What does it mean when your estrogen receptor is positive?

What does it mean when your estrogen receptor is positive?

Describes cells that have a protein that binds to the hormone estrogen. Cancer cells that are estrogen receptor positive may need estrogen to grow. These cells may stop growing or die when treated with substances that block the binding and actions of estrogen. Also called ER positive.

Is tamoxifen used for her2 positive breast cancer?

Objectives: Tamoxifen is a partial ER antagonist that is highly effective in the treatment of receptor positive breast cancer. It significantly reduces recurrence and improves survival in both pre- and postmenopausal women.

Can cancer become resistant to tamoxifen?

Estrogen-receptor positive (ER+) breast cancer tumors are frequently treated with the drug tamoxifen, which blocks the hormone’s effect on the tumor. However, many tumors eventually become resistant to tamoxifen, allowing cancer to recur or metastasize.

Does tamoxifen downregulate estrogen receptors?

Tamoxifen is a drug commonly used in the treatment of breast cancer, especially for postmenopausal patients. However, its efficacy is limited by the development of drug resistance. Downregulation of estrogen receptor alpha (ERα) is an important mechanism of tamoxifen resistance.

Is it better to be estrogen positive or negative?

Hormone receptor-positive cancers tend to grow more slowly than those that are hormone receptor-negative. Women with hormone receptor-positive cancers tend to have a better outlook in the short-term, but these cancers can sometimes come back many years after treatment.

What percentage of breast cancers are estrogen receptor-positive?

About 80% of all breast cancers are “ER-positive.” That means the cancer cells grow in response to the hormone estrogen. About 65% of these are also “PR-positive.” They grow in response to another hormone, progesterone.

What is a contraindication for tamoxifen?

Tamoxifen is contraindicated in patients who require concomitant anticoagulant therapy or have a history of thromboembolism (e.g., deep vein thrombosis (DVT), pulmonary embolus (PE), stroke) if the indication is risk reduction for high-risk patients or risk reduction of invasive breast cancer after ductal carcinoma in …

Can tamoxifen shrink tumors?

For women with hormone-positive breast cancer that has spread to other parts of the body, tamoxifen can often help slow or stop the growth of the cancer, and might even shrink some tumors.

What causes tamoxifen resistance?

The tamoxifen resistance is caused by estrogen via promoting Bcl-2: Bax ratio by estrogen. Besides, HER-2 overexpression increases the anti-apoptotic Bcl-2 and BclxL proteins which leads to the reduction in tamoxifen induced apoptosis and boosts tamoxifen resistance [20].

Does tamoxifen affect estrogen?

Tamoxifen. Tamoxifen blocks estrogen from connecting to the cancer cells and telling them to grow and divide. While tamoxifen acts like an anti-estrogen in breast cells, it acts like an estrogen in other tissues, like the uterus and the bones. Because of this, it is called a selective estrogen receptor modulator (SERM) …

Where does tamoxifen bind in the cell?

Tamoxifen binds to the estrogen receptor but does not activate it fully, halting estrogen-induced growth.

How does tamoxifen work to treat breast cancer?

In many breast cancers, the presence of estrogen provides “permission” for the cancer cells to grow. Mutations in one or more oncogenes directly cause the uncontrolled growth, and estrogen then promotes the growth of the cancer. The drug tamoxifen rescinds this permission by blocking the reception of the estrogen message.

How does tamoxifen block estrogen reception?

The drug tamoxifen rescinds this permission by blocking the reception of the estrogen message. Tamoxifen binds to the estrogen receptor but does not activate it fully, halting estrogen‐induced growth. Of course, estrogen has many effects throughout the body. It is dangerous to block its action indiscriminately.

Why does tamoxifen not adopt its active conformation?

However, when tamoxifen (in pink in the lower illustration) binds, the extra tail of the drug is too bulky and the receptor loop is not able to adopt its active conformation. Coordinates were taken from entries 1qku and 3ert from the Protein Data Bank ( http://www.pdb.org ).

How do oncogenes cause breast cancer?

Coordinates were taken from entries 1qku and 3ert from the Protein Data Bank ( http://www.pdb.org ). In many breast cancers, the presence of estrogen provides “permission” for the cancer cells to grow. Mutations in one or more oncogenes directly cause the uncontrolled growth, and estrogen then promotes the growth of the cancer.