【正文】 humans, and therefore the use of the model should be applicable to human risk assessment. ? The use of the model should supplement the 2year carcinogenicity study and it should provide additional information that is not readily available from the 2year study. ? Animal welfare, animal numbers, and overall economy of the carcinogenic evaluation process should be considered. Twoyear Carcinogenesis “Bioassay” Protocol Current Global Carcinogenicity Study Requirements Standard Tissue List Kidney Urinary bladder Aorta Heart Trachea Lungs Liver Gallbladder Pancreas Fat Salivary gland Spleen Cervical lymph node Mesenteric lymph node Thymus Tongue Esophagus Stomach Duodenum Jejunum Ileum Cecum Colon Mammary gland Skin Skeletal muscle Sciatic nerve Parathyroid Thyroid Adrenal gland Pituitary Prostate Seminal vesicles Testes Epididymides Ovaries Oviducts Uterine horns Uterine body Cervix Vagina Brain Spinal cord Sternum Rib/bone Eyes Harderian glands BM smear Nares Clitoral/preputial gland Zymbal ’ s gland Gross lesions 美國毒性病理學會（ STP）建議致癌試驗進行組織病理學檢查的最基本的受檢內(nèi)容目錄 Tumor Bearing Animals in Control Groups from Rodent Studies Source : J. K. Haseman (unpublished summary of . NTP data). Comparative Percent Incidence of Pertinent Neoplasia in Different Strains of Rats and Mice (104 Weeks Old) Note : F344, Fischer 244 rats。 S D, Sprague– Dawley rats。 B6C3F1, mice, (C57BL/6N+C3H/HeN)F1。 CD 1, 1CRCr: CD 1 mice。 NA, nonapplicable。 the average number used by species/strain/gender was in excess of 750 animals Preclinical approaches for assessing carcinogenic potential Tumorigenicity in humans, nonhuman primates and rodents Spontaneous tumor rates in the breeder and control animals The Neonatal Mouse Pietra et al. (1959). The neonatal mouse is one of the alternative in vivo models, for detecting the carcinogenic potential of pharmaceuticals. This is in agreement with the suggestions of ICH, which allows the use of one alternative study in place of one of the 2year carcinogenicity studies. When treatment begins within the first 24 hours of life, the study design is described as “newbornmouse”. “neonatal mouse” includes test item administration at different timepoints from birth to three weeks of age. Fujii (1991) reported that the neonatal mouse assay showed a sensitivity of 85% and a positive prediction rate of 96% pared to the results of the adult mouse 2year carcinogenicity study. Flammang et al. (1997) considered this model to have high sensitivity and specificity to detect genotoxic carcinogens as well as presenting advantages such as reduced test article requirements, decreased animal numbers and costs and a reduced pletion time. It does not respond to chemicals acting via epigeic mechanisms. McClain et al. (2022) reported that neonatal mice have been shown to have a reduced time for tumor induction, a higher multiplicity of induced tumors