Hormone therapy for breast cancer is an effective method used to prevent the growth of certain types of cancer. The use of tamoxifen is a recommended treatment option, especially for patients with hormone-sensitive tumors. The active ingredient tamoxifen works by preventing the estrogen hormone in the body from binding to cancer cells. In this article, you will find detailed information about what tamoxifen is and what it is used for, and you will better understand your hormone therapy process.
What Is Hormone Therapy?
Hormone therapy, which has an important place in breast cancer treatment, is an effective treatment method that slows down or stops the growth of cancers that use hormones to grow. This treatment approach is applied especially in breast cancers that are dependent on female hormones.
Definition of hormone therapy in breast cancer
Hormone therapy (hormonotherapy) is actually an anti-hormone therapy. This method works either by preventing hormones from binding to receptors on cancer cells or by reducing hormone production in the body. Female hormones such as estrogen and progesterone trigger the growth of some breast cancers. The treatment works by preventing these hormones from reaching breast cancer cells.
Approximately 65-70% of breast cancers are fueled by the female hormone estrogen. Finding estrogen or progesterone receptors to be positive as a result of examinations performed on the tumor means that the cancer is hormone-sensitive. In this case, the hormonal treatment option comes to the fore.
The main purpose of hormone therapy
The primary goal of hormone therapy is to slow down and stop the growth of hormone-fueled tumors. Additionally, this treatment:
Reduces the risk of cancer recurrence
Can shrink the size of the tumor before surgery
Can bring the spread of the disease to the body under control
Increases overall survival time
Hormone therapy applied after surgical intervention significantly reduces the likelihood of breast cancer reoccurring. If treatment is started before surgery, the tumor may shrink, making it possible to remove less breast tissue.
What is hormone sensitivity?
Hormone sensitivity refers to the response of cancer cells to hormones. Laboratory tests are performed to determine whether a breast cancer is hormone-sensitive. In these tests, the presence of receptors to which hormones can bind on the surface of cancer cells is investigated.
Cancers sensitive to estrogen are called "estrogen receptor positive" (ER+), and those sensitive to progesterone are called "progesterone receptor positive" (PR+). Some cancers can be both estrogen and progesterone receptor positive. If at least 1% of the cancer cells have these receptors, hormone therapy may be considered.
In approximately 70% of breast cancer patients, the tumor is hormone-sensitive. In this patient group, the question of what tamoxifen is gains importance, because hormone drugs such as tamoxifen are frequently used in treatment. However, this treatment has no benefit in patients who are hormone receptor negative.
For the administration of hormone therapy, menopausal status is first evaluated, as different treatment approaches may be required for pre-menopausal and post-menopausal patients. Therefore, it is important to comprehensively examine the patient's hormonal status and the characteristics of the tumor before starting treatment.
Who Is Hormone Therapy Suitable For?
As with every cancer treatment, who is suitable for hormone therapy is a vital question. Not every breast cancer patient may benefit from this treatment, but when applied to the right patient group, highly effective results can be obtained.
Hormone receptor positive patients
Hormone therapy is primarily suitable for breast cancer patients who are hormone receptor positive. According to research, approximately 65-70% of breast cancers are fueled by the female hormone estrogen. In such cancers, tumor cells have receptors to which hormones can bind.
For a tumor to be considered hormone receptor positive:
Estrogen receptor positive (ER+): Indicates that tumor cells are sensitive to the estrogen hormone
Progesterone receptor positive (PR+): Indicates that tumor cells are sensitive to the progesterone hormone
Cancers that have at least one of these two receptors are called "hormone receptor positive" and respond well to hormone drugs such as tamoxifen. On the other hand, it is known that this treatment is not beneficial in patients who are hormone receptor negative.
