tamoxifen


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Related to tamoxifen: Nolvadex, Tamoxifen citrate

tamoxifen

(təmŏk`sĭfĕn'), synthetic hormone used in the treatment of breast cancerbreast cancer,
cancer that originates in the breast. Breast cancer is the second leading cause of cancer death in women (following lung cancer). Although the vast majority of the cases occur in women, some men also get breast cancer.
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. Introduced in 1978, tamoxifen is used to prevent recurrences of cancer in women who have already undergone surgery to remove their tumors and to control metastatic breast cancer. In breast tissue, tamoxifen blocks the effect of estrogen on cancerous cells that need estrogen to grow; not all breast cancers are affected by tamoxifen and other selective estrogen receptor modulators. In postmenopausal women with breast cancer, aromatase inhibitors, which block the production of estrogen outside the ovaries, are typically used instead of tamoxifen. In 1998, a large study of healthy women at high risk for breast cancer showed that tamoxifen can also prevent first occurrence of the disease; women who took the drug had a 45% lower incidence of cancer that those who received a placebo, and tamoxifen is now also used to reduce the risk of breast cancer in high risk patients. Adverse effects include and increased risk of uterine and endometrial cancer, blood clots, stroke, and cataracts.
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The researchers found that the eight-year disease-free survival rate was 78.9, 83.2, and 85.9 percent for tamoxifen alone, tamoxifen plus ovarian suppression, and exemestane plus ovarian suppression, respectively, in SOFT.
Tamoxifen works like a broken key in a lock - it sticks to the oestrogen receptor, preventing the normal "key" (oestrogen) from fitting any more, thereby stopping the tumour in its tracks.
Some studies have shown that cotreatment with luteinizing hormone-releasing hormone (LHRH) agonists and continuation of tamoxifen resolves ovarian hyperstimulation and that LHRH agonists are given by monthly injections for 3 or 6 months [4, 5].
Tamoxifen belongs to selective estrogen receptor modulators (SERMs) class of drugs, which is having both estrogenic and anti-estrogenic effects.
"Through this approach, we discovered that tamoxifen has pharmacological properties that could aid the immune system in cases where a patient is immunocompromised or where traditional antibiotics have otherwise failed." Tamoxifen targets the estrogen receptor, making it particularly effective against breast cancers that display the molecule abundantly.
Those who didn't receive chemotherapy based upon a decision made with their physician had excellent outcomes with 5 years of tamoxifen alone, with a 95.8% disease-free survival at 5 years.
Firstly we need to understand a bit about how Tamoxifen acts......
He found that during winter months when vitamin D levels were lowest, nearly 30% of breast cancer patients had less than optimal amounts of endoxifen--and benefitted less from receiving tamoxifen. The reason: patients lacked enough CYP2D6, a protein needed to convert tamoxifen into endoxifen.
Daily tamoxifen for five years, which is the current practice, is known to reduce death rates by around a third during the first 15 years after diagnosis.
Bioactivation of tamoxifen to endoxifen depends in large part upon the function of the P450 enzyme CYP2D6.
And it confirms tamoxifen remains an important treatment for breast cancer, particularly in pre-menopausal women not suitable for the newer drugs aromatase inhibitors.