Sex hormones and cancer

Hormones are natural substances made by the glands of our hormone system. They are carried around our body in our bloodstream. They act as messengers to carry signals between one part of the body and another.

There are many different types of hormones. Each one controls the growth and activity of particular cells and organs.

What are the sex hormones?

The main sex hormones in women are oestrogen and progesterone. The ovaries produce most of these sex hormones.

In men, the main sex hormone is testosterone. Most of this is produced by the testes.

Small amounts of these sex hormones are also produced in other parts of the body, including the adrenal glands in men and women. This means that men have a small amount of oestrogen and progesterone. And women have small amounts of testosterone.

Hormones and cancer

Some cancers or cancer treatments can change the amount of hormones the body produces. Also, some cancer cells produce hormones that cause symptoms.

When cancer treatments change hormone levels, they usually lower the amount of a particular hormone. They can do this by blocking the action of hormones, or by reducing the amount of the hormone the body makes.  

Sometimes, treatments can stop the body making a particular hormone altogether. Treatment related changes in hormone levels may be temporary or permanent.

An example of this is chemotherapy. Some chemotherapy drugs can affect how the ovaries work. This can lower the amount of oestrogen. Or stop the production of oestrogen.

Treatments for prostate cancer and breast cancer are most likely to affect hormone levels in the body. But treatment for other types of cancer can affect them too.

The sex hormones are the type of hormone most commonly affected by cancer and its treatment. Changes in the level of sex hormones in the body can cause particular symptoms.

Sex hormones and what they do

Whether you are likely to have changes in sex hormone levels depends on the type of cancer and treatment you have. 

Oestrogen

Oestrogen is a female hormone. The ovaries make most of the oestrogen. The adrenal glands, which are small glands just above the kidneys, also make a small amount. Body fat also produces some oestrogen.

During puberty, oestrogen promotes female sexual development, which includes: 

• the start and control of periods (part of the menstrual cycle)
• development and growth of the breasts
• hair growth under the arms (axilla) and in the pubic area

Men produce some oestrogen, but much less than women. The testes and adrenal glands make a small amount. This helps sperm to mature and boosts sex drive (libido).

Progesterone

Progesterone is another female hormone. It’s made in the ovaries. A small amount is also made by the adrenal glands.

Progesterone helps to control the menstrual cycle. It also plays a part in breastfeeding and maintaining pregnancy. During pregnancy the placenta also produces progesterone. 

Testosterone

Testosterone is a male hormone. The testes make most of the testosterone. The adrenal glands also make a small amount of a similar male hormone, which the body changes into testosterone.
Men need testosterone to make sperm. It also helps to maintain muscle and contributes to sex drive. It plays a part in the sexual development of males during puberty, such as:

• a deeper voice
• growth of hair on the face, the armpits (axilla), chest, and tummy (abdomen)
• growth of muscle and bone, with an increase in height and weight 

In women, the ovaries and adrenal glands make small amounts of testosterone. This helps to maintain muscle and contributes to sex drive.

Sex hormone symptoms

You are likely to have symptoms if your cancer treatment lowers the level of sex hormones. Or treatment stops your body from making them.

Symptoms vary from person to person. They might be mild, but they can also be severe and need treatment. Some symptoms will only last for a few weeks or months, or while you are having your treatment. But they can also last for many months or years.

Symptoms of changes in sex hormone levels can include:

• hot flushes and sweats
• memory and concentration problems
• decreased or loss of interest in sex (loss of libido)
• mood changes
• tiredness
• difficulty sleeping
• aches and pains
• weight changes
• bone loss and weakening that could lead to a condition called osteoporosis
• heart problems due to increased cholesterol levels
• worry and anxiety
• headaches

Women might also have:

• vaginal dryness
• urinary problems
• changes to your periods (menstrual cycle)

Men might also have:

• lower sex drive and erection problems (impotence)
• breast swelling and tenderness
• muscle weakness

Coping with sex hormone symptoms

Find out about ways to help you cope with the symptoms you have. 

We also have an online forum called Cancer Chat, where you can share experiences.