Most cases of uterine cancer (cancer of the uterus) arise from the inside lining of the uterus (the endometrium). This is called endometrial cancer. About 4500 women in the UK develop endometrial cancer each year. Most cases develop in women in their 50s and 60s. It rarely develops in women under the age of 50.
The uterus (womb) is in the lower abdomen behind the bladder. The inside of the uterus is where a baby grows if you become pregnant. The inside lining of the 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 the uterus is called the cervix which pushes just into the top part of the vagina. At the top of the uterus are the right and left fallopian tubes which carry the eggs released from the ovaries to the inside of the uterus.
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 the endometrium. A sample of cancer tissue can be looked at under the microscope. By looking at certain features of the cells the cancer can be ‘graded’.
- Grade 1 (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.
Causes of Endometrial Cancer
A cancerous tumour starts from one abnormal endometrial 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 cells abnormal and multiply ‘out of control’. 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, cause 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. (Your uterus has never had a ‘rest’ from the cyclical rise of oestrogen every month.)
- If you are overweight or obese. (Fat cells make a certain amount of 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.
- Endometrial hyperplasia. This is a benign (non cancerous) 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.
- Diet. There are much fewer cases of endometrial cancer in certain eastern countries and dietary factors may be the reason. A western diet high in fat may be a contributing factor.
- Genetic factors. Most cases are not due to genetic or 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 have a lower risk of developing endometrial cancer.
Symptoms of Endometrial Cancer
In most cases the first symptom to develop 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 (post coital 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, and pain in the lower abdomen.
All of 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.
For further information on Endometrial Cancer, please follow the link below: