A report on Raloxifene, Selective estrogen receptor modulator, Tamoxifen and Breast cancer

Tamoxifen, a nonsteroidal triphenylethylene antiestrogen and a widely used drug in the treatment of breast cancer.

Figure 2: Nolvadex (tamoxifen) 20-milligram tablets (UK)

Crystallographic structure of afimoxifene (carbon = white, oxygen = red, nitrogen = blue) complexed with ligand binding domain of estrogen receptor alpha (ERα) (cyan ribbon).

Breast cancer showing an inverted nipple, lump, and skin dimpling

Figure 3: The domain structures of ERα and ERβ, including some of the known phosphorylation sites involved in ligand-independent regulation.

Figure 4: Structural basis for the mechanism of estrogen receptor agonist and antagonist action. The structures shown here are of the ligand binding domain (LBD) of the estrogen receptor (green cartoon diagram) complexed with either the agonist diethylstilbestrol (top, ) or antagonist 4-hydroxytamoxifen (bottom, ). The ligands are depicted as space filling spheres (white = carbon, red = oxygen). When an agonist is bound to a nuclear receptor, the C-terminal alpha helix of the LBD (H12; light blue) is positioned such that a coactivator protein (red) can bind to the surface of the LBD. Shown here is just a small part of the coactivator protein, the so-called NR box containing the LXXLL amino acid sequence motif. Antagonists occupy the same ligand binding cavity of the nuclear receptor. However antagonist ligands in addition have a sidechain extension which sterically displaces H12 to occupy roughly the same position in space as coactivators bind. Hence coactivator binding to the LBD is blocked.

Tumor in the breast visualized by Breast-Computertomography (Breast-CT)

Figure 5: 4-hydroxytamoxifen (red) overlaid with 17β-estradiol (black)

All types of alcoholic beverages, including beer, wine, or liquor, cause breast cancer.

Figure 6: Trans-form of clomifene with the triphenylethylene structure in red.

Ducts and lobules, the main locations of breast cancers

Figure 8: Chemical structure of toremifene

Overview of signal transduction pathways involved in programmed cell death. Mutations leading to loss of this ability can lead to cancer formation.

Figure 9: Raloxifene has a benzothiophene group (red) and is connected with a flexible carbonyl hinge to a phenyl 4-piperidinoethoxy side chain (green).

Histopathologic types of breast cancer, with relative incidences and prognoses

Figure 10: Chemical structure of nafoxidine with the dihydronapthalene group in red.

A mobile breast cancer screening unit in New Zealand

Figure 11: Chemical structure of lasofoxifene shows cis-oriented phenyls.

Figure 12: Bazedoxifene includes an indole system (red) which is connected to an amine through a benzyloxyethyl chain (green).

Figure 13: Chemical structure of ospemifene. Ethoxy side chain ends with a hydroxy group (red) instead of a dimethylamino group as with first-generation SERMs.

Breasts after double mastectomy followed by nipple-sparing reconstruction with implants

Figure 14: The ABCD steroid ring system in 17β-estradiol.

An extreme example of an advanced recurrent breast cancer with an ulcerating axillary mass

Figure 15: "A ring" (A) and "D ring" (D) marked in raloxifene.

Radical mastectomy, Halsted's surgical papers

The pink ribbon is a symbol to show support for breast cancer awareness.

Excised human breast tissue, showing an irregular, dense, white stellate area of cancer 2cm in diameter, within yellow fatty tissue

High-grade invasive ductal carcinoma, with minimal tubule formation, marked pleomorphism, and prominent mitoses, 40x field

Micrograph showing a lymph node invaded by ductal breast carcinoma, with an extension of the tumor beyond the lymph node

Neuropilin-2 expression in normal breast and breast carcinoma tissue

F-18 FDG PET/CT: A breast cancer metastasis to the right scapula

Elastography shows stiff cancer tissue on ultrasound imaging.

Ultrasound image shows irregularly shaped mass of breast cancer.

Infiltrating (invasive) breast carcinoma

Mammograms showing a normal breast (left) and a breast with cancer (right)

Tamoxifen, sold under the brand name Nolvadex among others, is a selective estrogen receptor modulator used to prevent breast cancer in women and treat breast cancer in women and men.

- Tamoxifen

It is also used to reduce the risk of breast cancer in those at high risk.

- Raloxifene

Tamoxifen is a first-line hormonal treatment of ER-positive metastatic breast cancer.

- Selective estrogen receptor modulator

Raloxifene is a selective estrogen receptor modulator (SERM) and therefore a mixed agonist–antagonist of the estrogen receptor (ER).

- Raloxifene

Raloxifene is used for prevention and treatment of postmenopausal osteoporosis and breast cancer prevention in high-risk postmenopausal women with osteoporosis.

- Selective estrogen receptor modulator

The medications tamoxifen or raloxifene may be used in an effort to prevent breast cancer in those who are at high risk of developing it.

- Breast cancer

In 2006, the large STAR clinical study concluded that raloxifene is also effective in reducing the incidence of breast cancer.

- Tamoxifen

In the Study of Tamoxifen and Raloxifene (STAR) trial, 60 mg/day raloxifene was 78% as effective as 20 mg/day tamoxifen in preventing non-invasive breast cancer.

- Raloxifene

Toxicological issues prevented long term use of clomifene and further drug development for other potential applications such as breast cancer treatment and prevention.

- Selective estrogen receptor modulator

The selective estrogen receptor modulators reduce the risk of breast cancer but increase the risk of thromboembolism and endometrial cancer.

- Breast cancer

1 related topic with Alpha

A dimer of the ligand-binding region of ERβ (PDB rendering based on ).

Estrogen receptor

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Estrogen receptors (ERs) are a group of proteins found inside cells.

The domain structures of ERα and ERβ, including some of the known phosphorylation sites involved in ligand-independent regulation.

A dimer of the ligand-binding region of ERα (PDB rendering based on ).

The ERα is found in endometrium, breast cancer cells, ovarian stromal cells, and the hypothalamus. In males, ERα protein is found in the epithelium of the efferent ducts.

Selective estrogen receptor modulators (e.g., tamoxifen, clomifene, raloxifene)