Differences between pre-menopause and post-menopause
When planning hormone therapy, the patient's menopausal status plays a decisive role in the choice of treatment. Different treatment approaches are applied to women in the pre-menopausal and post-menopausal periods:
In pre-menopausal women:
A hormonal treatment drug called tamoxifen is usually used for 5-10 years
LHRH analogs that suppress ovarian function can also be added to the treatment in high-risk young patients
Sometimes, the removal of both ovaries can also be offered as an option
In post-menopausal women:
Mostly aromatase inhibitors (anastrozole, letrozole, or exemestane) are used for 5 years
If tamoxifen is to be used, aromatase inhibitors can be applied sequentially for another 5 years after 3-5 years of tamoxifen
The reason for this is that estrogen and progesterone hormones are secreted more in pre-menopausal women and stimulate cancer cells more.
How is suitability for treatment determined?
Suitability for hormone therapy is determined as a result of a comprehensive evaluation. This evaluation process includes:
First, tests are performed on the biopsy or the piece taken after surgery to determine the hormone sensitivity of the cancer. If at least 1% of the cancer cells have hormone receptors, treatment may be considered.
Before starting treatment:
Menopausal status is determined
A comprehensive medical history is taken
Mammography and breast ultrasound are requested
Various blood tests are performed
A gynecological examination is performed
In addition, all individual risk factors and family history are evaluated, and the treatment decision is made together with the patient. In some cases, hormone therapy is contraindicated:
In women with breast cancer or a history of breast cancer
In patients with uterine cancer
In those with unexplained vaginal bleeding
In patients with liver disorders
Hormone therapy can be successfully used as a first-line option, especially in advanced breast cancer patients with bone or limited organ spread who are hormone-sensitive.
Hormone Drugs Used in Breast Cancer
Hormone drugs used in breast cancer treatment work by blocking the hormones that trigger the growth of cancer cells. These drugs are generally effective for hormone receptor-positive breast cancers and work in different ways.
What is tamoxifen and what does it do?
Tamoxifen is one of the most commonly used hormone drugs in breast cancer treatment. This drug works by blocking estrogen receptors and prevents hormones from telling cancer cells to grow. Both women who are menstruating (pre-menopausal) and those who are in menopause (post-menopausal) can use tamoxifen.
Tamoxifen stops the growth of breast cancer cells by preventing estrogen from binding to its receptor. In this way:
It reduces the risk of breast cancer recurrence
It lowers the risk of cancer forming in the opposite breast
It reduces the risk of death from breast cancer
Tamoxifen also offers non-cancer health benefits such as strengthening bone tissue. It is usually used in the form of a pill taken once a day, and the duration of treatment can vary between 5-10 years.
What is the active ingredient of tamoxifen?
The active ingredient of tamoxifen is tamoxifen citrate and it is found in a dose of 30.4 mg equivalent to 20 mg of tamoxifen. Tamoxifen belongs to a class of drugs known as selective estrogen receptor modulators (SERMs). This drug works by binding to estrogen receptors and blocks the effect of estrogen in breast tissue, while acting like estrogen in some other tissues such as bone.
There are some situations to be aware of when using tamoxifen. In particular, it may increase the risk of developing uterine lining cancer. Therefore, regular gynecological check-ups are important during treatment.
What are aromatase inhibitors?
Aromatase inhibitors are drugs that stop estrogen production in the body. These drugs work by blocking the aromatase enzyme that converts the androgen hormone into a small amount of estrogen in the body. There are three main aromatase inhibitors:
Anastrozole (Arimidex)
Letrozole (Femara)
Exemestane (Aromasin)
Aromatase inhibitors are particularly effective in post-menopausal women because in pre-menopausal women, the ovaries produce more aromatase than the inhibitors can effectively block. These drugs are usually used in the form of a pill taken once a day, and the duration of treatment is between 5-10 years.
The most important side effects of these drugs include joint-muscle pain and osteoporosis. Therefore, it is important to have bone density measurements performed before starting treatment and during treatment.
