Hormones are natural substances made by glands in our bodies. They are carried around our body in our bloodstream and act as messengers between one part of our body to another. Some examples of hormones include: estrogen, testosterone, insulin, thyroid hormone, cortisol, and epinephrine. Hormones are responsible for many functions in our body, including the growth and activity of certain cells and organs. The endocrine system is the network of glands that make hormones. Researchers have found that some cancers are “fueled” by hormones, and may depend on them to grow.

In these cases, blocking the action of these hormones could possibly stop the cancer from growing. There are possibilities wherein this can happen.

Block the hormones from acting:-

Cells have “receptors” on their surface that certain hormones connect to and trigger activity inside the cells. By blocking the receptor with another compound, the hormone is not able to connect to its receptor. So if the hormone’s normal “parking spot” on the cell is already taken, the hormone cannot attach to and activate the cell.

Prevent the body from producing the hormone: –

This can be done with medication to block production of the hormone, or with surgery to remove the organ that produces it. For example, estrogen production can be significantly decreased by surgically removing the ovaries.

Eliminate the hormone receptors on cells or change their shape: –

This makes it impossible for the hormone to properly attach itself to the cell receptor and to activate it, essentially making the hormone unable to function. Hormone therapy is a treatment that uses medicines to block or lower the amount of hormones in the body to slow down or stop the growth of cancer. 

Cancers that can be hormone sensitive include:

• Breast cancer
• Prostate cancer
• Ovarian cancer
• Womb cancer (also called uterine or endometrial cancer)

Hormone therapy that is used to treat certain cancers should not be confused with hormone replacement therapy. Hormone therapy is used to block hormones or their actions, whereas hormone replacement therapy, which is not a cancer treatment, usually refers to giving hormones to replace the ones the body no longer makes in order to treat menopause-related symptoms.

Hormone therapy is most often used to treat breast and prostate cancers, where its role is well established through numerous clinical trials. Meanwhile, research is ongoing to study the potential use of hormonal therapy in treating other cancer types. Hormone therapy can be given in a few ways:

Oral medication – some therapies are taken by mouth.

Injection – some therapies are given by an injection under the skin (subcutaneous) or in the muscle (intramuscular).

Surgical intervention – for example, removal of the ovaries in women, or testicles in men, that results in decreased production of certain hormones.

Many patients think of hormone therapy as being “less potent” than chemotherapy, but it can be just as effective in certain breast and prostate cancers.

Hormone therapy is considered a “systemic” therapy, meaning that it travels throughout the body. Surgery and radiation therapy are considered “local” treatments.

Side effects:-

The side effects are caused by the lack of whatever hormone is being blocked or inactivated.  For women, these effects are similar to those experienced with menopause, which is the body’s natural decline in estrogen production with age. Side effects can include: hot flashes, night sweats, weight gain, vaginal dryness, and headache. This also includes:

• Nausea
• Hair loss or thinning
• Muscle aches and joint pain
• Blood clots and increased risk of uterine/endometrial cancer.
• In men, the side effects can include hot flashes, tiredness, breast tenderness or enlargement
• Loss of sex drive

This decrease in the body’s natural hormones can put men and women at higher risk for developing osteoporosis. Bisphosphonate therapy may be used to counteract this side effect. This may include increasing calcium and vitamin D intake through diet or supplements, participating in weight-bearing exercise and avoiding tobacco and alcohol use.