The 216aHydroxylated Estrogen Breast Cancer Risk Hypothesis

On the basis of the studies described above, which showed that increased formation of 16a-hydroxylated metabolites relative to 2-hydroxy-lated estrogen metabolites may be associated with an elevated risk of breast cancer, it was hypothesized that a low urinary 2-hydroxyestrone to 16a-hydroxyestrone ratio should be inversely associated with breast cancer risk.144 Development of a competitive-type enzyme immunoas-say (EIA) method for quantifying these metabolites in urine145 allowed the...

Hydroxysteroid Dehydrogenases In Breast Epithelial Cells

Both 17HSD1 and 17HSD2 are expressed in normal breast tissue,23,51 and recent investigations suggest that the oxidative (type 2) activity is the dominant form in nontumorous breast cells.51-53 In a study in which a total of 22 samples was analyzed, 17HSD1 protein was detected in most of the normal breast samples from women having regular menstrual cycles and in all samples from women using hormonal con-traception.23 The type 1 enzyme is expressed in epithelial cells of ducts and alveoli...

References

On the treatment of inoperable cases of carcinoma of the mamma suggestions for a new method of treatment with illustrative cases. Lancet 2 104, 1896. 2. Bittner JJ. The causes and control of mammary cancer in mice. Harvey Lect 42 221, 1946-1947. 3. Bittner JJ. The genesis of breast cancer in mice. Texas Rep Biol Med 10 160, 1952. 4. Rous P, Kidd JG. Conditional neoplasms and subthreshold neoplastic states. J Exp Med 73 365, 1941. 5. Berenblum I. Cocarcinogenesis. Br Med Bull 4 343,...

Italian Study

The third tamoxifen prevention study, performed in Italy, began in October 1992 and randomized 5408 women aged 35-70 to 20 milligrams of tamoxifen or placebo daily for 5 years.161 Originally, 20,000 volunteers without risk factors were sought, but the study was stopped prematurely because of poor recruitment and compliance. Women were required to have had a hysterectomy for a nonneoplastic condition to obviate concerns about an increased risk of endometrial carcinoma. There was no requirement...

Raloxifene

Figure 12.11 Comparison of the molecular structures of new and established selective estrogen receptor modulators. ance, 2 not be cross-resistant with tamoxifen, and 3 have fewer side effects such as a lower incidence of endometrial cancer observed with tamoxifen. Steroidal antiestrogens have been developed and have proven to be antiestrogenic in all target tissues206 through premature destruction of the ER.207,208 The pure antiestrogens are effective in laboratory models as second-line...

Info

SRC-1, steroid receptor coactivator 1 ACTR, activating cofactor of thyroid and retinoid receptors RAC, receptor associated cofactor AIB, amplified in breast cancer P CIP, p300 cyclic adenosine monophosphate cAMP response element binding protein CREB binding protein cointegrator protein TRAM, thyroid receptor activator molecule GRIP, glucocorticoid receptor interacting protein TIF, transcription intermediary factor TRIP, thyroid receptor interacting protein SUG, suppressor of Gal4 ARA, androgen...