Cancers of the uterus (womb) usually begin in the cells that make up the lining of the uterus (endometrium).
Cancers of the uterus are often referred to as endometrial cancer because this term helps to distinguish it from other cancers that can affect the female reproductive system, such as cervical or ovarian cancer.
The uterus and the endometrium
The uterus, commonly known as the womb, is the part of the female reproductive system where a fertilised egg develops into a baby during pregnancy.
The uterus is lined by a layer of cells called the endometrium. The endometrium provides a healthy environment for a fertilised egg, and the cells that make up the endometrium are regularly discarded during a woman’s monthly period, then replaced by new cells.
Types of endometrial cancer
There are two main types of endometrial cancer:
- Type 1 endometrial cancer: a slow-growing cancer, thought to be linked to the female hormone oestrogen.
- Type 2 endometrial cancer: a more aggressive, faster-growing form of cancer that does not appear to have any connection to oestrogen.
Type 1 endometrial cancer is the most common type, accounting for an estimated 80% of cases. Type 2 accounts for around 10% of cases.
As well as types 1 and 2 endometrial cancer, there are a number of rarer types of cancers of the uterus (see Useful links for more information about these).
How common is endometrial cancer?
Endometrial cancer is the most commonly occurring cancer of the female reproductive system. It is the fourth most common cancer that affects women, after breast cancer, lung cancer and cancer of the colon and rectum.
In 2006 in England and Wales, 6,056 new cases of endometrial cancer were registered and there were 1,039 deaths from endometrial cancer.
About 75% of cases of endometrial cancer are in women who have had the menopause (post-menopausal), mostly in women aged 60 to 69.
Endometrial cancer is thought to be more common in post-menopausal women because of the changes in hormone levels that happen during the menopause. They may make a woman more susceptible to endometrial cancer.
Obesity is a major risk factor for endometrial cancer. The number of cases of endometrial cancer is 10 times higher in Europe and north America than in the developing world. This can be explained by the corresponding high rates of obesity in Europe and north America.
Outlook
The outlook for type 1 endometrial cancer is usually very good. This is because this type of cancer is usually detected in its earliest stages, when a complete cure is usually possible.
An estimated 85% of women with early-stage endometrial cancer will survive for five years or more after the diagnosis, and most of them will achieve a complete cure.
Due to its more aggressive nature, the prognosis for type 2 endometrial cancer is less favourable as it's usually at an advanced stage by the time it's detected.
Only 45% of women with advanced endometrial cancer, and 25% of women with end-stage endometrial cancer, will survive for five years or more, and a complete cure is often not possible in these circumstances.
Endometrial cancer can be treated by surgically removing the womb (hysterectomy). Radiotherapy and chemotherapy is also sometimes used after surgery to reduce the risk of the cancer returning.
