PMID- 16728370
OWN - NLM
STAT- MEDLINE
DCOM- 20060628
LR  - 20161124
IS  - 1528-7394 (Print)
IS  - 0098-4108 (Linking)
VI  - 69
IP  - 10
DP  - 2006 May
TI  - Relative cancer potencies of selected dioxin-like compounds on a body-burden 
      basis: comparison to current toxic equivalency factors (TEFs).
PG  - 907-17
AB  - Recent National Toxicology Program (NTP) cancer bioassay data for 
      2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran 
      (4-PeCDF), 3,3',4,4',5-pentachlorobiphenyl (PCB 126), and a mixture of these 
      three compounds offer opportunities to assess the accuracy of current World 
      Health Organization (WHO) 1998 toxic equivalency factors (TEFs) for these 
      compounds under a variety of assumptions. An evaluation of the current TEF values 
      for these compounds using body burden in nanograms per kilogram as the dose 
      metric is presented. Average lifetime body burdens were estimated for all 
      compounds at all dose groups based on measured tissue concentrations at 4 time 
      points during the 2-yr NTP studies. Poly-3 adjusted tumor incidences for 
      hepatocellular adenomas, cholangiocarcinomas, and the two tumors combined were 
      modeled using a quantal multistage model and the Hill model with lifetime average 
      body burden as the dose metric. Benchmark doses for a 10% response (BMD10) for 
      each compound and the mixture were estimated. With TCDD as the reference 
      standard, relative potency (REP) estimates were derived from ratios of the BMD10 
      estimates for PCB 126, 4-PeCDF, and for the toxic equivalent (TEQ) mixture. On a 
      body-burden basis, PCB 126 and 4-PeCDF were 2- to 3-fold and 10- to 12-fold less 
      potent than predicted based on the WHO TEFs, respectively, while the TEQ mixture 
      was approximately 3- to 5-fold less potent than predicted by the TEFs. The 
      current WHO TEF values, which were derived from data on noncancer endpoints 
      evaluated on an administered dose basis, overpredict the carcinogenic potency of 
      these compounds on a body-burden basis compared to TCDD.
FAU - Gray, Michael N
AU  - Gray MN
AD  - AMEC Earth & Environmental, Inc., Portland, Maine, USA.
FAU - Aylward, Lesa L
AU  - Aylward LL
FAU - Keenan, Russell E
AU  - Keenan RE
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - J Toxicol Environ Health A
JT  - Journal of toxicology and environmental health. Part A
JID - 100960995
RN  - 0 (Benzofurans)
RN  - 0 (Polychlorinated Dibenzodioxins)
RN  - DFC2HB4I0K (Polychlorinated Biphenyls)
RN  - TSH69IA9XF (3,4,5,3',4'-pentachlorobiphenyl)
RN  - U4C2RV3124 (2,3,4,7,8-pentachlorodibenzofuran)
SB  - IM
MH  - Adenoma, Liver Cell/*chemically induced
MH  - Adipose Tissue/chemistry
MH  - Animals
MH  - Benzofurans/*adverse effects/analysis
MH  - Bile Duct Neoplasms/chemically induced
MH  - Bile Ducts, Intrahepatic
MH  - Body Burden
MH  - Carcinogenicity Tests
MH  - Cholangiocarcinoma/*chemically induced
MH  - Digestive System Neoplasms/*chemically induced
MH  - Humans
MH  - Liver/chemistry
MH  - Liver Neoplasms/chemically induced
MH  - Lung/chemistry
MH  - Models, Biological
MH  - Organ Size
MH  - Polychlorinated Biphenyls/*adverse effects/analysis
MH  - Polychlorinated Dibenzodioxins/*adverse effects/analysis
MH  - Risk Assessment
EDAT- 2006/05/27 09:00
MHDA- 2006/06/29 09:00
CRDT- 2006/05/27 09:00
PHST- 2006/05/27 09:00 [pubmed]
PHST- 2006/06/29 09:00 [medline]
PHST- 2006/05/27 09:00 [entrez]
AID - K6M7047W24017346 [pii]
AID - 10.1080/15287390500360042 [doi]
PST - ppublish
SO  - J Toxicol Environ Health A. 2006 May;69(10):907-17. doi: 
      10.1080/15287390500360042.