October 10, 2011

Treatment of Breast Cancer Prevention

Selective estrogen receptor modulators (SERMs) and the effect of estrogen on breast cell growth

A selective estrogen receptor modulators (SERMs) is a chemical that is made to work like estrogen in certain network such as the bones and do not like estrogen in other tissues such as breast. The use of SERMs to take profit of the benefits of estrogen while trying to avoid the risks associated with estrogen. Two SERMs, Tamoxifen and Raloxifene, has been used as preventive treatment. The advantages and disadvantages of either discussed in more details below.



Tamoxifen

Tamoxifen (Nolvadex) is the first SERM which received approval from the FDA in the treatment of breast cancer. Some breast cancer cells are sensitive to estrogen (estrogen-insensitive), which means they have what is called estrogen receptors (estrogen receptors of cells) and require estrogen to grow and divide. However, estrogen should tie
themselves to receptors of cancerous cells to stimulate them. Estrogen binds to receptors is the same as installing a key into a keyhole. Tamoxifen blocks the action of estrogen on cancer cells by occupying the receptors, so it prevents estrogen from increase himself into the receptors. Blocking estrogen from cancer cells are estrogen sensitive dismiss the growth and multiplication of these cells. Tamoxifen (in higher doses than usual) may also have other riches that causes the death of breast cancer cells are not sensitive to estrogen.

Tamoxifen has been used to treat both cancer-and early-stage breast cancer that has continued. This drug has been proven beneficial in women who have had cancer in one breast in reducing the possibilities of developing breast cancer in both.

Although tamoxifen behaves as an element of anti-estrogens in breast tissue, it works like a weak estrogen in the bones. Thus, tamoxifen may have some benefit in preventing cracks / fractures caused by osteoporosis in women who already had menopause.

Tamoxifen also reduces cysts (cysts) and lumps (lumps) on the breasts, especially among women younger. Cysts and lumps are much less make the early detection examinations and mammograms, breast mammograms easier. Use of these drugs only in extreme situations and not an approved use.
Aromatase inhibitors
Primary prevention (primary) of breast cancer with tamoxifen

The term "primary prevention" means trying to reduce the risks of developing breast cancer in women without a previous history of breast cancer. Tamoxifen not only blocks the action of estrogen on cancer cells are estrogen sensitive, but it also blocks estrogen from working in cells that are not cancerous. Therefore, by reducing the growth and division of cells of normal breast, tamoxifen reduces the population of cells that can develop cancer-causing DNA damage.

In the project "The National Surgical Adjuvant Breast and Bowel Project (NSABP) P-1", more than 13,000 women who were considered at high risk of developing breast cancer are given tamoxifen or a placebo for five years. The women who received tamoxifen developed 49% fewer breast cancers than women who received placebo. A further study, the International Breast Cancer Intervention Study (IBIS-I) in Europe, also confirmed a reduction in number of breast cancer development in women at high risk.

The United States Food and Drug Administration (FDA) has approved the use of tamoxifen for primary prevention in women at high risk of developing breast cancer. There is no evidence to suggest that tamoxifen may reduce the incidence of breast cancer in women who are considered to have a normal person is at risk of developing breast cancer.
The risks and side effects of tamoxifen

The risk of tamoxifen is the development of uterine cancer. Although the risk of developing uterine cancer as a whole is small (probably less than 1%), the NSABP-P1 trial, more women receiving tamoxifen developed uterine cancer than women who received placebo.

In addition, women aged over 50 years who received tamoxifen had a slightly increased chance of developing blood clots in the veins-veins in the legs. These blood clots can sometimes come off and running, causing blockages in blood vessels in the lungs (a process called pulmonary embolism). The symptoms of pulmonary embolism include shortness of breath, chest pain, and sometimes shock. Several studies also have reported an increased risk of stroke in patients who received tamoxifen.

Other side effects of tamoxifen include weight gain, hot (hot flashes), came menstrual irregularities, vaginal dryness, and a small increase of the risk of cataracts.

