Carcinogenicity studies are preclinical studies that are conducted to evaluate the potential of a substance to cause cancer. These studies are typically conducted in laboratory animals, such as rats or mice, to assess the safety of a drug or other substance before testing in humans.

The primary objective of carcinogenicity studies is to identify any potential carcinogenic effects of the substance and to evaluate the potential mechanisms of carcinogenicity. These studies can include a range of endpoints, such as tumor incidence, tumor type, and latency period.

Carcinogenicity studies are typically conducted over a period of 18 to 24 months, during which the animals are exposed to the test substance in their diet or by other routes of administration. The animals are closely monitored for any signs of toxicity and are sacrificed at the end of the study period for a detailed examination of the tissues and organs, including the incidence and type of any tumors that developed.

Carcinogenicity studies are usually conducted in two species of animals, typically rodents, to help evaluate the relevance of the findings to humans. The results of carcinogenicity studies can help identify any potential carcinogenic effects of the substance, and can help inform decisions about the safety of the substance for use in humans.

It is important to note that not all substances that induce tumors in laboratory animals will necessarily cause cancer in humans, and vice versa. Therefore, the results of carcinogenicity studies should be interpreted in conjunction with other preclinical and clinical data, as well as other relevant factors, such as exposure levels and duration, to help inform decisions about the safety of the substance for use in humans.