Objectives To present extensions to the International Agency for Research on Cancer (IARC) Monographs process, providing examples of application of meta-data to identifying carcinogenic hazard identifications and research gaps, and the potential use for guiding cancer control efforts. Qualitative and quantitative approaches will be contrasted.

Method The IARC evaluation process typically employs summary level meta-data, in the form of systematic reviews, and pooled- and meta-analyses.

Results IARC has heavily relied on published occupational epidemiological studies to identify specific carcinogens in the workplace and to form a scientific basis for the protection of workers worldwide. The evaluations of carcinogenic risk are made by international working groups of independent scientists and are qualitative in nature. Meta-analyses prepared for IARC working groups can complement the qualitative process and have been crucial in several instances; for example, in identifying sufficient evidence for lung and bladder cancer in painters and limited evidence for increased risk of bladder cancer among dry cleaners exposed to tetrachloroethylene and among professional drivers (bus, taxi, truck) with high exposure to outdoor air pollution. Since IARC does not provide recommendations for regulation or legislation, meta-relative risks can also be used to calculate attributable fractions to guide cancer control efforts, for agents in which a causal association is assumed and exposure prevalence has been well-characterised.

Conclusions The IARC Monographs Programme is an authoritative source for the identification of carcinogenic hazards in the environment. Applying meta-analyses to the IARC process can be a useful tool for informing hazard identification and providing guidance for cancer control efforts.