Many of these side effects also depends on the age group being studied.


Raloxifene (Evista)

Raloxifene is a SERM approved by the FDA. He has been approved for use in preventing osteoporosis in women after menopause. The data suggest that raloxifene, like tamoxifen, can reduce the likelihood of developing breast cancer in women at high risk. Unlike tamoxifen, raloxifene does not stimulate the cells of the womb, and is believed to increase risk of uterine cancer.


Studies that examined the effects of both tamoxifen and raloxifene (STAR
​​trial included, who studied more than 19.000 women after menopause are at high risk of developing breast cancer) showed that both drugs reduce the incidence of breast cancer in a manner similar . While both tamoxifen and raloxifene increase a woman's risk for blood clots, the observed increase is smaller with raloxifene. Raloxifene is also associated with a lower risk of uterine cancer and a hysterectomy for reasons that are not cancer than tamoxifen. However, some data suggest that raloxifene may not be as effective as tamoxifen in preventing the progression of early cancers that are not invasive.

Data from the effects of raloxifene in women before menopause is not available, and it is a potential teratogen, which means that it can cause damage to fetal development. Therefore, raloxifene is limited its use by women after menopause and is not used in women to bear children ages.
Controversies or concerns, other concerns about the use of tamoxifen or raloxifene as a primary prevention for high risk patients

The data from studies of raloxifene and tamoxifen are encouraging. But there are still issues unresolved such as:

1.       Are women treated with tamoxifen or raloxifene for primary prevention has a long-term survival rates are higher than in women who received placebo?
2.       Whether tamoxifen or raloxifene actually prevent breast cancer, or they only suppress the growth of breast cancer that already exists, so slow detection?
3.       If tamoxifen given to women who are healthy and young, what side effects long term? Is the reduction in breast cancer translated into long-term survival and quality of life better?
4.       How many years of patients  must be maintained on drugs?
Selecting groups of high-risk women for whom a preventive drug such as tamoxifen or raloxifene should be considered its use as a primary prevention

A special model has been developed to assist physicians in predicting / predict the risks of breast cancer patients. This model is used on a trial of tamoxifen in the NSABP and is available to help evaluate patients who are considering this question. Some doctors will recommend considering tamoxifen to patients perimenopausal (the years around menopause) or raloxifene for postmenopausal patients with multiple first-degree relatives who have breast cancer if the patients had biopsies with cellular changes abnormal but not yet cancerous (atypical hyperplasia) or a type of localized breast cancer (lobular carcinoma in situ). This recommendation would be even stronger if the patient had a hysterectomy.

Studies are also under way to determine whether tamoxifen or raloxifene is effective in preventing breast cancer in women with the genes BRCA1 or BRCA2 is inherited.

Aromatase inhibitors

Other drugs, known collectively as the aromatase inhibitors, are also used to block the effects of estrogen. Their main activity is to inhibit (block) the action of a specific enzyme (aromatase) that creates estrogen from other hormones that normally circulate. Tamoxifen and aromatase inhibitors, therefore, works differently and has side effects are different. Studies are in progress to compare their use as drug-drug prevention of breast cancer together and in sequence.
Measures to prevent breast cancer surgery

Preventive or prophylactic mastectomy is the removal of one or both breasts surgically in women who have moderate to high risk of developing breast cancer. Studies have shown that this technique reduces the likelihood of a woman developing breast cancer up to 90%. Because a small amount of breast tissue can remain in the chest wall, in the armpits, or even within the abdomen after a mastectomy, it is impossible to completely prevent the development of breast cancer by prophylactic mastectomy. The women often choose to get reconstruction of breasts surgically at the time of surgical removal of the breast.

It is very important for a woman who is considering preventive mastectomy to have an honest discussion with their doctors regarding the risk of cancer, available treatments other, and the complications and the potential implications of the operation before making a decision.

