Cancer of Unknown Primary: Hormone Therapy

What is hormone therapy?

Natural sex hormones in the body can help some cancers grow. Hormone therapy is used to change the way these hormones work. It can lower hormone levels or keep them from working. Hormone therapy may be used to help stop a tumor from growing or ease symptoms caused by the tumor.

When might hormone therapy be used for cancer of unknown primary?

If your healthcare provider thinks that your cancer of unknown primary (CUP) may be breast or prostate cancer, he or she may suggest hormone therapy. This treatment is sometimes used to stop the hormones in your body from allowing cancer cells to grow.

This can be done in different ways. For instance, you may have surgery that takes out certain organs that make hormones. Or you may take medicines that change the way hormones work.  Another option may be using radiation to damage organs that make hormones. For instance, radiation to the ovaries can stop estrogen from being made in women.

How is hormone therapy given for cancer of unknown primary?

Hormone therapy is often given as shots or pills. Sometimes surgery or radiation is used to keep certain organs from making hormones. These include the testicles or ovaries.

Some medicines limit the production of the female hormone estrogen. This may help slow the growth of breast tumors. These medicines include:

• Exemestane

• Anastrazole

For prostate cancer, medicines may either lower the testosterone level or prevent cancer cells from being able to use it to fuel tumor growth. These medicines include:

• Leuprolide

• Goserelin

• Antiandrogens, such as flutamide and bicalutamide

Your healthcare provider may test your cancer to see if hormone therapy might work.

Potential side effects from hormone therapy for cancer of unknown primary

Hormone therapy may cause side effects. These depend on the type of treatment you get or medicines you receive. Common side effects include the following:

• Hot flashes

• Vaginal dryness or discharge in women

• Low red blood cell levels (anemia)

• Trouble thinking and remembering

• Weight gain

• Nausea

• Tiredness and fatigue

• Depression

• Muscle, bone, or joint pain and stiffness

• Weak bones (osteoporosis)

• Loss of interest in sex

Tell your healthcare provider about any side effects you have. There are often ways to ease them. This can help you feel better.

Working with your healthcare provider

It's important to know which medicines you're taking. Write your medicines down, and ask your healthcare team how they work. You should also ask about what side effects they may cause. Ask your healthcare team about what signs to look for and when to call them.

It may be helpful to keep a journal of your side effects. Write down physical, mental, and emotional changes. A written list will make it easier for you to remember your questions when you go to your checkups. It will also make it easier for you to work with your healthcare team to manage your side effects.