Change in chemosensitivity of DMBA-induced rat mammary tumor after oophorectomy.
BACKGROUND
A combination of chemotherapy and endocrine therapy is usually employed for the treatment of breast cancer, but the optimal order of this combination has not yet been verified. To determine the appropriate order of this combination, changes in chemosensitivity to anticancer agents after endocrine therapy were examined.


METHODS
Rat mammary tumors induced by 7,12-dimethylbenz[alpha]-anthracene (DMBA) were used. Chemosensitivity tests were performed before and 3 weeks after bilateral oophorectomy. The MTT assay was used to test eight anticancer agents, and oophorectomy was performed as the endocrine therapy.


RESULTS
DMBA-induced rat mammary tumors showed sensitivity to 4'-0-tetrahydropyranyl-doxorubicin, 5-fluorouracil, peplomycin, mitomycin C, and methotrexate. Chemosensitivity to these agents seemed to be somewhat reduced after oophorectomy compared with before the operation, but the difference was not significant.


CONCLUSIONS
The influence of oophorectomy on chemosensitivity of DMBA-induced mammary tumor is thought to be minimal.
Isogai
M
M
First Department of Surgery, Kumamoto University School of Medicine, Japan.
Kondo
K
K
Kitamura
N
N
D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D005260:Female; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000188:drug therapy*; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley
D015127:9,10-Dimethyl-1,2-benzanthracene