What are the risk factors for endometrial cancer?

A risk factor is any factor that is associated with increasing someone’s chances of developing a certain condition, such as cancer. Some risk factors can be modified, such as lifestyle or environmental risk factors, and others cannot be modified, such as inherited factors or whether someone in the family has had cancer. 

Having 1 or more risk factors does not mean that a person will develop cancer. Many people have at least 1 risk factor but will never develop cancer, while others with cancer may have had no known risk factors. 

Even if a person with cancer has a risk factor, it is usually hard to know how much that risk factor contributed to the development of their disease. 

Endometrial cancer risk factors

Risk factors for developing endometrial cancer include:^[3] 

• family history – having close relatives with endometrial or colorectal cancer (Lynch syndrome, also known as hereditary non-polyposis colorectal cancer, or HNPCC), or PTEN hamartoma/Cowden syndrome (also see Genetic testing)
• mutations in certain genes (see Genetic testing)
• obesity 
• having more periods over your lifetime – that is, starting periods at a younger age and reaching menopause at an older age 
• not having children 
• taking menopausal hormone therapy (hormone replacement therapy) or tamoxifen 
• getting older – most women with endometrial cancer are diagnosed when they are between 65 and 69 years of age 
• eating an unbalanced diet, including foods that have a high fat content and/or glycaemic index (GI) 
• lack of physical exercise 
• having diabetes 
• having non-cancerous uterine conditions such as endometrial hyperplasia and polyps. 

There are several factors that decrease your risk for developing endometrial cancer, including: 

• drinking coffee 
• exercising 
• having children and breastfeeding 
• taking oral contraceptives (birth control pills). 

The document Risk factors for endometrial cancer: a review of the evidence 2019 provides detailed information about the evidence available for different risk factors. 

Genetic testing

People with faults in the following genes are predisposed to developing endometrial cancer: 

• MLH1 
• MSH2 
• MSH6 
• PMS2 
• PTEN. 

If you or a family member is found to have a fault in any of these genes, you may be referred to a clinical genetics service or familial cancer centre. These genes faults are also associated with developing Lynch syndrome (also known as hereditary non-polyposis colorectal cancer, or HNPCC) or PTEN hamartoma/Cowden syndrome. 

What you can do

There are things you can do to manage your risk of developing endometrial cancer. Factors that can be changed are called modifiable factors.

• Body weight – being overweight or obese is associated with an increased risk of endometrial cancer. Aim to keep to a healthy body weight (within a Body Mass Index (BMI) range of 18.5 to 25 kg/m²).
• Physical activity – being physically active is probably associated with a decreased risk of endometrial cancer. Doing 5 hours of moderate intensity physical activity a week has been shown to help protect against cancer and unhealthy weight gain.
• Breastfeeding – breastfeeding is probably associated with a decreased risk of endometrial cancer. The longer a woman breastfeeds, the lower her risk becomes.
• Menopausal hormone therapy (also referred to as Hormone replacement therapy (HRT)) – using certain types of menopausal hormone therapy (MHT) is associated with an increased risk of endometrial cancer. This includes MHT that only contains oestrogen, as well as the MHT medicine tibolone. The risk increases the longer you use these types of MHT. Having a discussion with your doctor is important in selecting the type of MHT. It is also important to review your needs regularly with your doctor if using MHT.
• Glycaemic load – eating a lot of foods that raise blood glucose levels is probably associated with increased risk of endometrial cancer. Aim to eat a balanced diet, rich in plant-based foods, including fruit, vegetables and other foods containing dietary fibre to reduce your risk of endometrial cancer and other cancers.

Links and support

If you are worried about your risk of developing endometrial cancer, see your doctor with any concerns.

For women with endometrial cancer

If you have been diagnosed with endometrial cancer, you might feel overwhelmed, scared, anxious or upset – these are all normal feelings. It’s very important to have support from family, friends, health professionals and/or other services to help you cope with cancer.

• Living with cancer has information about physical, emotional and practical issues during and after diagnosis and treatment.
• Cancer Australia’s resource Cancer – how are you travelling? provides information to help you understand the emotional and social impacts of cancer.
• The Cancer Council in your state or territory can give you general information about cancer, as well as information on resources and support groups in your local area. Call the Cancer Council Helpline from anywhere in Australia for the cost of a local call on 13 11 20.
• Other cancer support organisations can also help you and your loved ones deal with the challenges of cancer.