Most cases of cancer of the womb (uterus) - also called uterine cancer - arise from the endometrium, which is the inside lining of your womb. This is called endometrial cancer. The most common early symptom is abnormal vaginal bleeding. Most cases develop in women aged in their 50s or 60s. If endometrial cancer is diagnosed at an early stage, there is an excellent chance of a cure.
What is the womb (uterus)?
The uterus is in your lower tummy (abdomen) behind your bladder. The inside of your uterus is where a baby grows if you become pregnant. The inside lining of your uterus is called the endometrium. This builds up and is then shed each month as a period in women who have not yet gone through the menopause. The thick body of the uterus is called the myometrium and is made of specialised muscle tissue.
The lowest part of your uterus is the neck of the womb (cervix) which pushes just into the top part of your vagina. At the top of your uterus are the right and left Fallopian tubes which carry the eggs (released from your ovaries) to inside your uterus.
What is cancer?
Cancer is a disease of the cells in the body. The body is made up from millions of tiny cells. There are many different types of cell in the body and there are many different types of cancer which arise from different types of cell. What all types of cancer have in common is that the cancer cells are abnormal and multiply out of control.
A malignant tumour is a lump or growth of tissue made up from cancer cells which continue to multiply. Malignant tumours invade into nearby tissues and organs, which can cause damage.
Malignant tumours may also spread to other parts of the body. This happens if some cells break off from the first (primary) tumour and are carried in the bloodstream or lymph channels to other parts of the body. These small groups of cells may then multiply to form secondary tumours (metastases) in one or more parts of the body. These secondary tumours may then grow, invade and damage nearby tissues and spread again.
Some cancers are more serious than others. Some are more easily treated than others (particularly if diagnosed at an early stage). Some have a better outlook (prognosis) than others. In each case it is important to know exactly what type of cancer has developed, how large it has become, and whether it has spread. This will enable you to obtain reliable information on treatment options and outlook.
What is uterine cancer?
Most uterine cancers develop from cells in the endometrium. The endometrium is the inside lining of the womb (uterus) and this cancer is called endometrial cancer. Cancer developing from muscle cells in the myometrium (uterine sarcomas) are rare and are not dealt with further in this leaflet. Cancer of the cervix (cervical cancer) is quite different to uterine cancer and is dealt with in a separate leaflet.
The rest of this leaflet deals only with endometrial cancer of the uterus.
Each year about 8,600 women in the UK develop cancer of the inside lining of the womb (uterus), known as endometrial cancer. Most cases develop in women aged in their 50s and 60s. It rarely develops in women under the age of 50.
Type and grade of endometrial cancer
Most cases of endometrial cancer are called endometrioid adenocarcinomas. These arise from cells which form the glandular tissue in the lining of your endometrium. A sample of cancerous tissue can be looked at under the microscope. By looking at certain features of the cells the cancer can be graded.
- Grade 1 - is a low grade. The cells look reasonably similar to normal endometrial cells. The cancer cells are said to be well differentiated. The cancer cells tend to grow and multiply quite slowly and are not so aggressive.
- Grade 2 - is a middle grade.
- Grade 3 - the cells look very abnormal and are said to be poorly differentiated. The cancer cells tend to grow and multiply quite quickly and are more aggressive.
There are also some rarer types of endometrial cancer.
What causes endometrial cancer?
A cancerous tumour starts from one abnormal cell. The exact reason why a cell becomes cancerous is unclear. It is thought that something damages or alters certain genes in the cell. This makes the cell abnormal and multiply out of control. See separate leaflet called What Causes Cancer? for more details.
There are risk factors which are known to increase the risk of endometrial cancer developing. These include the following:
- Increased exposure to oestrogen. Oestrogen is the main female hormone. Before the menopause the changing level of oestrogen together with another hormone, progesterone, causes the endometrium to build up each month and then be shed as a period. It is thought that factors which lead to prolonged higher-than-usual levels of oestrogen, or increased levels of oestrogen not being balanced by progesterone, may somehow increase the risk of endometrial cells becoming cancerous. These include:
- If you have never had a baby. This is because your womb (uterus) has never had a rest from the rise of oestrogen that happens in the course of a normal monthly cycle.
