Carcinogenicity studies are performe to assess the potential of a device material to incite the growth of malignant cells.  ISO describes carcinogenicity testing as the means “to determine the tumorigenic potential of devices, materials, and/or extracts to either a single or multiple exposures over a period of the total life-span of the test animal.” The circumstances under which such an investigation may be required and such testing should be considered for devices that will have permanent contact (equal to or greater than 30 days) with tissues.