found that certain levels of exposures to welding fumes could increase the risk of lung cancer. Defendants did not object to any aspect or finding of this study or any of Plaintiff's other sources. Rather, they cited language from his deposition where he stated that his search process for articles that formed the basis of his opinion took "perhaps an hour or so." Defendants attempted to frame this as a critical flaw in Levin's methodology. That argument failed.

First, Defendants did not cite a single case suggesting that there is an abstract minimum threshold of time that an expert must spend developing his methodological framework. Nor is there one; the time an expert puts into the preparation of a report could vary widely between cases and depends on a variety of factors. That is why the standard for admissibility focuses on the substance of the report and testimony rather than arbitrary procedural factors such as how much time went into its preparation.

Indeed, this exact case shows why there is no such standard. First, Levin stated that there were a number of "articles I'm aware of, I know of because of previous cases" prior to beginning his search. Thus, Levin's search did not start from scratch, but was informed by previous work. Second, Levin's description of what took him "an hour or so" was not his reading of the literature, or his preparation of the report. Rather, it was the time to find relevant articles. Levin testified that the full process of generating his report took approximately a week. Defendants' focus on Levin's testimony asks the wrong question (how much time Levin put into the report is not dispositive under Rule 702) and gives the wrong answer (the total time was far more than an "hour or so.").

Ultimately, Defendants' argument confuses a secondary literature research process for a methodology. For example, Defendants argued that Levin did not provide a methodology for his "literature search." But the relevant methodology in this case is not a "literature search"—it is the actual analytical substance of Levin's opinions. Plaintiff provided ample citations for and explanation of the basis for Levin's opinions. Nor did Defendants even attempt to directly attack that substance.

2. "Any Level Above Background"

Next, Defendants argued that there is no methodological basis for Levin's assertion that any exposure to welding fumes "above background levels" would be sufficient to create a causal connection to Decedent's cancer.

Here, Defendants' motion stood on firmer ground. Defendants noted that in his deposition and report, Levin did not cite a single source or study claiming that any fume exposure above background would increase the likelihood of cancer. In fact, Plaintiff did not even try to defend this proposition but instead reframes Levin's statements, arguing that "in the proper context, Levin is not announcing that his causation threshold is 'any exposure above background."

Levin's initial statements regarding "the minimum above background level" (in the context of diesel fumes) were given in response to a question about what level of exhaust exposure "can cause lung cancer." Later, in response to a question about "what level of exposure to welding fumes is necessary for you to opine there's an increased risk of lung cancer," he stated that the answer would be "the same . . . as before, the minimum above background levels." This testimony is at best ambiguous, and it is at least plausible to interpret Levin as stating that he would be comfortable affirming specific causation if there was a measurement of any exposure above background levels.

Thus, assuming that Levin's statements can be read as affirming that there is a causal connection between cancer and exposure to welding fumes at any level "above background," the Court found that these statements are insufficiently supported by Levin's methodology and data under Rule 702. Levin is precluded from testifying to that effect.

3. Entirety of Levin's Specific Causation Opinion

Plaintiff argued that Levin's opinion on specific causation is primarily supported by his Rule 703 reliance on Dr. Paul Rosenfeld's report, which concluded that "to a reasonable degree of scientific certainty, that Mullenhour's welding-fume exposures were well above" the permissible limits.

Even though Levin can rely on another expert's data or analysis under Rule 703, that data must still be "reliable" for Levin's own expert opinion to be admissible under Rule 702.

Defendants argued that Rosenfeld's opinion is not reliable because he "conceded that his welding fume exposures estimates as to Decedent were based upon work Decedent never performed." But that misrepresents Rosenfeld's testimony. He indeed acknowledged that "most of the studies" he used were conducted in shops, even though the data was not always clear on that point because "everything is associated with a shop but sometimes the shops are outdoors." However, he emphasized that this data was the best available, noting that "very few studies, if any" were conducted outside. This does not show that Rosenfeld's methodology was unreliable, but only that he did the best work available with the data on hand.

Rosenfeld also explained why even indoor samples would be relevant for Mullenhour, describing how "we know that sometimes Mullenhour was put in positions where he might have been under a railcar or on the side of a railcar or . . . potentially inside a railcar where the wind would die down and he had the potential to be exposed to levels that are similar to those from the shop data."

