Experts Discuss Roundup Cancer Link at Monsanto Science Week

Monsanto Science Week marked the first time that the science behind the company’s Roundup weed killer was scrutinized under oath. Expert witnesses from both sides, including epidemiologists, toxicologists and others analyzed relevant research in open court before U.S. District Court Judge Vince Chhabria in what is formally known as a Daubert hearing.

Daubert hearing is an evaluation to determine the admissibility of testimony from expert witnesses. Legal teams for the plaintiffs and the defendants present their experts to educate the court on the science behind both sides of the Roundup cancer connection.

Judge Chhabria presides over hundreds of Roundup cancer lawsuits in California’s Northern District. California State Court Judge Ioana Petrou, who is presiding over the California state court cases consolidated before her in Alameda County. They will decide whether there is evidence to support the plaintiffs’ claim that exposure to Monsanto’s Roundup weed killer can cause non-Hodgkin’s lymphoma.

What is Monsanto Science Week and How Does it Affect Roundup Cancer Lawsuits?

Michael L. Baum is managing partner of Baum, Hedlund, Aristei & Goldman, a law firm representing over 600 individuals in state and federal claims against Monsanto. He explained Science Week below:

“We are presenting the experts who are going to be testifying about the general causation issue – whether or not Roundup causes non-Hodgkin’s lymphoma. The experts from both sides are presented to the judges so they can evaluate whether the experts used a valid methodology for arriving at their conclusions. If they determine that the experts used a valid methodology to arrive at their conclusions, then they are permitted to testify in front of juries.”

Experts for the Plaintiffs (in order of appearance):

Experts for Monsanto (in order of appearance):

Transcripts from Monsanto Science Week

Dr. Beate Ritz (pages 9-167)

Dr. Dennis Weisenburger (pages 168-213)

Dr. Dennis Weisenburger (pages 218-286)

Dr. Alfred Neugut (pages 287-370)

Dr. Alfred Neugut (pages 377-401)

Dr. Charles “Bill” Jameson (pages 402-539)

Dr. Christopher Portier (pages 540-595)

For More Highlights of Science Week Check Out Carey Gillam’s Live Blog at U.S. Right to Know

Testimony from Dr. Beate Ritz

In her Expert Report, Dr. Ritz concluded that “to a reasonable degree of scientific certainty, glyphosate causes NHL (non-Hodgkin lymphoma). Furthermore, to a reasonable degree of scientific certainty, glyphosate based formulations, including Roundup, cause NHL.”

Dr. Ritz’s testimony began with questions from plaintiffs’ attorney Katherine Forgie. Ritz walked through a series of epidemiological studies that show statistically significant risk factors linking glyphosate to cancer. Based on the literature, Dr. Ritz testified that the risk to individuals considered “routine users” of glyphosate was significant.

Judge Chhabria questioned Dr. Ritz on numerous facets of the literature. He appeared to be concerned about whether the studies were adjusted for exposure to other pesticides.

Dr. Ritz was also asked about a study Monsanto cites as critical evidence that there is no link between glyphosate and NHL. In her testimony, Dr. Ritz explained that the Agricultural Health Study (AHS) had several short-comings.

According to Dr. Ritz, the AHS data on glyphosate relied heavily on memories of individuals who filled out questionnaires to assess usage. “Recall error” is “really the enemy of exposure assessment,” Dr. Ritz said.

“I have to downgrade the importance of the AHS study for time exposure…I can’t take this study seriously if it shows no effect because all the effects are drowned in the noise of exposure misclassification.” – Dr. Beate Ritz

Midway through the day, Dr. Ritz gave a discussion of meta-analyses in which she testified that while there is animal data, “more importantly” human data shows an association between glyphosate and lymphoma. “DNA strand breaks have been shown to occur when individuals are exposed,” she said.

In an interesting exchange, Judge Chhabria asked Dr. Ritz if she believed glyphosate causes NHL or is capable of causing NHL. She answered by saying it depends on the individual’s case.

Dr. Ritz concluded her testimony after about five hours. Before leaving the witness chair, Judge Chhabria asked her one poignant question:

When asked if the studies she evaluated show that glyphosate has caused NHL in people, her reply: “Yes, I think they do.”

Testimony of Dr. Dennis Weisenburger

Dr. Dennis Weisenburger is the Chair of the Pathology Department of the City of Hope Medical Center in Omaha, Nebraska. He specializes in the study of non-Hodgkin’s lymphoma.

In the early part of his testimony, Dr. Weisenburger discussed why he believes that research studies provide strong evidence that exposure to glyphosate and glyphosate-based herbicides like Roundup can cause people to develop NHL. When questioned by Judge Chhabria about whether glyphosate is capable of causing NHL in humans at current exposure levels, Dr. Weisenburger answered, “I believe that, yes.”