- If you are overweight or obese. This is because fat cells make oestrogen.
- If you have certain rare oestrogen-producing tumours.
- If you have a late menopause (after the age of 52) or started periods at a young age. This is because you will have more monthly menstrual cycles.
- Endometrial hyperplasia. This is a non-cancerous (benign) condition where the endometrium builds up more than usual. It can cause heavy periods or irregular bleeding after the menopause. Most women with this condition do not develop cancer but the risk is slightly increased.
- Tamoxifen. This is a drug which is used in the treatment of breast cancer. The risk of developing endometrial cancer from tamoxifen is very small - about 1 in 500. However, the benefits of taking tamoxifen usually outweigh the risks.
- Diabetes. There is a small increased risk in women with diabetes.
- Polycystic ovary syndrome. There is a very slight increased risk in women with this condition.
- Genetic factors. 'Genetic' means that a condition is passed on through families through special codes inside cells called genes. Most cases of endometrial cancer are not due to genetic or inherited (hereditary) factors. However, in a small number of cases, a faulty gene (which can be inherited) may trigger the disease. This disorder is called hereditary nonpolyposis colon cancer (HNPCC).
Women who take the combined oral contraceptive pill actually have a lower risk of developing endometrial cancer.
What are the symptoms of endometrial cancer?
In most cases the first symptom of cancer of the inside lining of the womb (uterus) - known as endometrial cancer - is abnormal vaginal bleeding such as:
- Vaginal bleeding past the menopause. This can range from spotting to more heavy bleeds. This is the most common symptom of endometrial cancer.
- Bleeding after having sex (postcoital bleeding).
- Bleeding between normal periods (intermenstrual bleeding) in women who have not gone through the menopause.
Early symptoms that occur in some cases are:
- Pain during or after having sex.
- Vaginal discharge.
- Pain in your lower tummy (abdomen).
All the above symptoms can be caused by various other common conditions. However, if you develop any of these symptoms, you should see your doctor.
Note: a cervical screening test does not screen for endometrial cancer.
In time, if the cancer spreads to other parts of the body, various other symptoms can develop.
How is endometrial cancer diagnosed and assessed?
To confirm the diagnosis
A doctor will usually do a vaginal examination if you have symptoms which may be due to cancer of the inside lining of the womb (uterus) - known as endometrial cancer. He or she may feel an enlarged uterus. It is likely you will need to have a further test to confirm the diagnosis - usually one of the following:
- Ultrasound scan of your uterus. This is usually the first test that is done. An ultrasound scan is a safe and painless test which uses sound waves to create images of organs and structures inside your body. It is most commonly used in pregnant women. The probe of the scanner may be placed on your tummy (abdomen) to scan the uterus. Sometimes a small probe is also placed inside your vagina to scan your uterus from this angle.
- Endometrial sampling. In this procedure, a thin tube is passed into your uterus. By using very gentle suction, small samples of your endometrium can often be obtained. This is done in the outpatient clinic, without an anaesthetic. The sample (biopsy) is looked at under the microscope to look for any abnormal cancer cells.
- Hysteroscopy. In this procedure, a doctor uses a hysteroscope, which is a thin telescope that is passed through the neck of your womb (cervix) into your uterus. The doctor can see the lining of your uterus and take samples of any abnormal-looking areas. This can also be done without an anaesthetic.
Assessing the extent and spread
If endometrial cancer is confirmed then further tests may be advised to assess if the cancer has spread. For example, a CT scan, an MRI scan, a chest X-ray, blood tests, an examination under anaesthetic of the uterus, bladder or rectum, or other tests. This assessment is called staging of the cancer. The aim of staging is to find out:
- How much the tumour has grown and whether it has grown to other nearby structures such as the cervix, bladder or rectum.
