Michael Crichton, a prolific writer, was known for his thoroughness and research in composing his novels (including Jurassic Park). He wrote in his 2003 Caltech Michelin Lecture:

“Let’s be clear: the work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world. In science, consensus is irrelevant. What is relevant is reproducible results. The greatest scientists in history are great precisely because they broke with the consensus.”

“There is no such thing as consensus science. If it’s consensus, it isn’t science. If it’s science, it isn’t consensus. Period.”

Unfortunately, scientific consensus is often the goal for courtrooms and regulatory purposes. Toxic tort attorneys look to various entities and experts for “consensus” about a relationship between various substances and cancer, in hopes they can use it later to sue deep-pocketed companies who sell products containing these substances.

One such entity is the International Agency for Research on Cancer (IARC). IARC is part of the World Health Organization and is well-known for classifying substances that it believes increase the risk for cancer. Because cancer creates fear in all of us, IARC’s work receives the highest attention around the world by governments, scientists, the media, and the public.

IARC assigns substances into one of four groups: carcinogenic in humans, probably carcinogenic, possibly carcinogenic, and indeterminate. These assignments are conducted in very strict confidence by Working Groups—scientists chosen by IARC and assembled several times a year to determine the carcinogenicity of one or more substances.

IARC then publicly announces the results, reached by consensus and often with no peer review, with statements in a scientific journal and in the media. It isn’t until several months later that a monograph is published sharing more details on the Working Group discussion and the studies used to reach its findings.

That delayed access to the Working Group deliberations and process allows the IARC’s initial public announcement of the findings to stand unchecked for a long while. Which is a problem, because IARC’s method for classifying substances has major flaws and conflicts of interest.

IARC misuses “hallmarks” in creating key characteristics of carcinogens (KCCs)

In 2000, Douglas Hanahan and Robert Weinberg published a paper called, “The Hallmarks of Cancer” in the journal Cell, with a follow-up paper 11 years later. They proposed that tumor development proceeds by a form of Darwinian evolution in which the acquired capabilities of cancer cells confer a selective advantage over normal cells.

Hanahan and Weinberg envisioned that these acquired capabilities of cancer cells could provide therapeutic targets. Their aspiration for these seminal papers was a conceptual framework built on science that would inform the diagnosis and treatment of cancer.

IARC uses the hallmarks in its classifications for carcinogenicity. However, we believe it does so inappropriately. Specifically, it misuses them to create its “key characteristics of carcinogens” (KCCs), providing leeway to use in-vitro data in its assignments of substances.

KCCs were created by several collaborators at IARC, along with Dr. Martyn Smith, a member of many IARC Working Groups (and founder of a council that profited from suing Starbucks under Prop. 65 in California). Together, they attempted to link Hanahan and Weinberg’s hallmarks to cellular effects of various substances, resulting in the KCCs. Their original paper was published in the journal, Environmental Health Perspectives.

The KCCs they designed enable IARC to use in-vitro data from EPA’s ToxCast and the National Institutes of Health Tox21 programs to modify the cancer classifications for substances from “possible” to “probable” with no attempt to ascertain the cancer mode of action for these chemicals. The result: IARC assignments using KCCs are no better than random chance.

In 2017, I (Ted) was co-author of a paper published in the journal, Regulatory Toxicology and Pharmacology. Itapplied a range of statistical methods to determine if IARC’s use of in-vitro data for its classifications was valid. What I and my co-authors discovered was that IARC’s methodology proved no better than a coin flip.

IARC Working Groups have many conflicts of interest

IARC states in the preamble to its monographs that members of its Working Groups are vetted for conflicts of interest. Nevertheless, it was quite easy to find several documented conflicts of interest for the scientists participating in the groups. Three of these are examined below.

  • A report in The Lancet, a renowned British medical journal, alleges that IARC downplayed risks of chrysotile asbestos in a tit-for-tat funding arrangement with the Russian Federation.
  • IARC’s assessment of benzene was criticized by a member of the Working Group, Dr. Peter Infante, for inconsistent selection of the studies used in a way to suggest that benzene had greater potency for causing cancer than the data indicated.
  • An investigation by Reuters obtained a draft of the IARC monograph linking glyphosate to Non-Hodgkin lymphoma which revealed obvious cherry-picking, including the removal of text stating that many scientists concluded no link between glyphosate and cancer.

A blatant and disingenuous conflict of interest occurred in this third example. The IARC Working Group for glyphosate met in March of 2015, after it was suggested by Dr. Chris Portier that the substance should be reviewed. Dr. Portier had worked for various U.S. public health agencies and served as an outside expert advising the glyphosate Working Group. Portier admitted in a later deposition that he started consulting for a law firm suing Monsanto two months before that Working Group meeting.

These examples of such behavior by IARC are not new. In the 1990s and early 2000s, IARC came under fire from its previous director, the head of the California EPA, and others, for maintaining secrecy about the ties of Working Group members to the plastics and rubber industries.

The claim by IARC that its monographs represent a “scientific consensus” from experts without conflicts of interest—aside from the problems with consensus outlined earlier by Crichton—is extremely misleading.

To be clear, in our view, the IARC monographs have never offered a consensus, merely a biased opinion by a select group of scientists. Yet, decision-makers worldwide depend on IARC to be a provider of quality information. Courtrooms accept IARC claims based on reputation alone. It’s time to take Michael Crichton’s words to heart and reframe the way we think about scientific consensus and the credibility of those who claim to have achieved it.

It is critical that IARC’s flawed process be greatly revised.