Read: Actions by Other Breast Cancer Prevention in Here
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Treatment of Breast Cancer Prevention

Selective estrogen receptor modulators (SERMs) and the effect of estrogen on breast cell growth

A selective estrogen receptor modulators (SERMs) is a chemical that is made to work like estrogen in certain network such as the bones and do not like estrogen in other tissues such as breast. The use of SERMs to take profit of the benefits of estrogen while trying to avoid the risks associated with estrogen. Two SERMs, Tamoxifen and Raloxifene, has been used as preventive treatment. The advantages and disadvantages of either discussed in more details below.



Tamoxifen

Tamoxifen (Nolvadex) is the first SERM which received approval from the FDA in the treatment of breast cancer. Some breast cancer cells are sensitive to estrogen (estrogen-insensitive), which means they have what is called estrogen receptors (estrogen receptors of cells) and require estrogen to grow and divide. However, estrogen should tie
themselves to receptors of cancerous cells to stimulate them. Estrogen binds to receptors is the same as installing a key into a keyhole. Tamoxifen blocks the action of estrogen on cancer cells by occupying the receptors, so it prevents estrogen from increase himself into the receptors. Blocking estrogen from cancer cells are estrogen sensitive dismiss the growth and multiplication of these cells. Tamoxifen (in higher doses than usual) may also have other riches that causes the death of breast cancer cells are not sensitive to estrogen.

Tamoxifen has been used to treat both cancer-and early-stage breast cancer that has continued. This drug has been proven beneficial in women who have had cancer in one breast in reducing the possibilities of developing breast cancer in both.

Although tamoxifen behaves as an element of anti-estrogens in breast tissue, it works like a weak estrogen in the bones. Thus, tamoxifen may have some benefit in preventing cracks / fractures caused by osteoporosis in women who already had menopause.

Tamoxifen also reduces cysts (cysts) and lumps (lumps) on the breasts, especially among women younger. Cysts and lumps are much less make the early detection examinations and mammograms, breast mammograms easier. Use of these drugs only in extreme situations and not an approved use.
Aromatase inhibitors
Primary prevention (primary) of breast cancer with tamoxifen

The term "primary prevention" means trying to reduce the risks of developing breast cancer in women without a previous history of breast cancer. Tamoxifen not only blocks the action of estrogen on cancer cells are estrogen sensitive, but it also blocks estrogen from working in cells that are not cancerous. Therefore, by reducing the growth and division of cells of normal breast, tamoxifen reduces the population of cells that can develop cancer-causing DNA damage.

In the project "The National Surgical Adjuvant Breast and Bowel Project (NSABP) P-1", more than 13,000 women who were considered at high risk of developing breast cancer are given tamoxifen or a placebo for five years. The women who received tamoxifen developed 49% fewer breast cancers than women who received placebo. A further study, the International Breast Cancer Intervention Study (IBIS-I) in Europe, also confirmed a reduction in number of breast cancer development in women at high risk.

The United States Food and Drug Administration (FDA) has approved the use of tamoxifen for primary prevention in women at high risk of developing breast cancer. There is no evidence to suggest that tamoxifen may reduce the incidence of breast cancer in women who are considered to have a normal person is at risk of developing breast cancer.
The risks and side effects of tamoxifen

The risk of tamoxifen is the development of uterine cancer. Although the risk of developing uterine cancer as a whole is small (probably less than 1%), the NSABP-P1 trial, more women receiving tamoxifen developed uterine cancer than women who received placebo.

In addition, women aged over 50 years who received tamoxifen had a slightly increased chance of developing blood clots in the veins-veins in the legs. These blood clots can sometimes come off and running, causing blockages in blood vessels in the lungs (a process called pulmonary embolism). The symptoms of pulmonary embolism include shortness of breath, chest pain, and sometimes shock. Several studies also have reported an increased risk of stroke in patients who received tamoxifen.

Other side effects of tamoxifen include weight gain, hot (hot flashes), came menstrual irregularities, vaginal dryness, and a small increase of the risk of cataracts.

