IARC group 2A

IARC Group 2A

The International Agency for Research on Cancer (IARC) is a specialized cancer agency of the World Health Organization (WHO). It is responsible for conducting and coordinating research into the causes of cancer. One of its key functions is to evaluate the carcinogenic risks of various substances to humans. The IARC classifies agents into different groups based on the strength of evidence regarding their carcinogenicity. This article focuses on IARC Group 2A, which includes agents that are "probably carcinogenic to humans."

Definition

IARC Group 2A is used to classify agents for which there is limited evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals. This classification implies that there is a credible link to cancer in humans, but the evidence is not conclusive. The classification is based on a comprehensive review of scientific studies and data by expert working groups.

Criteria for Classification

The classification into Group 2A is based on the following criteria:

• Limited evidence in humans: This means that a positive association has been observed between exposure to the agent and cancer, but other explanations for the observations (such as chance, bias, or confounding) could not be ruled out with reasonable confidence.
• Sufficient evidence in animals: This indicates that there is a causal relationship between the agent and cancer in experimental animals.
• Mechanistic and other relevant data: Additional data that support the classification, such as mechanistic studies, may also be considered.

Examples of Group 2A Agents

Some examples of agents classified as Group 2A include:

• Glyphosate: A widely used herbicide that has been classified as probably carcinogenic based on studies showing a positive association with non-Hodgkin lymphoma.
• Red meat: Consumption of red meat has been associated with colorectal cancer, leading to its classification in Group 2A.
• Shift work involving circadian disruption: This refers to work schedules that disrupt the body's natural circadian rhythm, which has been linked to an increased risk of cancer.

Implications of Classification

The classification of an agent as Group 2A has several implications:

• Public Health: It informs regulatory agencies and the public about potential cancer risks, guiding policy and preventive measures.
• Research: It highlights the need for further research to clarify the carcinogenic potential of the agent in humans.
• Regulation: It may lead to regulatory actions to limit exposure to the agent, depending on the level of risk and the availability of alternatives.

Also see

• IARC Group 1
• IARC Group 2B
• IARC Group 3
• Carcinogen
• Cancer prevention