title: Summary of chemically induced pulmonary lesions in the National Toxicology Program (NTP) toxicology and carcinogenesis studies.
abstract: The lung is the second most common target site of neoplasia of chemicals tested by the National Toxicology Program (NTP). Of all peer-reviewed NTP studies to date (N = 545), a total of sixty-four chemicals in sixty-six reports produced significant site-specific neoplasia in the lungs of rats and/or mice. Of the studies associated with lung tumor induction, approximately 35% were inhalation and 35% were gavage studies, with dosed-feed, dosed-water, topical, intraperitoneal, or in utero routes of chemical administration accounting for 18%, 6%, 3%, 1%, and 1% of the studies, respectively. The most commonly induced lung tumors were alveolar/bronchiolar (A/B) adenoma and/or carcinoma for both species. The most frequently observed nonneoplastic lesions included hyperplasia and inflammation in both species. The liver was the most common primary site of origin of metastatic lesions to the lungs of mice; however, skin was most often the primary site of origin of metastatic lesions to the lungs of rats. In summary, A/B adenoma and carcinoma were the most frequently diagnosed chemically induced tumors in the lungs of both rats and mice in the NTP toxicology and carcinogenesis bioassays, and hyperplasia and inflammation were the most common nonneoplastic changes observed.
authors.affiliation: Cellular and Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA. dixon@niehs.nih.gov
authors.forename: Darlene
authors.initials: D
authors.lastname: Dixon
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Herbert
authors.forename: Grace E
authors.initials: GE
authors.lastname: Kissling
authors.forename: Amy E
authors.initials: AE
authors.lastname: Brix
authors.forename: Rodney A
authors.initials: RA
authors.lastname: Miller
authors.forename: Robert R
authors.initials: RR
authors.lastname: Maronpot
mesh_terms: D000230:Adenocarcinoma / Q000139:chemically induced / Q000556:secondary*; D000236:Adenoma / Q000139:chemically induced / Q000473:pathology*; D000818:Animals; D015197:Carcinogenicity Tests; D002273:Carcinogens / Q000633:toxicity*; D006528:Carcinoma, Hepatocellular / Q000139:chemically induced / Q000556:secondary; D005260:Female; D006965:Hyperplasia / Q000139:chemically induced / Q000473:pathology; D008113:Liver Neoplasms / Q000139:chemically induced / Q000556:secondary; D008175:Lung Neoplasms / Q000139:chemically induced / Q000473:pathology* / Q000556:secondary; D008297:Male; D051379:Mice; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000473:pathology*; D051381:Rats; D011916:Rats, Inbred F344; D012878:Skin Neoplasms / Q000139:chemically induced / Q000556:secondary; D015262:Xenobiotics / Q000633:toxicity*
chemical_list: D002273:Carcinogens; D015262:Xenobiotics