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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1999-7-22
pubmed:abstractText
Breast cancer is the most common cancer and the second most frequent cause of cancer death in women. Despite extensive research, the precise mechanisms of breast carcinogenesis remain unclear. One of the reasons for this is due, at least in part, to a lack of a suitable animal model which can closely mimic the breast carcinogenesis in normal situations without using chemical carcinogens. We have developed an animal model of mammary gland carcinogenesis using a combination of oestradiol and testosterone, and succeeded in inducing a high percentage of female Noble rats to develop mammary cancer in a relatively short time (approximately 6 months). The results showed that androgens might work as a promoter to shorten the latency time of mammary gland carcinogenesis. Histopathological examination revealed that hyperplasia and dysplasia were first observed 2 months after treatment, in situ carcinoma after 3 months, and fully developed carcinoma of various forms including cribriform, papillary and camedo types were observed from 5 to 6 months after hormone implantation. Animals implanted with oestrogen or testosterone alone also developed mammary cancers, though with a lower overall incidence than the two hormones combined. They ranged from well differentiated to poorly differentiated forms with predominantly infiltrating ductal carcinoma. We have also observed a case of secondary cancer in the uterus. In addition to the high incidence of carcinoma, there was also a peculiar unexplained ipsilateral correlation between the site of hormonal implantation and the location of tumours, and the highest incidence of carcinogenesis was found to be in thoracic mammary gland. The study showed that both oestrogens and androgens are important in mammary cancer development. The animal model would prove to be a useful model for analysis of the mechanism(s) of hormonal carcinogenesis.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0143-3334
pubmed:author
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1069-78
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Induction of high incidence of mammary tumour in female Noble rats with a combination of 17beta-oestradiol and testosterone.
pubmed:affiliation
Department of Anatomy, Faculty of Medicine, University of Hong Kong, Li Shu Fan Building, 5 Sassoon Road, Hong Kong.
pubmed:publicationType
Journal Article