Synergism of diethylstilbestrol and radiation in mammary carcinogenesis in female F344 rats

Journal Article · Mon Oct 01 04:00:00 EDT 1979 · J. Natl. Cancer Inst.; (United States)

OSTI ID:5393478

Holtzman, S; Stone, J P; Shellabarger, C J

One compressed 20-mg pellet containing cholesterol only or chlesterol mixed with 0.98, 1.6, 2.6, or 3.9 mg of diethylstilbestrol (DES) was implanted into each of 203 female F344 rats. Two days later, half the animals in each group were exposed to 150 R of x-ays, and the other half were sham irradiated. The rats were maintained until 350 days post implantation. Mortality increased with the higher doses of DES, with or without x-rays. DES at all dose levels, with or withoug x-rays, produced pituitary tumors and pyometritis. Only rats that received both DES and x-rays had mammary adenocarcinomas (AC). A synergistic AC response was found in the group that received 2.6 mg DES plus x-rays. Synergism was defined as a significantly greater incidence of rats with mammary neoplasia resulting from DES plus x-ray treatment when compared to the summed incidence from comparable individual treatments. For all other groups of rats that received both treatments. For all other groups of rats that received both treatments, synergism was detected only when their data were combined. Synergism was not detected among rats that had fibroadenomas (FA). Both types of neoplasma were independent phenomena because no significant relationship was found between the incidences of FA and AC.

• Research Organization: Brookhaven National Lab., Upton, NY
• OSTI ID: 5393478
• Journal Information: J. Natl. Cancer Inst.; (United States), Journal Name: J. Natl. Cancer Inst.; (United States) Vol. 63:4; ISSN JNCIA
• Country of Publication: United States
• Language: English

Related Subjects

560152* -- Radiation Effects on Animals-- Animals
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ADENOMAS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY
DISEASES
ELECTROMAGNETIC RADIATION
ESTROGENS
GLANDS
HORMONES
IONIZING RADIATIONS
MAMMALS
MAMMARY GLANDS
MORTALITY
NEOPLASMS
ORGANS
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RADIOSENSITIVITY
RADIOSENSITIVITY EFFECTS
RATS
RODENTS
STEROID HORMONES
SYNERGISM
VERTEBRATES
X RADIATION