An expert witness for the defense in a trial to determine if Monsanto's weed killer Roundup caused the cancers of three plaintiffs told a courtroom on Monday and Tuesday it’s much more likely the cancer was caused by simple bad luck rather than exposure to a pesticide.
“What proportion of cancer mutations across all cancer types are in your view attributable to natural copy (cell division) errors?” asked defense attorney Manuel Cachan.
“About two-thirds,” Cristian Tomasetti responded.
“What are your opinions on non-Hodgkin’s lymphoma?”
“The R factor (random cancer not Roundup), are in 96% (of cases).”
However, attorneys for the three plaintiffs sought to establish that external factors and environment (including Roundup) were more important in causing cancers than Tomasetti’s testimony claimed.
The trial in the 21st Missouri Judicial District court is being streamed live courtesy of Courtroom View Network.
The suit filed by plaintiffs Marty Cox, Cheryl Davis and Gary Gentile asks for damages for medical bills, treatments, physical pain and mental anguish. The three have different forms of Non-Hodgkin’s Lymphoma (NHL), a cancer. Cox was diagnosed with B-cell lymphoma, Gentile with high-grade-B-cell lymphoma and Davis with follicular lymphoma. The plaintiffs are in their 60s and 70s.
Glyphosate is the active ingredient in Roundup.
Attorneys for both sides during the run of the trial have used selective studies to back their positions. Attorneys for the three plaintiffs have referred to a determination made in 2015 by the International Agency for Research on Cancer (IARC), that glyphosate is a probable carcinogen for animals and humans based on evidence and testing.
Attorneys defending Monsanto cited a judgment by the Environmental Protection Agency (EPA), that there was no risk when the product was used properly. In addition, a 2018 (Andreotti) report, part of an Agricultural Health Study, an ongoing study of genetics, lifestyle and AG factors and how they impact the farming industry, decided there was no link between glyphosate and malignancies.
Tomasetti, an applied mathematician in oncology - the understanding of how cancer happens - said random cell mutations in humans happens as a normal bodily function. Their numbers are impacted by a person’s age, more so in aging, from hereditary or inherited family factors, or the R-factor, random cell replication.
“The cells are dividing, replicating, playing a large role in causing cancer,” Tomasetti said. “The older we get the higher the (cancer) risk.”
Tomassetti said he received $900 per hour for his expert witness work for Monsanto. The company has paid him $290,000 for his work over the past two years.
“What is the hereditary risk for NHL?” Cachan asked.
“It’s extremely small, .5% (of cases),” Tomassetti said.
“Environmental?”
“About 3.5%, or something like that.”
Tomassetti said cells with mutations typically die or repair themselves.
“If a cell determines that its DNA is too damaged, the cell will decide to do the equivalent of committing suicide, kill itself, die in order to protect the rest of the cells,” he said. “It’s very common in our bodies. It’s a good event.”
“Would that lead to cancer?” Cachan asked.
“Impossible, the cell is gone.”
“Where do most cell mutations come from?”
“From normal cell division,” Tomassetti said.
“Do all of these mutations lead to cancer?”
“No.”
Tomassetti said a “driver cell mutation” can lead to cancer if a mutation doesn’t die and there is no cell repair. The damaged cell replicates. It becomes dangerous, an unlucky mutation (a one in 10,000) event.
Tomassetti added that environmental causes account for less than 5% of cases and that obesity in a person can be a cause. Earlier in the trial under questioning, Davis was asked if she had been obese. She said she had been only on the “low end” of obese.
During cross examination, plaintiff attorney Gibbs Henderson asked Tomassetti if he was an expert on NHL.
“It depends on what you mean,” Tomassetti said.
Henderson exhibited earlier deposition testimony in which Tomassetti said he was not an expert on the disease.
“You don’t know all the chemicals and environmental exposures that cause cancer, there are some where environment played a significant role,” Henderson said.
“Yes,” Tomassetti answered.
“You said that 3.9% were from environmental factors. But it’s approximately 9%, correct?”
“The number of cases is different from the number of mutations, yes,” Tomassetti agreed. “It’s about 8%, (NHL cases caused by external factors).”
“You said in June (deposition) that NHL was not caused by excess body weight, you’re not a physician,” Henderson said.
“Correct,” Tomassetti responded.
“You’ve never written a response to a doctor on the cause of a cancer.”
“No.”
“Chemicals can promote cancers, yes?” Henderson asked.
“Yes.”
“A chemical can cause a (cell) replication to speed up.”
Tomassetti agreed.
“Environment can be one of the causes.”
“I think I made that clear,” Tomassetti said.
Henderson exhibited a 2017 document from Tomassetti which read that cancers could be due to environmental factors, "most of which have not been discovered.”
“You agree that IARC is a reputable agency?” Henderson asked.
“Yes,” Tomassetti said.