Treatment Name: Tamoxifen
How does tamoxifen work?
Tamoxifen is designed to block estrogen receptors on the surface of breast cancer cells. In patients with Estrogen Receptor positive (ER+) disease, estrogen binds to these receptors and causes the breast cancer cells to grow and divide out of control. Tamoxifen blocks this signal and helps stop the breast cancer cells from growing. It can be taken by both pre-menopausal and post-menopausal women.
Goals of therapy:
Tamoxifen is commonly taken to maintain remission, prevent recurrence of breast cancer and increase the likelihood of cure. It is usually taken for three to five years.
- Usual starting dose: Tamoxifen 20 mg oral tablet by mouth daily
Tamoxifen is dispensed by a pharmacy and taken at home.
It is taken for three to five years, then followed by an oral aromatase inhibitor such as anastrozole or letrozole. Tamoxifen is discontinued if unacceptable side effects occur.
In clinical studies, the most commonly reported side effects with tamoxifen are shown here. Side effects sometimes have percentage ranges [example: 38–40% for hot flashes] because they differed between in clinical studies:
How often is monitoring needed?
Labs (blood tests) may be checked every one to three months. Labs often include: Complete Blood Count (CBC), and Comprehensive Metabolic Panel (CMP)
How often is imaging needed?
Imaging may be checked before treatment and every two to six months during treatment. Imaging may include: bone scans, magnetic resonance imaging (MRI), and computerized tomography (CT) scans.
How might blood test results/imaging affect treatment?
Depending upon the results, your doctor may advise to continue tamoxifen as planned, or delay or switch therapy.
- Hot flashes are one of the most commonly reported side effects with tamoxifen. If this is having a significant effect on everyday life, talk to your doctor about ways to minimize and treat hot flashes. There are many herbal medications and natural supplements that claim to help treat hot flashes. These medications could interact with tamoxifen or other medications you are taking. Do not take any medicines, herbs, or natural supplements without speaking with your doctor or pharmacist first
- Tamoxifen is also available in an oral solution. Talk to your doctor about switching to the oral solution if you are having trouble swallowing the oral tablets
- There are many possible drug interactions with tamoxifen that may decrease the effectiveness of tamoxifen or increase the risk of side effects. Talk to your doctor or pharmacist before starting any new medication. Two SSRI drugs, fluoxetine and paroxetine, are known to decrease effects of tamoxifen. A pharmacist should ALWAYS review your medication list to ensure that drug interactions are prevented or managed appropriately
- Clinical trials may exist for breast cancer. Ask your doctor if any studies are currently enrolling in your area. If not, go to clinicaltrials.gov to search for other centers offering study medications.
Patient Assistance & Co-payment Coverage
Patients under the age of 65 years, or those with private insurance plans:
If you have insurance and are looking for patient assistance or copay assistance for Tamoxifen, we have provided links that may help.
Visit our Patient Assistance page and click the links to various patient assistance programs for help paying for Tamoxifen. Depending upon your income, they may be able to help cover the cost of:
For Branded medications (may be available for generic medications too), check with the manufacturer to determine if a co-pay card is offered and if it could reduce your monthly copay.
- If you are uninsured, check with the manufacturer to determine if you are eligible to receive medication at no cost.
Medicare and Medicaid patients (Patients 65 years or older):
The clinic providing treatment will likely pre-authorize medications and immune therapies such as Tamoxifen and are the best source to help you understand drug cost.
- Ask to speak with a patient assistance technician or financial counselor at the clinic or hospital administering this therapy.
What is Emotional Wellness?
Emotional wellness is having a positive outlook balanced with a realistic understanding of current life events. This requires both an awareness and acceptance of your emotions. It is with this knowledge that you can develop a plan to take the necessary actions to positively impact your life.
Emotional wellness uses an ongoing process to continually reflect on the stressors of life in a constructive manner to move forward and create happiness.
Because emotional wellness is deeply connected with physical, social, and spiritual wellness, pursuing it often becomes particularly difficult in times of major illness. Despite this difficulty, working toward emotional wellness has been connected to improved treatment outcomes and a higher likelihood of achieving goals of therapy.
Learn more about pursuing emotional wellness while receiving treatment with Tamoxifen
What is Breast Cancer - early stage?