Defendants also argued that Rosenfeld "admitted" that "actual testing of Decedent showed that welding fumes exposures were not above PELs [Permissible Exposure Limits]." However, Rosenfeld specifically addressed this discrepancy in his testimony, criticizing the relative accuracy and sufficiency of the "one or two selected incidents" which indicated that Mullenhour "was not exposed at levels that exceeded a PEL." Rosenfeld emphasized that these were merely "snapshots" from "[Decedent's] 38-year career" in which "it's more likely than not that he was in certain situations" that would cause "high levels of exposure to welding fumes." Rosenfeld even explained that there might have been incentive-based reasons for lack of monitoring inside railcars because industrial hygienists decided not to test based on the possibility of recording a PEL exceedance. Therefore, Rosenfeld sufficiently explained the basis for his methodology and the grounds for its reliability, specifically responding to Defendants' objections. Rosenfeld's report is reliable, and there is no independent basis to strike Levin's opinion for relying on it.

B. Plaintiff's Motion to Exclude

Plaintiff sought to exclude the testimony of Defendants' expert Dr. Peter G. Shields, M.D. First, Plaintiff argued that Shields is not qualified to assess Mullenhour's diesel exhaust or welding fume exposure. Second, Plaintiff argued that Shields' methodology is unreliable because "Shields does not state that he measured, calculated, or reconstructed Mullenhour's individual [exposures]."

1. Qualifications

Plaintiff argued that Shields is not qualified to testify because he "has no formal industrial hygiene training" and "is not a certified industrial hygienist." This argument confuses the relevant field of expertise. Industrial hygiene is the study of identifying best methods for measuring and quantifying exposure levels in the workplace. Shields, on the other hand, does not purport to have engaged in on-site quantitative testing, but instead relies on analysis already in the record. His work explores the effect of specific exposure levels on carcinogenic risk.

Plaintiff may be correct that portions of Shields' analysis also fall within the field of industrial hygiene. But there may often be overlap between separate fields of expertise. It is not enough to merely point to a separate field that also covers the relevant subject matter and argue that an opposing expert is not certified in that field.

Defendants provided substantial evidence that Shields is qualified to perform an assessment of cancer risk, and Plaintiff failed to rebut this by attacking his "industrial hygiene qualifications."

2. Methodology

Plaintiff argued that Shields used no case-specific information, and instead calculated Mullenhour's exposure and risk based on his general abstract conception of what would be "typical" for a railroad worker. If Plaintiff's portrayal of Shields' methodology was correct, this would certainly call it into question. The law is clear that any expert testifying on specific causation must integrate sufficient facts to connect the circumstances of the specific individual with the general literature. Yet Shields' reports made it clear that he tailored his analysis to Mullenhour's specific circumstances. Shields' reports showed that he reviewed testimony from Mullenhour, multiple co-worker witness testimony records, Mullenhour's medical records, Plaintiff's expert witness reports.

Nor did Shields perform a mere cursory acknowledgment of these records. Rather, he integrated a detailed analysis of Mullenhour's specific work environment into his report. Plaintiff cited Shields' statement that Mullenhour "was a carman who welded," claiming that his entire analysis was based on this conclusory and generalized description of Mullenhour's specific experiences and work. But that isolated quotation does not convey the full extent of Shields' discussion. Later on in the same paragraph, Shields goes into much more specific detail.

Plaintiff also cites to deposition testimony from an earlier case, where Shields stated that he had never performed an academic study that "focused on an individual only." Shields responded that it would be "nonsensical" to do this, because "that's not epidemiology . . . . that's the definition of a case report" with "no scientific method." Plaintiff argued that this testimony showed that Shields has never performed a particularized assessment of an individual. But Shields' testimony in that case made it clear he was discussing his academic work rather than his approach to providing expert testimony in a specific case. This testimony does not rebut Shields' showing that his methodology is reliable.

Held

• The Court denied Plaintiff's motion to exclude the testimony of Dr. Peter G. Shields.

• The Court granted in part and denied in part Defendants' motion to exclude the testimony of Dr. Mark Levin.

Key Takeaway

Fields of expertise can have significant overlap. Experts in industrial hygiene provide consultation advice to companies looking to improve and monitor the safety of work environments. Experts in oncology and epidemiology, on the other hand, study how specific types of exposures can lead to cancer and other diseases. These are not completely isolated fields of work. Both, for example, concern the relationship between exposure and disease—just applied to a different purpose.

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