Hormones are natural substances made by the glands of our hormone system and released into the blood. 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.
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 particular hormones. 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.
Treatments for breast cancer and prostate 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 cancer
Whether you are likely to have changes in sex hormone levels depends on the type of cancer and treatment you have.
Sex hormones include oestrogen, progesterone and testosterone.
Oestrogen is a female hormone. The ovaries make most of the oestrogen a woman needs. The adrenal glands also make a small amount. These are small glands just above the kidneys. Body fat also produces some oestrogen.
During puberty, oestrogen promotes the sexual development of girls, including breast growth. Oestrogen also helps to control periods (the menstrual cycle) and the release of eggs.
Men produce some oestrogen, but much less than women. In men, the testes and adrenal glands make a small amount, which helps sperm to mature and boosts sex drive (libido).
Progesterone is another female hormone made by the ovaries. During pregnancy the placenta also makes progesterone.
Progesterone helps to control the menstrual cycle. It also plays a part in breastfeeding and maintaining pregnancy.
Testosterone is a male hormone. The testes make most of the testosterone a man needs. 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 boys during puberty, such as:
- a deeper voice
- growth of facial hair
- muscle growth
In women the ovaries and adrenal glands make small amounts of testosterone which helps to maintain muscle and contributes to sex drive.
Sex hormone symptoms
If cancer treatment lowers the level of sex hormones or stops your body making them, you are likely to have some symptoms.
Symptoms vary from person to person. Although they can be mild, they can also be severe and need treatment. Some symptoms will only last for a few weeks or months, or while you are having the 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
- difficulty sleeping
- aches and pains
- weight changes
- bone loss
- heart problems due to increased cholesterol levels
Women might also have:
- vaginal dryness
- urinary problems
Men might also have:
- lower sex drive and erection problems (impotence)
- breast swelling and tenderness
- muscle weakness