- Whether the cancer has spread to local lymph glands (nodes).
- Whether the cancer has spread to other areas of the body (metastasised).
Finding out the stage of the cancer helps doctors to advise on the best treatment options. It also gives a reasonable indication of outlook (prognosis). See separate leaflet called Staging and Grading Cancer for more details.
What are the treatment options for endometrial cancer?
Surgery is the main treatment for cancer of the inside lining of the womb (uterus) - known as endometrial cancer. Radiotherapy or chemotherapy are also used in some circumstances. The treatment advised for each case depends on various factors such as the stage of the cancer (how large the cancer is and whether it has spread) and your general health.
You should have a full discussion with a specialist who knows your case. He or she will be able to give the pros and cons, likely success rate, possible side-effects and other details about the various possible treatment options for your type of cancer. You should also discuss with your specialist the aims of treatment. For example:
- In some cases, treatment aims to cure the cancer. Most cases of endometrial cancer are diagnosed at an early stage. There is a good chance of a cure if it is treated in the early stages. (Doctors tend to use the word remission rather than the word cured. Remission means there is no evidence of cancer following treatment. If you are in remission, you may be cured. However, in some cases a cancer returns months or years later. This is why doctors are sometimes reluctant to use the word cured.)
- In some cases, treatment aims to control the cancer. If a cure is not realistic, with treatment it is often possible to limit the growth or spread of the cancer so that it progresses less rapidly. This may keep you free of symptoms for some time.
- In some cases, treatment aims to ease symptoms. For example, if a cancer is advanced then you may require treatments such as painkillers or other treatments to help keep you free of pain or other symptoms. Some treatments may be used to reduce the size of a cancer, which may ease symptoms such as pain.
An operation to remove your uterus (hysterectomy) and ovaries is a common treatment. It is common for your Fallopian tubes and both ovaries to be removed as well. Many operations are now performed by a keyhole procedure (laparoscopically). If the cancer is at an early stage and has not spread then surgery alone can be curative.
If the cancer has spread to other parts of the body, surgery may still be advised, often in addition to other treatments. Even if the cancer is advanced and a cure is not possible, some surgical techniques may still have a place to ease symptoms - for example, to relieve a blockage of the bowel or urinary tract which has been caused by the spread of the cancer.
Radiotherapy is a treatment which uses high-energy beams of radiation which are focused on cancerous tissue. This kills cancer cells or stops cancer cells from multiplying. Radiotherapy alone can be curative for early-stage endometrial cancer and may be an alternative to surgery. In some cases radiotherapy may be advised in addition to surgery.
Even if the cancer is advanced and a cure is not possible, radiotherapy may still have a place to ease symptoms. For example, radiotherapy may be used to shrink secondary tumours which have developed in other parts of the body and are causing pain.
Chemotherapy is a treatment of cancer using anti-cancer drugs. They kill cancer cells, or stop them from multiplying. Chemotherapy is not a standard treatment for endometrial cancer but may be given in certain situations (usually in addition to radiotherapy or surgery).
Treatment with progesterone is used in some types of endometrial cancer. It is generally not used in the initial treatments but may be considered if the cancer spreads or comes back after those treatments.
What is the outlook (prognosis)?
There is an excellent chance of a cure if cancer of the inside lining of the womb (uterus) - known as endometrial cancer - is diagnosed and treated when the disease is at an early stage. This is when the cancer is confined to the uterus and has not spread. Many cases are diagnosed at an early stage because abnormal vaginal bleeding often develops at an early stage of the disease and alerts women (and their doctors) to the possibility of cancer. For women who are diagnosed when the cancer has already spread, a cure is less likely but still possible. Even if a cure is not possible, treatment can often slow down the progression of the cancer.
The treatment of cancer is a developing area of medicine. New treatments continue to be developed and the information on outlook above is very general. The specialist who knows your case can give more accurate information about your particular outlook and how well your type and stage of cancer are likely to respond to treatment.
Dr Tim Kenny
Dr Louise Newson
Dr John Cox