Introduction:
Hormones are peptides or a steroid that is produced by tissue and transferred to the bloodstream to the target organs for their maturation. They are helpful in the growth and development of an individual. The endocrine system is a network of all the glands that produce hormones. Hormone therapy is a treatment done using certain medicines that helps in blockage or lowering the number of hormones in the body which ultimately helps to slow down or stop the growth or progression of cancer.
What Are Hormone-Dependent Cancers?
Certain cancers are dependent on hormones or hormone-producing cells. Hormones also play a major role in the progression of cancer. Some of the hormone-dependent cancers are breast, prostate, womb cancer (also called uterine or endometrial cancer), and ovaries.
What Are the Risk Factors?
Certain risk factors make the person prone to develop such cancers, which are as follows:
1. Risk factors for breast cancer:
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Early initiation of menstruation.
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Late Menopause.
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History of hormone replacement therapy.
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A diet consisting of high fat.
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Usage of oral contraceptive pills.
2. Risk factors for prostate cancer:
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Certain ethnic groups or races.
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Androgen receptor.
How Does Hormone Therapy Work?
A few cancers, as mentioned above, use hormones to develop or grow. It indicates that the cancer is either hormone-sensitive or dependent on the hormone. The hormone therapy functions opposite as it uses certain medicines to limit or stop the excess hormone production in the body and helps in slowing down the growth of cancer. But it is not guaranteed to work in all cancers.
What Are the Types of Hormone Therapy?
The decision of hormone therapy is made by your specialist after your complete examination and assessment. It is dependent on various factors like the type of cancer, a person's medical history, etc.
The major two hormones seen in females are estrogen and progesterone, which are known to affect some breast cancers. They are called estrogen receptor-positive (ER+) or progesterone receptor-positive (PR+), or sometimes both. The hormone therapy for breast cancer is aimed at stopping these hormones from reaching the breast cancer cells. Your physician may decide to go ahead with more than one single type of hormone therapy to treat the breast cancer patient. If started in the early stages of breast cancer, it helps in preventing the reversal of breast cancer.
Following Medications Can Be Used for Breast Cancer:
1. Tamoxifen:
Tamoxifen's mechanism of action is to block the estrogen receptors. It is one of the most commonly used hormone therapies for managing breast cancer. It is indicated in women who are either having periods (premenopausal) and those women who have had their menopause ( post-menopausal).
It is also helpful in chemoprevention. In it, hormone therapy (Tamoxifen or Raloxifene) is prescribed to patients who are at high risk of developing breast cancer. Although, it is important to know that it is not indicated for all cancers.
2. Aromatase Inhibitors:
This is indicated in women who have had menopause. Ovaries stop the production of estrogen after menopause. But, the body is capable of transforming other hormones, called androgens, into estrogen, although in small amounts. Aromatase is the enzyme that helps in performing this transformation. Aromatase inhibitors act by blocking aromatase, and thus, the transformation is stopped.
Various types of aromatase inhibitors are Exemestane, Anastrozole, and Letrozole.
3. Luteinizing Hormone-Releasing Hormone (LHRH) Agonists (LH Blockers):
The pituitary gland is situated in the brain, which produces the luteinizing hormone (LH). This hormone helps in controlling the hormone production from the ovaries. LH blockers are medicines that help in stopping the production of luteinizing hormones. Their mechanism of action is blocking the signal sent from the pituitary gland to the ovaries. Hence, the ovaries stop producing the hormones estrogen or progesterone.
This is indicated in females who have not attained menopause. Goserelin (Zoladex) is one such medicine used for breast cancer.
4. Fulvestrant:
Fulvestrant is a medicine that inhibits estrogen from reaching cancer cells. This happens by blockage of estrogen receptors and thus, limiting the number of receptors available for cancer cells. This medicine can be used in combination with other cancer drugs.
Following Medications Can Be Used for Prostate Cancer:
The growth of prostate cancer is dependent on testosterone levels. Hormone therapy for this cancer helps in limiting the testosterone levels in the body. This treatment can prevent the regrowth of prostate cancer if given in the early stages, and for large tumors, it can help in shrinking them.
1. Luteinising Hormone-Releasing Hormone (LHRH) Agonists (LH Blockers):
The luteinizing hormone (LH) produced by pituitary glands also controls the amount of production of testosterone by the testicles. LH blockers will limit the production of luteinizing hormone by preventing the signal from the pituitary gland from reaching the testicles. Hence, the testicles are not able to produce testosterone.
Certain drugs used in prostate cancer are Goserelin, Leuprorelin, and Triptorelin.
2. Anti-Androgens:
Prostate cancer cells have certain areas that are called receptors. Testosterone encourages the growth of these cells by getting attached to these receptors. Anti-androgen drugs act contrary to it by getting attached to these receptors and thus, helps in stopping the testosterone from reaching the cancer cells of the prostate.
Bicalutamide, Cyproterone acetate, and Flutamide are some of the anti-androgens used for hormone therapy.
3. Gonadotropin-Releasing Hormone (GnRH) Blocker:
Gonadotropin-releasing hormone (GnRH) blockers help in blocking the messages from the hypothalamus, which is situated in the brain. Hypothalamus instructs the pituitary gland to produce the luteinizing hormone. The luteinizing hormone then sends a message to the testicles to produce testosterone. Hence, blocking GnRH ultimately stops the testicles from producing testosterone. Degarelix is a GnRH blocker used for hormone therapy.
Other Hormone Therapies:
There are some recent additions to hormonal treatments for prostate cancer. They are as follows:
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Enzalutamide.
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Darolutamide.
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Abiraterone.
Hormone Therapy for Womb Cancer:
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The female hormones estrogen and progesterone are the ones that affect the growth and functioning of the cells lining the womb. Progesterone is used by physicians to shrink larger womb cancers or in treating womb cancers that have relapsed.
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Medroxyprogesterone acetate and Megestrol are some of the Progesterone varieties used for this therapy.
Conclusion:
Hormone therapy for cancers is useful in certain types of cancers. Consult a physician or specialist online to know more about this therapy.
