International Agency for Research on Cancer

The International Agency for Research on Cancer (IARC; French: CIRC) is an intergovernmental agency forming part of the World Health Organisation of the United Nations.

Its main offices are in Lyon, France. Its role is to conduct and coordinate research into the causes of cancer. It also collects and publishes surveillance data regarding the occurrence of cancer worldwide. It maintains a series of monographs on the carcinogenic risks to humans posed by a variety of agents, mixtures and exposures. Following its inception, IARC received numerous requests for lists of known and suspected human carcinogens. In 1970, the IARC Advisory Committee recommended that expert groups prepare a compendium on carcinogenic chemicals, and it began publishing its monographs series with this aim in mind.

IARC categories

The IARC categorizes agents, mixtures and exposures into five categories.

• Group 1: carcinogenic to humans.
• Group 2A: probably carcinogenic to humans.
• Group 2B: possibly carcinogenic to humans.
• Group 3: not classifiable as to carcinogenicity in humans.
• Group 4: probably not carcinogenic to humans. Only one substance â€" caprolactam â€" has both been assessed for carcinogenicity by the IARC and placed in this category.

Industry influence and transparency

Critics of the IARC have stated that it has become susceptible to industry influence and suffers from a lack of transparency. Lorenzo Tomatis, its director from 1982 to 1993, was "barred from entering the building" in 2003 after "accusing the IARC of softpedaling the risks of industrial chemicals" in a 2002 article. In 2003 thirty public-health scientists signed a letter targeting conflicts of interest and the lack of transparency. The IARC rejected these criticisms, and there was hope that the controversy would "die down" after Paul Kleihues (Director from 1994) retired in 2004 and Peter Boyle became the new director, followed by Christopher Wild since 2009.

Tomatis focused on the IARC monographs which rate chemical's carcinogenicity, and cited several cases in his 2002 critique. In 1998 a panel voted 17-13 to rate 1,3-butadiene a carcinogen. A second vote which Tomatis called "highly irregular" occurred after "industry observers schmoozed with the panelists and one panelist left the meeting", and a 15-14 vote downgraded the chemical to a "possible carcinogen". Joan Denton, director of California's Office of Environmental Health Hazard Assessment, made accusations in relation to styrene in 2002, and Michael Jacobsen of the Center for Science in the Public Interest criticized the inclusion of industry observers in a saccharin panel, who were allowed to vote. Tomatis has also highlighted DEHP. In defense of the IARC, Kleihues noted that only 17 of 410 of the working-group participants were consultants to industry and these people never served as chairs. He said that "people who receive funds from affected agencies do not vote", and further noted that industry-funded scientists are important because industry often funds studies.

IARC's secrecy led a Lancet Oncology editorial to warn of the agency's eroding reputation. As of 2003 the IARC did not release details of disputed votes, did not release the financial disclosure forms required of panelists, or the names of the panelists until the panel is complete. Individuals being considered for the new director are released only to representatives from the 16 member countries. Kleihues and other agency officials defend the IARC, with Kleihues noting that procedures and names are listed on the finished monographs, and said names are not released to avoid political pressures. The IARC was considering new transparency disclosures such as a "narrative" explaining disputed votes.