The effect of ovariectomy on excretion of urinary steroids and tumor growth in rats bearing 7,12-dimethylbenz[a]anthracene-induced mammary cancer.
The relation between the excretion of urinary steroids and the therapeutic effect of ovariectomy on tumors was investigated in female Sprague-Dawley rats bearing 7,12-dimethylbenz[a]anthracene-induced mammary cancer. Ovariectomy significantly reduced the excretion of urinary androgen, 11-deoxy-17-oxosteroid (11-DOOS), but hardly affected that of urinary corticosteroid, 17-deoxy-corticosteroid (17-DOCS). The responsiveness of tumors to ovariectomy was positively correlated with both pre-operative 11-DOOS and pre-operative ratio of 11-DOOS to 17-DOCS, and negatively correlated with pre-operative 17-DOCS. The extent of tumor regression after ovariectomy was associated with the decrease of urinary androgen. A similar correlation was observed between the decrease in the ratio 11-DOOS/17-DOCS and tumor suppression during cyclophosphamide treatment (medical ovariectomy). These results indicated that the tumor response to ovariectomy was related to a shift of the endogenous hormone balance from a relative dominance of androgen to relative dominance of corticosteroid. The significance of the hormonal findings is discussed in the light of the steroid metabolism in human breast cancer.
D015127:9,10-Dimethyl-1,2-benzanthracene; D000305:Adrenal Cortex Hormones / Q000652:urine; D000728:Androgens / Q000652:urine*; D000818:Animals; D002369:Castration; D003520:Cyclophosphamide / Q000627:therapeutic use; D005260:Female; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000601:surgery / Q000652:urine*; D009376:Neoplasms, Hormone-Dependent / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D005641:Tegafur / Q000627:therapeutic use
D000305:Adrenal Cortex Hormones; D000728:Androgens; D005641:Tegafur; D015127:9,10-Dimethyl-1,2-benzanthracene; C025404:3-FT; D003520:Cyclophosphamide