Uterus, Womb or Endometrium

General Information / Anatomy / Function / Statistics

• The uterus or "womb" is part of the female reproductive system
• It is the part of the body in which a baby grows
• The lower portion of the uterus is called the cervix. It provides the connection between the cavity or body of the uterus and the vagina
• The lining of the uterus is called the "endometrium"
• The term "uterine cancer" generally refers to cancer arising from the lining or endometrium of the uterus, although it can also at times refer to cervical carcinomas or cancers from the muscle of the uterus (myometrium)
• Cancers of the uterus comprise 4% of all cancers but are the commonest cause of malignancies of the female reproductive system, excluding the pre-cancerous lesions like carcinoma in situ of the cervix
• Endometrial cancer of the uterus usually produces early symptoms which leads to early diagnosis with a generally successful treatment outcome
• There has been a significant decrease in the number of women who develop endometrial cancer each year since 1975
• For statistics, please click here

Symptoms / Signs

• Unusual vaginal discharge and/or bleeding are most common symptoms
• Irregular or heavy bleeding during menopause or any bleeding after menopause is abnormal
• During menopause the normal pattern is of gradually decreasing flow with periods coming further and further apart
• Bleeding, between periods, with intercourse, and/or the advent of heavy frequent flows at any stage should be investigated
• Low abdominal pain
• Back pain
• Precancerous conditions that should be watched carefully are:
• Atypical hyperplasia (an overgrowth of the cells in the lining of the uterus) and polyps, which frequently grow in the uterus
• Note: Endometriosis is a benign condition in which tissue resembling the uterine lining occurs inappropriately in various locations in the pelvic cavity outside the uterus
• Symptoms include pelvic pain and pressure symptoms, but occurs in much younger women

Etiology / Carcinogens / Risks

• Post-menopausal women 45 - 70 years old
• 75% of cases occur in women after the age of 50
• White women are affected more commonly than black
• Higher income groups are affected more often than low
• Obese women (particularly with associated conditions of hypertension and diabetes) are at higher risk because more fat produces more estrogen
• Women who have never had children; particularly those with cycles excluding ovulation
• Women who have continued periods after the age of 50
• Women who receive hormone or estrogen therapy. (This usually only applies when estrogen alone is used NOT in conjunction with progesterone. Use of progesterone lowers the incidence of this cancer.) Taking birth control pills does not increase the risk of developing endometrial cancer, in fact it lowers it
• Only 50% of women developing the disease have these risk factors so all women should be aware of the possibility and report any abnormal bleeding to their doctor
• Women who do not ovulate during menstrual cycles

Prevention

• Use of progesterone therapy in women with anovulatory bleeding

Screening

There is no simple, reliable, test for the detection of presymptomatic cancer of the endometrium.  Although a routine Pap smear occasionally detects patients with this disease, it will miss many of them because the Pap smear scrape does not reach the uterine cavity.  Any patient with symptoms suggestive of this disease, particularly post-menopausal bleeding and abnormal bleeding after the age of 40, should see her physician for further investigation.  In post menopausal women who have not had any previous cervical abnormality, the Pap smear should include an aspirate from the endocervical or from the vaginal wall secretions.

Staging (FIGO 1998)

• Stage 0 - In situ
• Stage I - tumour confirmed to endometrium or mid muscular layers of the uterus
• Stage 2a - uterine endocervical (region of opening of the uterine) glandular involvement only
• Stage 2b - uterine invasion to the supporting tissue of the cervix
• Stage 3a - invasion of the uterine serosa and or adnexa (connecting) parts of the uterus; or a positive peritoneal cavity cytology (cancer cells present in p. cavity)
• Stage 3b - vaginal metastases
• Stage 3c - metastases to pelvic and or para-aortic nodes
• Stage 4a - invasion of bladder and or bowel mucosa
• Stage 4b - distant metastases including intra-abdominal and or inguinal nodes

Types

Adenocarcinomas

• Most common type; these cancers usually found in early stages. If found in stage I, the cure rate is approximately 90%.  Some have a squamous component

Sarcomas

• These are tumours that arise from muscle or connective tissue supporting the endometrium
• May be found uncommonly
• Fast growing and can spread quickly to lymph nodes, pelvic structures and distant sites via the bloodstream
• Subtypes of sarcomas include:
  • leiomyosarcoma - accounts for 30% of all uterine sarcomas
  • endometrial stomal sarcoma
  • mixed mesodermal sarcoma

Trophoblastic Tumours

• Trophoblastic Tumours (Hydatidiform mole and choriocarcinoma)
• Uncommon malignant tumour of placental tissue (after birth)
• May start during pregnancy, causing a spontaneous miscarriage or may start after delivery
• Can grow very rapidly and spreads to the lungs
• High incidence in China, Mexico and Philippines
• Protein deficiency, malnutrition and multiple pregnancies are risk factors
• Choriocarcinoma is particularly responsive to chemotherapy
• Generally excellent cure rates

Treatment

Surgery

• For stage I cancers, potentially curative surgery would include a TAH (total abdominal hysterectomy) and BSO (bilateral salpingo oophorectomy in which uterus, ovaries and fallopian tubes are removed.

Radiation

• Can be used pre-operatively to shrink tumours and make them more amenable to surgery
• Can be used post-operatively to try to reduce the risk of recurrence in patients with very advanced tumours.

Chemotherapy

• May be recommended for advanced disease or for certain rare subtypes (papillary serious, small cell) or for cancers that have spread to distant sites.

Hormone Therapy

• May be given when surgery is not feasible or unnecessary
• May be used in advanced or recurrent disease

Revised April 2000

March 2007  We are currently reviewing and updating these pages.  If you have any questions about your cancer and its treatment, please discuss with your oncologist or physician.  Thank you.