GnRH agonists and other options
GnRH (Gonadotropin-releasing hormone) agonists are drugs that suppress ovarian function. In pre-menopausal women, they are used to temporarily stop the ovaries from producing estrogen. GnRH agonists include:
Goserelin
Leuprolide (Leuprolide) is found
Reversible treatment using GnRH agonists for ovarian suppression is a preferred option for many pre-menopausal breast cancer patients. Especially in high-risk young patients under 40, LHRH analogs can be applied for up to 5 years after chemotherapy.
Selective estrogen receptor degraders (SERDs) such as fulvestrant are other drugs used in hormone therapy. These drugs bind to estrogen receptors and cause the receptors to degrade. Fulvestrant is generally used only in post-menopausal women.
How Is Hormone Therapy Administered?
It is of great importance that hormone therapy is administered correctly for it to be effective. This method, which is applied in cancer treatment, should be carried out within a specific plan and under expert supervision. The method and duration of administration are determined specifically according to the patient's condition.
Duration and frequency of treatment
Hormone therapy is usually administered after surgery for early-stage breast cancer and is used to reduce the risk of cancer recurrence. The duration of treatment mostly varies between 5 and 10 years. This duration is determined by taking into account the person's specific condition and the risk of cancer recurrence.
In some cases, treatment can also be started before surgical intervention. Thus, it can be ensured that the tumor shrinks and less breast tissue is removed during surgery. Hormone therapy is an important treatment option that can be applied after chemotherapy or alone.
In advanced breast cancer, hormone therapy can be continued as long as it slows down or stops the growth of the cancer.
Oral medications
The most commonly used method in hormone therapy is oral medications. Tamoxifen and aromatase inhibitors (anastrozole, letrozole, exemestane) are used in the form of daily pills.
Tamoxifen is usually taken once a day and is used for 5-10 years in pre-menopausal women. In post-menopausal women, aromatase inhibitors are preferred. These drugs are also taken as one tablet per day and are usually used for 5 years.
Adherence to the treatment plan is very important. Regular use of medications directly affects the success of the treatment. If you are thinking about stopping treatment due to side effects, you should definitely talk to your doctor.
Injection and implant methods
Some hormone therapies can also be administered in the form of injections or implants. For example:
Fulvestrant (Faslodex): It is an injection administered to the hip area once a month. It is administered every two weeks for the first month, and once a month thereafter.
Zoladex (Goserelin): It is an implant the size of a grain of rice. It is injected under the skin in the lower abdomen every 28 days. There are also three-month forms.
LHRH analogs: Drugs such as goserelin and leuprolide are used to temporarily stop the ovaries from working. They are usually administered as an injection once a month or every three months.
Follow-up and check-ups during the treatment process
Regular follow-up and check-ups are essential during hormone therapy. These check-ups include:
Doctor visits: They are done every few months in the first years of treatment, and once a year thereafter.
Gynecological examinations: Women who use tamoxifen and have a uterus should have a gynecological examination once a year against the risk of uterine cancer.
Bone density tests: Bone density measurements should be performed, especially in patients using aromatase inhibitors, due to the risk of osteoporosis.
Blood tests: Hormone levels are checked regularly to evaluate the effectiveness of the treatment.
In addition, imaging methods such as mammography, ultrasound, or MRI are also used to monitor whether cancer symptoms have reappeared.
Side Effects and Considerations
Although hormone therapy for breast cancer is life-saving for many patients, it can also bring various side effects. Knowing these side effects and understanding how to manage them will help you have a more comfortable treatment process.
Common side effects
Some common side effects that may occur during hormone therapy are:
Hot flashes and sweating: It is frequently seen, especially in patients using tamoxifen and in menstruating women.
Joint and bone pain: It is more common in patients using aromatase inhibitors.
Fatigue and weakness: You may feel your energy drop in the middle of the day.
Mood changes: Depression, anxiety, or irritability may be experienced.
Weight changes: Weight gain may be seen due to metabolic changes.
Sexual problems: Complaints such as decreased libido and vaginal dryness may occur.
Long-term effects
Long-term hormone therapy can lead to some serious health problems. Among these:
In tamoxifen use:
Risk of uterine cancer: The risk of uterine lining cancer may increase with long-term use.
