A risk factor is anything that may increase your chance of having a disease. Risk factors for a certain type of cancer might include smoking, diet, family history, or many other things. The exact cause of someone's cancer may not be known. However, risk factors can make it more likely for a person to have cancer. It's normal to wonder why your cancer started.

Things you should know about risk factors for cancer:

• Risk factors can increase a person's risk, but they don't always cause the disease.
• Some people with one or more risk factors never get cancer. Other people with cancer have no risk factors.
• Some risk factors are very well known. But there's ongoing research about risk factors for many types of cancer.

Some risk factors, like age or family history, may not be in your control. But others may be things you can change. Knowing the risk factors can help you make choices that might help lower your risk. For instance, if an unhealthy diet is a risk factor, you may choose to eat healthy foods. If excess weight is a risk factor, your doctor may check your weight or help you lose weight.

Risk factors for endometrial cancer include:

• Type 2 diabetes.
• Diet high in animal fats.
• Not being physically active.
• Family history of endometrial cancer in a first-degree relative (parent, sibling, or child).
• Family history of colon cancer (hereditary nonpolyposis colon cancer or Lynch syndrome).
• Personal history of breast cancer.
• Personal history of ovarian cancer.
• Personal history of colon cancer.
• Past radiation therapy to the pelvis.
• Personal history of atypical endometrial hyperplasia.
• Older age.

Most of the risk factors linked to endometrial cancer come from too much exposure to the hormone estrogen. Estrogen and progesterone are the two main types of female hormones. The balance between these two hormones changes every month during your menstrual cycle. The hormones need to be in the right balance for your uterus to be healthy. Risk factors that can affect this hormone balance and can increase your risk for endometrial cancer include:

• Obesity.
• Late menopause.
• Starting monthly periods before age 12.
• Inability to get pregnant (infertility).
• Not giving birth to any children.
• Taking tamoxifen to prevent or treat breast cancer.
• Use of estrogen replacement therapy (ERT) to treat menopause symptoms.
• Personal history of polyendocrine metabolic ovarian syndrome (PMOS).
• Personal history of a type of ovarian tumor that produces estrogen, such as granulosa cell tumor.

Talk with your doctor about your risk factors for endometrial cancer and what you can do about them. For instance, you may be able to lower your risk in areas you can control, such as diet and exercise. In fact, you can make some general lifestyle changes to reduce your endometrial cancer risk:

• Eat healthy foods and stay at a weight that is healthy for you. Limit the fat in your diet. Eat a moderate amount of a variety of foods. Get regular physical activity. If you have diabetes, work with your care team to manage your condition. Your plan may include diet, exercise, and medicine. These steps will all help keep your weight within a healthy range.
• Monitor and treat endometrial hyperplasia. If you have pre-cancer changes of the endometrium, talk to your doctor. You may need screening tests to check on the changes. Or you may need treatment.
• Review your hormone therapy strategy. If you're going through menopause and use estrogen therapy to help deal with the symptoms, use the lowest dose possible for the shortest amount of time. Talk with your doctor about taking progesterone along with estrogen. This is called combination therapy. Using just estrogen without progesterone can lead to endometrial cancer if you still have your uterus. If your symptoms of menopause have gone away or gotten better, you may be able to reduce or stop hormone therapy.