|Rat Target Sites||Mouse Target Sites||TD50 (mg/kg/day)|
Key to the Table Above
The Carcinogenic Potency Database (CPDB) is a unique and widely used international resource of the results of 6540 chronic, long-term animal cancer tests on 1547 chemicals. The CPDB provides easy access to the bioassay literature, with qualitative and quantitative analyses of both positive and negative experiments that have been published over the past 50 years in the general literature through 2001 and by the National Cancer Institute/National Toxicology Program through 2004. The CPDB standardizes the diverse literature of cancer bioassays that vary widely in protocol, histopathological examination and nomenclature, and in the published author’s choices of what information to provide in their papers. Results are reported in the CPDB for tests in rats, mice, hamsters, dogs, and nonhuman primates.
For each experiment, information is included on species, strain, and sex of test animal; features of experimental protocol such as route of administration, duration of dosing, dose level(s) in mg/kg body weight/day, and duration of experiment; experimental results are provided on target organ, tumor type, and tumor incidence; carcinogenic potency (TD50) and its statistical significance; shape of the dose-response, author’s opinion as to carcinogenicity, and literature citation.
Only tests with dosing for at least ¼ the standard lifespan of the species and experiment length at least ½ the lifespan are included in the CPDB. Only routes of administration with whole body exposure are included. Doses are standardized, average dose rates in mg/kg/day. A description of methods used in the CPDB to standardize the diverse literature of animal cancer tests is presented for: 1) Criteria for inclusion of experiments 2) Standardization of average daily dose levels and 3) TD50 estimation for a standard lifespan. See Methods for other details.
TD50 provides a standardized quantitative measure that can be used for comparisons and analyses of many issues in carcinogenesis. The range of TD50 values across chemicals that are rodent carcinogens is more than 100 million-fold. More than half the chemicals tested are positive in at least one experiment.
A plot of all results on each experiment in the CPDB for this chemical is presented below. These results are the source information for the Cancer Test Summary table above.
Chemical (Synonym) CAS # Species Sex Strain Route Xpo+Xpt PaperNum 0 Dose 1 Dose 2 Dose 3 Dose Literature Reference or NCI/NTP:Site Path Site Path Notes TD50 DR Pval AuOp LoConf UpConf Cntrl 1 Inc 2 Inc 3 Inc Brkly Code
2-METHYLIMIDAZOLE 693-98-1 3972 M f b6c eat 24m24 TR516 : 0 81.3mg 163.mg 325.mg liv hpa 1.38gm * P<.04 p 589.mg n.s.s. 3/50 4/49 6/49 10/50 TBA MXB 729.mg Z P<.3 201.mg n.s.s. 23/50 49/49 33/49 39/50 liv MXB 1.62gm * P<.08 626.mg n.s.s. 4/50 4/49 6/49 10/50 liv:hpa,hpb,hpc. lun MXB no dre P=1. 3.12gm n.s.s. 4/50 4/49 0/49 1/50 lun:a/a,a/c. 3973 M m b6c eat 24m24 TR516 : 0 75.0mg 150.mg 325.mg liv hpc 378.mg Z P<.007 186.mg 6.01gm 4/50 8/50 14/50 (6/50) S MXB MXB 378.mg * P<.004 189.mg 3.41gm 10/50 22/50 22/50 27/50 liv:hpa,hpc; thy:fca. P thy fca 1.81gm * P<.002 p 819.mg 7.08gm 0/50 1/50 0/50 7/50 liv MXA 546.mg * P<.04 p 231.mg n.s.s. 10/50 22/50 22/50 22/50 liv:hpa,hpc. liv hpa 648.mg * P<.02 289.mg n.s.s. 7/50 14/50 13/50 18/50 S TBA MXB 866.mg Z P<.5 180.mg n.s.s. 50/50 34/50 50/50 46/50 liv MXB 546.mg * P<.04 231.mg n.s.s. 10/50 22/50 22/50 22/50 liv:hpa,hpb,hpc. lun MXB no dre P=1. 863.mg n.s.s. 14/50 9/50 10/50 9/50 lun:a/a,a/c. 3974 R f f34 eat 24m24 TR516 : 0 50.0mg 125.mg 250.mg thy MXA 882.mg * P<.0005 c 437.mg 3.20gm 1/50 1/50 1/50 11/50 thy:fca,fcc. thy fcc 1.38gm * P<.01 c 580.mg 149.gm 1/50 1/50 1/50 7/50 thy fca 2.10gm * P<.004 c 793.mg 13.8gm 0/50 0/50 0/50 5/50 liv hpa 2.00gm * P<.05 e 707.mg n.s.s. 1/50 0/50 2/50 4/50 TBA MXB 131.mg Z P<.2 47.5mg n.s.s. 48/50 45/50 49/50 (38/50) liv MXB 2.00gm * P<.05 707.mg n.s.s. 1/50 0/50 2/50 4/50 liv:hpa,hpb,hpc. 3975 R m f34 eat 24m24 TR516 : 0 12.0mg 40.0mg 120.mg ski MXA 624.mg * P<.04 233.mg n.s.s. 2/50 2/50 2/50 7/50 ski:bcc,ker,tri. S liv MXA 663.mg * P<.06 e 258.mg n.s.s. 0/50 1/50 3/50 3/50 liv:hpa,hpc. thy MXA 854.mg * P<.07 p 279.mg n.s.s. 1/50 2/50 1/50 5/50 thy:fca,fcc. pni isa 1.01gm * P<.02 350.mg n.s.s. 0/50 0/50 1/50 3/50 S TBA MXB 303.mg * P<.5 65.4mg n.s.s. 41/50 45/50 44/50 46/50 liv MXB 663.mg * P<.06 258.mg n.s.s. 0/50 1/50 3/50 3/50 liv:hpa,hpb,hpc.
See full CPDB Summary Table on 1547 chemicals. See Full CPDB for all results on 6540 experiments of 1547 chemicals.
A complete list of CPDB chemicals, which is searchable by name or by CAS number, is available here.
For a compendium of CPDB results organized by target organ, which lists all chemicals in each species that induced tumors in each of 35 organs, see Summary Table by Target Organ.
The CPDB is available in several formats that permit printing and downloading into spreadsheets and statistical databases.
A Supplementary Dataset gives details on dosing and survival for each experiment.
Relatively precise estimates of the lower confidence limit on the TD10 (LTD10) are readily calculated from the TD50 and its lower confidence limit, which are reported in the CPDB. For researchers and regulatory agencies interested in LTD10 values, we provide them in an Excel spreadsheet.
PDF versions of our publications of analyses using the CPDB are available, organized by year and by research topic.