What is Endometrial Cancer?

Endometrial cancer (also known as cancer of the uterine corpus, uterus or womb) is the most common gynaecologic malignancy (cancer originating in female reproductive organs). The disease normally occurs in postmenopausal women; the average age at diagnosis is about 60 years. There are about 1700 new cases and 230 deaths from the disease every year in Australia . Cancerous (malignant) uterine tumours spread to other tissues and organs if left untreated. Endometrial cancer refers specifically to tumours that originate in the endometrial lining of the uterus. If the tumour originates in the deeper, muscular walls of the uterus, it is called uterine sarcoma. About 90% of all uterine cancers are endometrial. Of these endometrial cancers, there are several subtypes recognised at the cellular level (that is, by the morphology or shape of the tumour cells). Survival is poor for some less common subtypes.

The most common sign of endometrial cancer is unusual bleeding from the vagina, especially bleeding between menstrual periods or after menopause. A precancerous condition called endometrial hyperplasia, or adenomatous hyperplasia, may cause irregular bleeding. This condition can be mild, moderate, or severe. Severe hyperplasia is considered ‘carcinoma in situ' , the earliest detectable stage of the major known subtype of endometrial cancer. If discovered early, this slow-growing cancer is likely to be confined to the uterus, and removing the uterus surgically often eliminates the cancer. In fact, stage I endometrial cancer is successfully treated more than 90 percent of the time. Unfortunately, not everyone can be successfully treated because the cancer may have spread beyond the uterus at the time of diagnosis.

Endometrial cancer is considered an oestrogen-dependent disease. Oestrogen is a hormone that is secreted by the ovaries. It plays an important role in the development of the female reproductive system and is largely responsible for the physiologic changes that occur during puberty, menstruation, and pregnancy. Progesterone is another hormone secreted by the ovaries that also plays an important role. Normally, both oestrogen and progesterone are secreted in controlled proportions. Chronic exposure to oestrogen, without the accompanying balancing effects of progesterone, is considered the major risk factor for endometrial cancer and may play a causal role in the development of the disease.