“I concluded with a reasonable degree of medical certainty that glyphosate and the formulations including Roundup can cause non-Hodgkin’s lymphoma in humans exposed to these chemicals, both in the workplace and probably in the environment.” – Dr. Dennis Weisenburger

Testimony of Dr. Alfred Neugut

Dr. Alfred Neugut is a practicing medical oncologist, professor of cancer research and professor of medicine and epidemiology at Columbia University.
Dr. Neugut began his testimony by saying research shows a connection between glyphosate and NHL with great specificity. The consistency in study findings is something that cannot be ignored, he said, as scientists have seen repeated evidence linking glyphosate to NHL. “Every time you look what comes up? Glyphosate and NHL,” said Dr. Neugut.

In a discussion about the AHS study, Dr. Neugut called it an “excellent study for many things.” However, when it comes to understanding the link between glyphosate exposure and NHL, he testified that the AHS “fails.”

Among some of the study’s shortcomings, Dr. Neugut said the AHS does not account for the boom in glyphosate use in the 1990s, which dramatically altered the exposure levels for farmers compared to the beginning of the study when baseline exposure levels were established. Another flaw he cited was the loss to follow-up among study participants. AHS researchers attempted to avoid having large amounts of missing exposure data by using imputation—predicting or ‘guestimating’ exposures for participants who did not follow-up.

“You have an error on top of an error on top of an error… the AHS study is basically not so useful,” – Dr. Alfred Neugut

Testimony of Dr. Charles “Bill” Jameson

Dr. Charles W. Jameson (who goes by “Bill”) was the first toxicology expert to take the witness stand. Dr. Jameson has served as program leader for the National Toxicology Program (NTP) at the NIH’s National Institute of Environmental Health Sciences for 12 years. He was also a member of the International Agency for Research on Cancer (IARC) Working Group that concluded glyphosate is a probable human carcinogen in March 2015.

Dr. Jameson detailed the body of research that led him to conclude that glyphosate and Roundup can cause NHL at real-world exposure levels that farmers, farm workers and a host of others face when spraying the herbicide.

His testimony brought objections from Monsanto’s legal team, which Judge Chhabria overruled. Judge Chhabria questioned Dr. Jameson about the conclusions of the IARC Working Group. In particular, he asked why the Working Group arrived at the conclusions for “limited” evidence of carcinogenicity in humans and “sufficient” evidence of carcinogenicity in animals.

In his explanation, Dr. Jameson recalled that some of the scientists in the Working Group felt that the evidence for carcinogenicity in humans was actually stronger than the “limited” conclusion. Others disagreed, however.

In a rare moment of levity in an otherwise tense day of testimony, Dr. Jameson joked, “…if there are three epidemiologists in a room and you ask them their opinions, you’ll get four opinions.”

Like the other expert witnesses for the plaintiffs, Dr. Jameson said the weight of the combined animal and human data is what demonstrates the carcinogenicity of glyphosate and Roundup.

With regard to the animal studies, Dr. Jameson testified that it is “extraordinary” that so many have been conducted to evaluate a chemical, as the cost of such studies can be very expensive. The fact that researchers have so many animal studies for glyphosate adds to the strength of his conclusion that glyphosate causes cancer, he said. He also noted that animal studies demonstrate replication of several tumor sites, including liver tumors and malignant lymphoma.

For example: “…we had a lot of replication for malignant lymphomas in the mouse,” Dr. Jameson said, adding that the same tumors were seen in different studies in different labs at different times, which further underscores the strength of conclusion for carcinogenicity.

During cross examination, Judge Chhabria admonished a Monsanto attorney for repeatedly questioning Dr. Jameson on his deposition rather than questioning the expert on his opinions.

“Why don’t you ask his about his opinion now, Judge Chhabria told Monsanto attorney Joe Hollingsworth. “That’s normally how we do it”

When Hollingsworth asked again about some comments he made in his deposition, Dr. Jameson replied, “I’ve been misquoted and things have been taken out of context so many times… ”

Indeed, context was an area of emphasis for Judge Chhabria, who appeared to grow concerned about the possibility that Monsanto might be taking expert statements out of context. This was underscored when Judge Chhabria ordered Monsanto’s attorney to read aloud into the record two pages of testimony from a deposition that supported the expertise of Dr. Jameson’s analysis before he would allow the attorney to introduce a separate example from a deposition that sought to undercut Jameson’s expertise.

In toxicology, I evaluated all of the available toxicology data I could find, and it showed that glyphosate is an animal carcinogen, and that is the premise that is widely accepted in the toxicology — the scientific community, that if something is shown to be an animal carcinogen, then it is probably also a human carcinogen; and it’s biologically plausible that it is…a human carcinogen. – Dr. Charles Jameson

By | 2018-03-14T12:44:46+00:00 March 8th, 2018|Blog, Monsanto Roundup News, Michael L. Baum|