Many of these side effects also depends on the age group being studied.


Raloxifene (Evista)

Raloxifene is a SERM approved by the FDA. He has been approved for use in preventing osteoporosis in women after menopause. The data suggest that raloxifene, like tamoxifen, can reduce the likelihood of developing breast cancer in women at high risk. Unlike tamoxifen, raloxifene does not stimulate the cells of the womb, and is believed to increase risk of uterine cancer.


Studies that examined the effects of both tamoxifen and raloxifene (STAR
​​trial included, who studied more than 19.000 women after menopause are at high risk of developing breast cancer) showed that both drugs reduce the incidence of breast cancer in a manner similar . While both tamoxifen and raloxifene increase a woman's risk for blood clots, the observed increase is smaller with raloxifene. Raloxifene is also associated with a lower risk of uterine cancer and a hysterectomy for reasons that are not cancer than tamoxifen. However, some data suggest that raloxifene may not be as effective as tamoxifen in preventing the progression of early cancers that are not invasive.

Data from the effects of raloxifene in women before menopause is not available, and it is a potential teratogen, which means that it can cause damage to fetal development. Therefore, raloxifene is limited its use by women after menopause and is not used in women to bear children ages.
Controversies or concerns, other concerns about the use of tamoxifen or raloxifene as a primary prevention for high risk patients

The data from studies of raloxifene and tamoxifen are encouraging. But there are still issues unresolved such as:

1.       Are women treated with tamoxifen or raloxifene for primary prevention has a long-term survival rates are higher than in women who received placebo?
2.       Whether tamoxifen or raloxifene actually prevent breast cancer, or they only suppress the growth of breast cancer that already exists, so slow detection?
3.       If tamoxifen given to women who are healthy and young, what side effects long term? Is the reduction in breast cancer translated into long-term survival and quality of life better?
4.       How many years of patients  must be maintained on drugs?
Selecting groups of high-risk women for whom a preventive drug such as tamoxifen or raloxifene should be considered its use as a primary prevention

A special model has been developed to assist physicians in predicting / predict the risks of breast cancer patients. This model is used on a trial of tamoxifen in the NSABP and is available to help evaluate patients who are considering this question. Some doctors will recommend considering tamoxifen to patients perimenopausal (the years around menopause) or raloxifene for postmenopausal patients with multiple first-degree relatives who have breast cancer if the patients had biopsies with cellular changes abnormal but not yet cancerous (atypical hyperplasia) or a type of localized breast cancer (lobular carcinoma in situ). This recommendation would be even stronger if the patient had a hysterectomy.

Studies are also under way to determine whether tamoxifen or raloxifene is effective in preventing breast cancer in women with the genes BRCA1 or BRCA2 is inherited.

Aromatase inhibitors

Other drugs, known collectively as the aromatase inhibitors, are also used to block the effects of estrogen. Their main activity is to inhibit (block) the action of a specific enzyme (aromatase) that creates estrogen from other hormones that normally circulate. Tamoxifen and aromatase inhibitors, therefore, works differently and has side effects are different. Studies are in progress to compare their use as drug-drug prevention of breast cancer together and in sequence.
Measures to prevent breast cancer surgery

Preventive or prophylactic mastectomy is the removal of one or both breasts surgically in women who have moderate to high risk of developing breast cancer. Studies have shown that this technique reduces the likelihood of a woman developing breast cancer up to 90%. Because a small amount of breast tissue can remain in the chest wall, in the armpits, or even within the abdomen after a mastectomy, it is impossible to completely prevent the development of breast cancer by prophylactic mastectomy. The women often choose to get reconstruction of breasts surgically at the time of surgical removal of the breast.

It is very important for a woman who is considering preventive mastectomy to have an honest discussion with their doctors regarding the risk of cancer, available treatments other, and the complications and the potential implications of the operation before making a decision.

Read: Actions by Other Breast Cancer Prevention in Here