Blood clotting: Although rare, it can lead to serious problems such as pulmonary embolism.
Eye problems: Cataract formation may be seen.
Risk of stroke: It may increase with long-term use.
In aromatase inhibitors:
Osteoporosis: Decrease in bone density and risk of fracture.
Heart diseases: The risk of heart problems may increase in some patients.
Ways to cope with side effects
Various methods can be used to alleviate side effects:
For hot flashes:
Choosing light and breathable clothing.
Consuming cold drinks.
Trying acupuncture treatment, this method can reduce night sweats.
For joint pain:
Regular exercise can increase bone density.
Using calcium and vitamin D supplements.
For mental problems:
Getting psychological support or participating in support groups.
Using low-dose antidepressants if necessary by consulting your doctor.
How is the decision to continue treatment made?
The decision to continue hormone therapy is made by striking a balance between how much the side effects affect your quality of life and the risk of cancer recurrence. Regarding this:
Patients who decide to continue treatment usually:
Experience fear of cancer recurrence.
Trust the effectiveness of the drug.
Have developed various coping mechanisms.
Patients who decide to stop treatment:
Feel that their quality of life has dropped significantly.
Experience the dilemma of "surviving but without quality of life".
If you are having difficulty continuing treatment, you can discuss the following options with your doctor:
Reducing the drug dose.
Switching to a different drug.
Shortening the treatment duration.
However, regular doctor check-ups and close monitoring of side effects are of vital importance during the treatment process. Your treatment decision should depend not only on medical but also on your personal preferences.
In Summary, Hormone Therapy in Breast Cancer
As a result, hormone therapy in breast cancer is a highly effective treatment option, especially in hormone receptor-positive patients. Drugs such as tamoxifen and aromatase inhibitors reduce the risk of disease recurrence by stopping the growth of cancer cells. Thanks to this treatment, many patients can live a longer and healthier life.
It is of great importance that you do not skip your doctor check-ups during the treatment. When you encounter side effects, be sure to share them with your doctor. Alternative solutions can be found for hot flashes, joint pain, or other complaints. Also, you should not terminate the treatment on your own.
Undoubtedly, the hormone therapy process can be difficult. However, with regular check-ups and the right approach, you can get through this process more easily. Taking good care of yourself, eating a balanced diet, and exercising regularly will increase the effects of the treatment. Remember that every patient is unique and treatment responses can vary from person to person.
In light of all this information, being knowledgeable about hormone therapy will allow you to manage your treatment process more consciously. Do not hesitate to ask your questions by establishing open communication with your doctor. Adherence to treatment and regular follow-ups will help you achieve successful results in breast cancer treatment.
Frequently Asked Questions
We have gathered the answers to the questions you may have about breast cancer treatment. Below you can find the most curious topics and their answers.
Should I start breast cancer treatment immediately? Starting treatment on time is important, but instead of making a hasty decision, it is a priority to understand your diagnosis and treatment options well.
Is chemotherapy applied to everyone? No. Chemotherapy is a treatment option decided according to the type and spread of the tumor.
What is tamoxifen and what does it do? Tamoxifen is a drug that prevents the growth of hormone-fueled breast cancers. It works by preventing estrogen from binding to cancer cells.
What are the side effects seen during hormone therapy? Hot flashes, vaginal dryness, changes in the menstrual period, lack of sexual desire, nausea, mood changes, fatigue, and loss of appetite may be seen.
How is hormone therapy administered? It can be administered in three different ways: orally in the form of a pill, by injection into the arm, thigh, or hip, or by surgical removal of hormone-producing organs.
Does hormone therapy affect fertility? Yes, hormone therapy can lead to fertility problems. Especially if the ovaries have been removed by surgical operation or have received radiation therapy, infertility may occur.
Hormone therapy in breast cancer is an effective method used to slow down or stop the growth of hormone receptor-positive tumors. Drugs such as tamoxifen and aromatase inhibitors are commonly used.
