Endometrial cancer

This article is contributed by Dr Nelson Siu

1. What is endometrial cancer?

Endometrial cancer is cancer arise from the inside lining of the womb, which is the part that slough off in each menstruation. This is different from the cancer arise from the muscle of the womb (leiomyosarcoma) and neck of the womb (cervical cancer).



2. How common is endometrial cancer?

  • Endometrial cancer is the most common cancer of the female reproductive organ in HK and western countries, it is the 4th commonest female cancer. The incidence of endometrial cancer is in rising trend over last 20 years in HK and most western countries. The incidence had tripled in HK from 315 cases in 1999 to 1165 cases in 2018. The current lifetime risk of having endometrial cancer in HK is 1 in 54 women (1.85%).

  • Other types of uterine cancers, eg. leiomyosarcoma (cancer arise from uterine muscle) is pretty rare, it accounts for 1% of all uterine cancer. The incidence of cervical cancer is decreasing, thanks to general uptake of Pap smear and HPV vaccine. 


3. What are the symptoms of endometrial cancer?

Most patients will complain of abnormal vaginal bleeding, these include bleeding after menopause, irregular and shortened menstrual cycle, heavy bleeding and persistent bleeding. In late stage, patient can present with abnormal pelvic mass, abdominal distension, bone pain, shortness of breath ….


4. How does endometrial cancer develop, and what are the risk factors?

  • Endometrial cancer is broadly divided into type I and II.
  • Type I is the good one, usually in younger patients (< 60 years old) and have better prognosis. The cancer developed due to hormonal imbalance (excessive oestrogen). Obese patients, people with irregular long menstrual cycle (eg. polycystic ovarian syndrome) are particularly at risk.
  • Type II is the aggressive type, it account for 10-20% of all endometrial cancer. It usually happen in older age patients (> 60 y.o.). They arise de novo, they are not hormonal related.


5. How to treat endometrial cancer?

  • Surgical removal of the uterus with or without the ovaries is the mainstay of treatment. Lymph nodes dissection may be necessary in order to find out the extent of the disease. Surgery can be performed either by open method or laparoscopically (key hole surgery), depending on the size of uterus and the extent of disease.
  • Patients who are in advanced stage of disease will need radiotherapy or chemotherapy after surgery.

6. How to prevent endometrial cancer?

Multiple national wide studies showed that combine oral contraceptive pills (OCP) are protective for endometrial cancer.  The risk of develop endometrial cancer for long term OCP users (10+ years) is one third that of non-users. 

7. What is the prognosis?

Endometrial cancer usually carries good prognosis. Most patients are diagnosed and treated in early stage. The 5 year survival rate can be up to 97% in patients with early stage I disease.


Irregular menstrual cycle, heavy menses and irregular spotting are common in peri-menopausal women after the age of 40. Incidence of endometrial cancer also start to rise after 40. Therefore, women with abnormal bleeding pattern after the age of 40 should consult their doctor immediately for possibility of endometrial cancer, instead of regarding them as ‘normal peri-menopausal symptoms’.

Updated on 13.11.2020