What is Endometrial Cancer?
The endometrium is the inner lining of the uterus that thickens and sheds throughout the menstrual cycle, and becomes dormant after menopause. Endometrial cancer is a cancer that has formed from this tissue, and is the most common gynaecological cancer. There are several different types of endometrial cancer and they behave and respond to treatment differently.
What are the symptoms of Endometrial Cancer?
The most common symptom is abnormal vaginal bleeding. This may be any bleeding after the menopause, or as heavy, prolonged and/or irregular bleeding before menopause. Other symptoms may include an abnormal vaginal discharge or spotting, pelvic pain or discomfort, or a change in bowel habit.
What is the cause of Endometrial Cancer?
There are many different histological subtypes of endometrial cancer (diagnosed based on how the cancer appears under a microscope). Additionally, over the last decade our understanding of endometrial cancer has greatly increased, by finding that there are at least 4 different molecular subtypes of endometrial cancer (diagnosed by testing proteins or genes in the cancer).
The exact cause of endometrial cancer is not fully understood. We know that different subtypes of endometrial cancer behave and respond to treatment differently and they may also have differing causes.
Several risk factors for developing endometrial cancer have been identified.
Hormonal imbalance – Oestrogen dominance
An imbalance between oestrogen and progesterone, where oestrogen levels are higher, can overstimulate the endometrial lining, increasing cancer risk.
This imbalance may occur due to:
- Obesity, as fat tissue converts androgens into oestrogen.
- Polycystic ovary syndrome (PCOS), which alters hormone levels.
- Use of oestrogen-only hormone replacement therapy after menopause.
- Certain ovarian tumours that produce excess oestrogen
Obesity
- Obesity is one of the strongest risk factors for endometrial cancer. Excess fat tissue increases oestrogen production, particularly after menopause, which can promote abnormal growth in the endometrium.
Age and Reproductive History
- The risk increases with age, especially after menopause.
- Women who experience early menstruation (before age 12) or late menopause are at higher risk due to prolonged exposure to oestrogen.
- Never having been pregnant also increases risk, as pregnancy reduces the number of menstrual cycles and exposure to oestrogen over a lifetime.
Genetic Factors
- A family history of endometrial or colorectal cancer may indicate a genetic predisposition, such as Lynch syndrome (hereditary non-polyposis colorectal cancer), which significantly raises the risk of developing endometrial cancer.
Lifestyle and Medical Conditions
- Diet and inactivity: High-fat diets and lack of exercise contribute to obesity and increased cancer risk.
- Diabetes: Women with type 2 diabetes have a higher incidence of endometrial cancer, likely linked to obesity and metabolic changes.
Other Factors
- Radiation therapy to the pelvis, or tamoxifen treatment for other cancers may also elevate risk.
Frequently Asked Questions
Ultrasound is useful to evaluate for abnormal thickening or other abnormalities of the endometrium. Endometrial cancer is diagnosed by endometrial biopsy either taken in the clinic, or in the operating theatre as an endometrial curettage.
After a biopsy diagnosis, we use a CT scan of your chest, abdomen and pelvic areas to assess for any signs of cancer spread outside of the uterus. If a CT scan and physical examination show no signs of spread, then surgery is first line treatment if you are assessed and fit for surgery. This is the case for the vast majority of women diagnosed with endometrial cancer.
Surgery involves removal of uterus, cervix, fallopian tubes and ovaries (“total hysterectomy, bilateral salpingo-oophorectomy”), and additional staging biopsies that may include lymph nodes and omentum (a fatty apron that overlies the intestines). In most cases this can be performed with keyhole surgery (laparoscopy or robotic surgery).
For women who present with signs of cancer spread outside of the uterus at diagnosis, their treatment is individualised, but may typically involve a combination of chemotherapy, radiation and in some cases surgery, hormonal therapy or immunotherapy. For women who are medically unfit for surgery, then hormonal therapy or radiotherapy may be an option.
After surgery the operative findings and pathology results are reviewed in a multi-disciplinary team (MDT) meeting where a final diagnosis and “stage” of cancer is defined, as well as a “risk classification” based on several factors. This risk classification relates to the risk of cancer recurrence or progression after surgery.
- Women with a low risk endometrial cancer are typically observed after surgery.
- Women with an intermediate risk endometrial cancer may be recommended to have further treatment with radiotherapy focused at the upper vaginal region (vault brachytherapy)
- Women with an intermediate to high risk endometrial cancer may be recommended to have further treatment with radiotherapy tailored to the pelvic area.
- Women with a high risk endometrial cancer may be recommended to have combined radiotherapy and chemotherapy.
All types of cancer have an associated risk of recurrence following successful treatment. You will be monitored closely following treatment in a schedule tailored to your risk category. If your cancer recurs, treatment options will depend on where the cancer has recurred, what treatment you initially received.
The most common site of recurrence of endometrial cancer is the vagina, therefore any vaginal bleeding or new discharge needs to be reported and assessed. Endometrial cancer can also recur in lymph nodes, the abdominal cavity, liver or lungs, so symptoms such as new and persistent abdominal pain, change in bowel habit, cough, chest pain or breathlessness need to be reported and evaluated.
Uterus preserving treatment for the purpose of fertility is possible in some cases of endometrial cancer using progesterone treatment (Typically a Mirena intra-uterine device).
Preservation of ovaries may also be an option for younger women less than 45 years with low grade and early stage endometrial cancer.
Uterus preserving treatment for the purpose of fertility is possible in some cases of endometrial cancer using progesterone treatment (Typically a Mirena intra-uterine device).
Preservation of ovaries may also be an option for younger women less than 45 years with low grade and early stage endometrial cancer.
If you are facing a new diagnosis of endometrial cancer, write down any questions that come to mind to discuss with your doctor. Bring a family member or friend to your appointment as a second set of ears or to take notes. Reach out to those around you for support, and refer to the support resources on this website.
It is important that you know what is normal for your body. Report any new symptoms early, such as abnormal vaginal bleeding or discharge, or persistent abdominal or pelvic discomfort, pain, or change in bowel habit.