What is Early Stage Breast Cancer?
A disease of either the milk-producing glands known as lobules, or milk ducts, or other cells found in the breast. Early stage breast cancer may also affect the lymph nodes, but has not usually spread to other areas of the body. Breast cancer is the most common type of cancer diagnosed in women, but may rarely affect men as well. Breast cancer cells may have increased expression of estrogen receptors (ER positive or negative), progestin receptors (PR positive or negative), and/or HER-2 receptors (HER-2 positive or negative). The presence or lack of these receptors will help determine the most effective chemotherapy medications to give.
Genetic causes, such as the BRCA (pronounced "Bracka") mutation, significantly increase the risk of developing breast cancer. Other risk factors for breast cancer include family history of breast cancer, high fat diet, and obesity. The stage of breast cancer can vary at diagnosis and throughout treatment. Stages of breast cancer include I, II, III, and IV. The effectiveness of the treatment may depend upon the stage at diagnosis.
Types of breast cancer:
1. Hormone-receptor positive or negative (60 - 65% of patients)
- Estrogen Receptor positive (ER)+ or negative (ER)-
- Progestin Receptor positive (PR)+ or negative (PR)-
2. Hormone Epidermal growth factor Receptor-2 (HER-2) positive or negative (20 - 25% of patients)
- HER-2 + (positive)
- HER-2 - (negative)
3. Triple Negative (15 - 18% of patients)
NOTE: Treatment Options listed below are not all-inclusive. Other treatments may be available. ChemoExperts provides drug information and does not recommend any one treatment over another. Only your Doctor can choose which therapy is appropriate for you.
What is a CBC?
A Complete Blood Count (CBC) is a frequently ordered blood test that tells clinicians the status of your: 1) White blood cell count, 2) Hemoglobin, and 3) Platelet count at the time the test was taken.
1) White blood cell count (WBC): is used to determine infection risk, or response to chemotherapy. Certain chemotherapy agents may harm our good infection-fighting cells. Sometimes chemotherapy may need to be delayed to allow these cells to recover.
2) Hemoglobin: is used to determine if someone is anemic. Anytime the hemoglobin is below 12 g/dL, the person is said to be anemic. Red blood cell transfusions, and sometimes iron can be given to restore the hemoglobin level, but anemia treatment should always aim at treating the underlying cause or condition.
3) Platelet count: is used to determine if the risk of bleeding is increased or if a platelet transfusion is required to prevent bleeding. Certain medications that increase bleeding risk, such as: aspirin, certain chemotherapy agents, and blood thinners, may need to be stopped temporarily until the platelet count is within a safe range.
What is a CMP?
A Comprehensive Metabolic Panel (CMP) is a frequently ordered blood test that tells clinicians the status of your: 1) Electrolytes & Acid/Base status, 2) Kidney function, 3) Liver function, 4) Blood sugar, and 5) Calcium at the time the test was taken. It is commonly used to monitor liver and kidney function when beginning new medications such as chemotherapy. A total of 14 tests are run simultaneously and are shown below.
Electrolytes & Acid/Base status:
1) Sodium, 2) Potassium, 3) Carbon dioxide, 4) Chloride
5) BUN (blood urea nitrogen), 6) Serum creatinine (Scr)
7) AST, 8) ALT, 9) Total bilirubin, 10) Alk Phos, 11) Albumin, 12) Total protein
13) Serum glucose
14) Serum calcium
If you are interested in reading the clinical trials results, please click on references below:
1. The ATAC (Arimidex, Tamoxifen Alone or in Combination) Trialists’ Group. Anastrozole alone or in combination with tamoxifen versus tamoxifen alone for adjuvant treatment of postmenopausal women with early breast cancer: first results of the ATAC randomised trial. Lancet. 2002;359:2131-2139.
2. The Breast International Group (BIG) 1-98 Collaborative Group. A Comparison of Letrozole and Tamoxifen in Postmenopausal Women with Early Breast Cancer. N Engl J Med. 2005;353:2747-2757.
3. Allred DC, Anderson SJ, Paik S, et al. Adjuvant tamoxifen reduces subsequent breast cancer in women with estrogen receptor-positive ductal carcinoma in situ: a study based on NSABP protocol B-24. J Clin Oncol. 2012;30:1268-1273.