How Are Estrogens Used for Prostate Cancer?

Estrogens are commonly known as female sex hormones that regulate the reproductive system, as well as growth and development in females. Estrogens are used for a variety of purposes including birth control, hormone replacement therapy, and can be used to treat prostate cancer. Using estrogens to treat prostate cancer is often used after many other treatment options have failed. The use of estrogens as a first-line defense against prostate cancer has decreased due to the advent of newer, more effective treatments including non-steroidal anti-androgens. Estrogens are typically administered orally. Individuals taking estrogens should be monitored for changes in liver functioning and the development of blood clots in the legs, lungs, or arteries.

What are the ingredients in estrogen therapies?

The active ingredient in estrogen therapies can vary based on the treatment and its brand, however, common active ingredients include synthetic (man-made) estrogens such as ethinyl estradiol.

How does treatment with estrogen work?

Prostate cancer tumors are often fueled to grow by androgens, including testosterone. Decreasing the body’s production of testosterone can potentially halt tumor growth. When a male is treated with estrogen-containing medications, it can prompt his body to stop making testosterone. This decrease in the important androgen could starve off tumor cells, limiting their ability to grow and spread.

What are the possible side effects of taking an estrogen therapy?

Multiple clinical trials across decades have evaluated the safety and effectiveness of estrogen therapies. When taking estrogens for prostate cancer, possible side effects of certain therapies may include nausea, vomiting, swelling of the limbs, sexual dysfunction, enlargement of the breasts, decreased sex drive, headache, hair thinning, or skin rashes. These are not all the possible side effects of estrogen therapies. Talk to your doctor about what to expect or if you experience any changes that concern you during treatment with estrogen therapies.

Things to note about taking estrogen therapies

Several rare but more serious side effects can accompany taking estrogen therapies including changes in liver function. Alert your provider immediately if you notice yellowing of your skin or the whites of your eyes, as well as any abnormal swelling, pain, or tenderness in your abdomen. Additionally, treatment with estrogens can increase your risk of blood clots. These clots can lead to serious problems such as stroke or heart attack. Alert your provider immediately if you notice any of the following symptoms:

• Stabbing pains, swelling, warmth, or tenderness of arm or leg
• Coughing up blood
• Painful breathing or coughing
• Sudden chest pain
• Sudden difficulty breathing
• Migraine headaches with or without vision problems

You may also experience mood changes while on estrogen therapies. Alert your provider immediately if these are significant or life-threatening. Also, changes in skin coloration may happen while taking estrogens. It is important to practice appropriate sun safety and wear appropriate sunscreen, especially on the face and neck when outside.

Before starting estrogen therapy talk to your provider if you:

• Have high blood pressure, high cholesterol or diabetes
• Have a history of blood clots
• Are a smoker
• Have kidney, liver, or gallbladder problems
• Have a heart condition or any problems with your heart or blood circulation
• Have a history of stroke, migraines, chest pain, seizures, or asthma
• Have hearing loss or wear contact lenses
• Are scheduled to have surgery
• Have any other medical conditions or allergies
• Are currently taking any other medications (prescription and over-the-counter), vitamins, or herbal supplements

You should also contact your provider if you notice any signs of an allergic reaction to the medication, including chest pain or difficulty breathing.

Receiving estrogen therapies

Estrogen therapies are administered orally and vary in dosage based on the condition being treated. Your provider will determine the appropriate dosage and administration schedule for you, as well as the appropriate dosage and administration of any other medications taken with estrogen therapies. It is important to take your estrogen therapy exactly as instructed, and not to stop taking an estrogen therapy or any accompanying medications on your own. Patients should talk to their doctor if they have any questions, or if they have questions regarding their estrogen therapy regimen.

Consult your provider on what to do when you miss a dose of your estrogen therapy. For some therapies, you may be able to make up the missed dose within the same day, while other therapies require you to wait until the following day to continue the treatment as normal (and not make up the missed dose). Your provider will instruct you on what method is correct for your specific medication. If you take too much of your estrogen therapy, seek medical attention immediately.^1-2