Hormone Therapy For Cancer - Risk Factors, and Types

Introduction:

Hormones are peptides or steroids that are produced by tissue and transferred from 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 help block or lower the number of hormones in the body, which ultimately helps to slow down or stop the growth or progression of cancer.

Which Cancer Types Are Amenable to Treatment With Hormone Therapy?

Hormonal levels play a role in regulating various cancer types. Hormone therapy is frequently utilized in the treatment of the following common cancers:

• Breast Cancer: Breast cancer often relies on estrogen or progesterone hormones for growth in numerous instances. Tumors possessing receptors receptive to these hormones are termed "hormone receptor-positive." Suppressing these hormones or reducing estrogen production in the body can aid in preventing recurrence or managing metastatic cancer.

• Prostate Cancer: Prostate cancer typically progresses due to the influence of hormones known as androgens, with testosterone being the predominant androgen. Decreasing androgen levels can mitigate the pace of prostate cancer growth.

• Thyroid Cancer: For individuals with thyroid cancer undergoing surgical treatment, thyroid hormone therapy is often necessary. This therapy supplements the body's hormone levels and might impede the growth of any remaining cancer cells.

Hormone therapy may also be advised for less common types of cancers. For instance:

• Adrenal Cancer: Excessive hormone production by an adrenal gland; the tumor may necessitate various medications to regulate hormone levels before, during, or after other treatments.

• Neuroendocrine Tumors: Hormone therapies could potentially decelerate the progression of neuroendocrine tumors (NETs) and manage symptoms resulting from hormone secretion by the tumor.

• Pituitary Gland Tumor: Tumors in the pituitary gland might disrupt hormone production essential for bodily functions, potentially requiring hormone therapy to restore hormone balance.

• Uterine Cancer: Certain types of uterine cancer cells sensitive to estrogen and progesterone may experience slowed growth through hormone therapy.

In What Manner Is Hormone Therapy Combined With Other Cancer Treatments?

In conjunction with other treatments, hormone therapy has the potential to achieve the following:

• Reduce the size of a tumor before surgery or radiation therapy, which is referred to as neoadjuvant therapy.

• Decrease the likelihood of cancer recurrence following the primary treatment, known as adjuvant therapy.

• Eliminate cancer cells that have recurred or metastasized to other parts of the body.

What Are the Types of Hormone Therapy?

The decision on hormone therapy is made by the specialist after the 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. The 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.

The 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) or those women who have had their menopause ( post-menopausal).

It is also helpful in chemoprevention. 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 control hormone production in 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 is one such medicine used for breast cancer.

4. Fulvestrant:

Fulvestrant is a medicine that inhibits estrogen from reaching cancer cells. This happens because of the blockage of estrogen receptors, thus limiting the number of receptors available for cancer cells. This medicine can be used in combination with other cancer drugs.

The 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 testosterone produced 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, help 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. The 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.

What Are the Side Effects of Hormone Therapy?

As hormone therapy hinders the body's hormone production or alters hormone behavior, it can lead to undesirable side effects. The specific side effects experienced vary based on the type of hormone therapy administered and individual responses. Notably, people may respond differently to identical treatments, resulting in varying side effects. Additionally, certain side effects may differ depending on whether the individual is male or female.

Men undergoing hormone therapy for prostate cancer commonly experience the following side effects:

• Hot flashes.

• Fatigue.

• Decreased libido or erectile dysfunction.

• Breast enlargement and tenderness.

• Osteoporosis.

• Nausea.

• Diarrhea.

Women undergoing hormone therapy for breast cancer commonly experience the following side effects:

• Hot flashes.

• Fatigue.

• Vaginal dryness.

• Mood swings.

• Alterations in menstrual cycles for premenopausal women.

• Nausea.

• Decreased libido.

Conclusion:

Hormone therapy for cancers is useful in certain types of cancers. Hormone therapy plays a pivotal role in cancer treatment, targeting hormone-sensitive cancers such as breast, prostate, thyroid, and uterine cancers. By modulating hormone levels, it aims to impede cancer growth and recurrence, enhancing treatment outcomes and patient prognosis. Consult a physician or specialist online to learn more about this therapy.