Use of tamoxifen in the treatment of breast cancer
Overview or what is tamoxifen
Tamoxifen is a tablet used for hormone therapy of breast cancer. Its application in breast cancer treatment stretches back to decades i.e. for almost more than 30 years, due to its ability to stop or slow down growth of cancer cells.
Mode of action
Many cancerous cells are estrogen receptor positive (ER +). Estrogen is the hormone that triggers growth of ER + cells, thereby making the cancer metastatic or invasive in nature. Tamoxifen has the ability to stop estrogen molecule from binding to these estrogen positive cancerous cells.
Thus it’s mode of action is – it’s anti estrogen property, which prevents ER + breast cancer cells from growing. It can also shrink a metastatic tumour.
When it is used?
Tamoxifen is prescribed to women who are at high risk of developing breast cancer as it can prevent recurrence. The medical history, family history (of breast cancer) and the age of the individual are also taken into consideration before administering tamoxifen.
It can be used after a surgery or radiation therapy for breast cancer as an adjuvant and also during the early stages of non invasive breast cancer.
Doctors use tamoxifen in women of all age groups i.e. pre menopausal women and postmenopausal women who can't have an aromatase inhibitor or have chances of recurrence of breast cancer.
When it is not used?
Tamoxifen is not used in a pregnant or breast feeding woman and also if she is planning for pregnancy. Women who had a history of stroke, heart attack, blood clots or taking anticoagulants are not appropriate candidates for tamoxifen hormone therapy.
Such issues need to be addressed to your doctor before initiating the treatment.
How effective is tamoxifen for treating breast cancer?
Tamoxifen is a highly effective drug for breast cancer treatment. Not only does it lower chances of recurrence, it also prevents occurrence of breast cancer in the opposite breast by 40%.
A clinical trial report has revealed that tamoxifen treatment has reduced both invasive and non-invasive breast cancer by 50%. Thus, it greatly improves survival rates in women with ER + breast cancer.
How is tamoxifen taken?
Tamoxifen is taken by mouth, most often as a pill.
Dosing of tamoxifen for breast cancer
The dosing will be completely determined by your doctor. However, in most cases Tamoxifen is prescribed at 20 mg a day for 5 years. When used as an adjuvant it could be 10 mg orally 2 to 3 times a day for 5 years. The tablets may be taken once or twice a day.
How long is tamoxifen used?
It is advised for 5 years for women with ER positive invasive breast cancer.
Doctors consider that post menopausal women who can have aromatase inhibitor; tamoxifen is first continued for 2 or 3 years, followed by an aromatase inhibitor.
Currently, clinical trials have shown that stretching the dosage duration to 10 years instead of 5 years can reduce the risk of the cancer recurrence and increase survival rate much more.
Side effects of tamoxifen treatment for breast cancer
Some side effects include hot flashes, vaginal dryness, weight gain, fluid retention, irregular periods, nausea, vomiting etc. It might also increase risks of stroke, endometrial cancer, etc.
However, doctors say that use of tamoxifen in the treatment of breast cancer is a huge success. Remember it’s a prescription drug and so follow the instructions correctly to increase your survival rates for breast cancer.
Date last updated: January 17, 2015